PROCEEDINGS 東海大学紀要農学部 OF SCHOOL OF ......1 東海大農紀要 341－（2015）...

ISSN　1883－1516

東海大学紀要　農学部第　34　巻

2 0 1 5

バーク堆肥を用いたメロンの連作障害の抑制に関する研究　…………………………………………………………………森川充実・田中孝幸・吉田政博………１

チーズの70％エタノール可溶性画分を Sep-PakC18カートリッジにより分離した非吸着および吸着画分のペプチドと抗酸化活性　…………………………………………………………………近藤祐希・安田　伸・井越敬司………７

水生バイオマス「マコモ」の環境保全機能および生産性・機能性に関する研究　………………………仲川侑希・仁木博脩・長谷川大輔・橋本歩果・高橋智保・川合祐加　　　　　　　　　　　　　　　　　　　本田憲昭・岡本智伸・増岡智加子・安田　伸・椛田聖孝………13

English Ability and the Tourism Industry in Siem Reap, Cambodia　……………………………………………………………………………… Jeffrey Stewart Morrow……₁₉

Helping Pre-service Teachers Enter the Community of Practice of Professional Educators through Collaborative Lesson Study　 ………………………………………………………… Michael Rupp……31

PROCEEDINGSOF

SCHOOL OF AGRICULTURETOKAI UNIVERSITY

Vol. 34　　 2 0 1 5

Studies on the Control of the Injury by Continuous Cropping of Melon by Using Bark Compost　……………………………………… Atsumi Morikawa・Takayuki Tanaka and Masahiro Yoshida……１

Peptide and Antioxidative Activity of Non-adsorbed and Adsorbed Fractions Separated　by Sep-PakC18 Cartridge from 70 % Ethanol Soluble Fraction Extracted from Cheeses　………………………………………………………… Yuuki Kondo, Shin Yasuda and Keiji Igoshi……７

Studies on the Function of Environmental Preservation and the Productivity of Aquatic Biomass ʻʻWild Riceʼʼ　…………………………… Yuki Nakagawa, Hironobu Niki, Daisuke Hasegawa, Ayuka Hashimoto,　　　　　　　　　　　　　　　　　Chiho Takahashi, Yuka Kawai，Kensho Honda, Chinobu Okamoto,　　　　　　　　　　　　　　　　　　　　Chikako Masuoka, Shin Yasuda and Kiyotaka Kabata……₁₃


Helping Pre-service Teachers Enter the Community of Practice of Professional Educators through Collaborative Lesson Study　 ………………………………………………………… Michael Rupp……₃₁

東海大学紀要　農学部

第三四巻

二〇一五

hyousi.indd 1 2015/02/28 11:04:55

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堆肥による連作障害の抑制東海大農紀要　34：１－６（2015）

バーク堆肥を用いたメロンの連作障害の抑制に関する研究

森川充実・田中孝幸・吉田政博

Studies on the Control of the Injury by

Continuous Cropping of Melon by Using Bark Compost

Atsumi MORIKAWA・Takayuki TANAKA and Masahiro YOSHIDA

Abstract

　Six times continuous cropping of melon were carried out two times/ year for three years from 2007 to 2009 . Wilting was

observed on the plants cultivated on the soil without bark compost from 2nd continuous cropping and all of the plants

cultivated on the soil without bark compost wilted and died before the harvest of the 4th continuous cropping. On the other

hand, the plants cultivated on the soil with bark compost grew healthy, suggesting that bark compost suppresses the injury by

continuous cropping. To make clear the cause of the injury, the soil without bark compost were divided into two groups before

the 5th continuous cropping; one was sterilized by chloropicrin and the other was not sterilized. The plants cultivated on the

sterili ed soil grew well and set the best fruits in the five treatments, while the plants on the soil without sterili ation grew

slowly, then wilted and died before harvest at the 5th and 6th continuous cropping. Therefore, the cause of the injury by

continuous cropping was considered to be the microorganisms （disease）, but not the nutrient deficiency.

緒　　言

　日本におけるメロンの栽培面積は7,560haで，果菜類の全栽培面積の約６％を占め，アールス系メロンを含む温室メロン（Fig. 1）の栽培面積はメロン全体の約11％を占めており，重要な農産物の一つとなっている（１）．　近年，化学肥料の過度の使用により農耕地の地力低下が問題になっている．地力の維持対策としては，土壌改良材としての有機肥料（２，３，４，５），生ゴミ（６），樹皮（７）などを原料とした堆肥作りが進められており，堆肥など有機肥料は化学肥料と比較して，土壌微生物を増加させ土壌肥沃度を改善するため十分な収穫が得られることが示されている．

　メロン栽培における連作障害の第一の要因は，Fusarium ox ysporum f. sp. melonisによるつる割病などの土壌伝染性の病気の蔓延である．Fusarium菌は一度発生すると，２～３年間休作しても厚膜胞子として病原菌は残留し，再び発生することが多い．そこで抵抗性品種に接ぎ木をする栽培が行われているが，糖度低下など品質

の悪化があることなどから，アールス系メロンでは接ぎ木をせず，土壌消毒による防除が広く行われている．しかし，薬剤による土壌消毒は，有害物質の残留問題や環境汚染が懸念される．　一方，有機肥料などの中には肥料の中に微生物が多く含まれ，バーク堆肥による R hiz octonia solani（苗立枯病菌）の抑制（8），キクやアマの F. ox ysporum菌による萎凋病の抑制（９），園芸植物の生ゴミなどから作られた堆肥中の微生物によるメロンつる割病の抑制（10，11，12）など，微生物の持つ拮抗作用による病害の抑制効果が報告されている．　さらに，このような拮抗微生物の作用だけでなく，有機肥料で育てられた作物そのものに病気に対する抵抗性が引き起こされているという研究報告もある（13，14）．また，太陽光を用いた土壌消毒（15）や耐病性のメロンの育種（16，17）による病害対策もなされている．　このように，有機物質の土壌改良剤としての投与は，土壌微生物の拮抗性の向上などにより生産性を向上させる可能性がある．一方で，有機肥料の投与は化学肥料に比べて高い収量を示したものの，ネコブセンチュウの発生が多かったという報告もある（３）．また，バーク堆東海大学農学部

（Received 19 November 2014; Accepted 4 January 2015）

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森川　充実・田中　孝幸・吉田　政博

肥を土壌に施肥する場合，未熟なバーク堆肥では，発芽や初期生育の抑制あるいは窒素飢餓などの生育障害を起こす危険が大きいとされ，バーク堆肥投与の効果に関する検討は十分に行われていない．　そこで，本研究では土壌消毒に頼らない連作栽培の確立を目指し，連作障害の抑制に効果があるともされているバーク堆肥および有機肥料を用い，2007年春からガラス温室内においてメロンの連作栽培を行い，慣行の化学肥料栽培などとの比較試験を実施した．

材料および方法

　試験は年間春作および秋作の２作とし，それぞれメロン品種として ʻ アールスセイヌ夏Ⅲ ʼ（八江農芸㈱），ʻ アールスセイヌ秋系 ʼ（八江農芸㈱）を用い（Fig. 1），東海大学農学部付属農学教育実習場のガラス温室内で行った．播種は，2007年は３月23日（１作目）および７月23日（２作目）に，2008年は３月24日（３作目）および７月23日（４作目）に，2009年は３月23日（５作目）および７月21日（６作目）に行い，定植は，それぞれ2007年は４月16日および8月8日に，2008年は４月23日および8月７日に，2009年は４月16日および７月21日に隔離ベッド（３m×0. 56m）で株間43cmで行った．試験区として「バーク堆肥＋土・有機肥料連作（Ａ）区」，「バーク堆肥＋土・化学肥料連作（Ｂ）区」，「バーク堆肥＋土・化学肥料単作（Ｃ）区」および「土・化学肥料連作（Ｄ）区」の４区を設けた．また，Ｄ区では，２作目以降に萎凋・枯死する株が多く発生したことから，

その原因検討のために５作目（2009年春作）と６作目（2009年秋作）では，Ｄ区を土壌消毒する「Ｄ１区」，しない「Ｄ２区」の二つにさらに試験区を分け，同様に４反復で試験した．窒素，リン酸，カリウム，カルシウムおよびマグネシウムが元肥は全ての試験区において同量になるように調整し，追肥は行わなかった（Table 1）．　Ａ，ＢおよびＣ区の土壌には，バーク堆肥：土を１：１（ｖ / ｖ）で混合し，炭酸苦土石灰で pH 6. 15，EC 0. 33ms/ cmに調整した栽培土壌（八代ソイル（株））を用いた．なお，Ｃ区は作毎に土壌を新しく入れ替えて単作区とした．全試験区における調査株は，各試験区中央の３株を対象とし，ラテン方格法により４反復で行った．

　メロンは立体仕立てとし，腋芽は下から10節目まで取り除き，十分大きくなった後には，風通しをよくするために第３葉まで取り除いた．交配は，第11節～15節の間に出た腋芽の第1節に着く雌花（両全花）に人工で行った．摘芯は25節で行い，着果後，形の良い果実を一つだけ残し，その他は摘果した．　温室内の気温は，自動タイマーにより設定した．20℃以下になると暖房が入り，また，26℃以上になると側面および天井の扉を開いて調節した．定植後の潅水は潅水チューブを用い，午前8時，12時および午後４時の１日３回，１回あたり７～8分間とし，収穫２週間前からは，１日おきに５分間，それぞれ自動タイマーによって行った．収穫10日前からは潅水を行わず，水切りを行った．　生育調査は，定植した日から開始し，展開葉数，葉長，葉幅および葉緑素量（KONICA MINOLTA SPAD‒502を用い）を毎週測定した．また，交配後10日目からは，果実の球高および球幅を測定した．収穫調査は作によって異なるが，交配後50日から60日の間の同じ日数の日に収穫して行い，植物体においては葉長，葉幅，葉緑素量，

Fig. 1. Fruit of melon cv. Earlʼs Seinu Natsu Ⅲ

Table 1. Composition of basal dressing fertilizerOrganic fertilizer

Kg/10a N P2O5 K2O CaO MgO

Momotaro compost 248.8 11.2 10.7 6 13.7 2.5

Magnesium sulfate 18.4 －－－－ 4.6

Dublin12 13.4 － 4.7 －－ 1.1

Neomagreen 76.4 －－－ 44.3 15.3

Total 11.2 15.4 6 58 23.5

Chemical fertilizer

Kg/10a N P2O5 K2O CaO MgO

Kamoto melon 80 140 11.2 8.4 5.6 －－Neomagreen 100 －－－ 58 20

Dublin12 20 － 7 －－ 1.6

Magnesium sulfate 7.6 －－－－ 1.9

Potasium chloride 0.655 －－ 0.4 －－Total 11.2 15.4 6 58 23.5

p01-06_morikawa.indd 2 2015/02/26 11:38:29

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堆肥による連作障害の抑制

地上部重および病害虫発生の有無を調査し，果実においては，球高，球幅，果実重，果肉の幅，糖度，外見の品質，ネットの張り，種子重および種子数を調査した．

　栽培終了後，各試験区のベッド中央の土を採取し，土壌三相計（大起理化工業㈱，DIK‒1120）で土壌の三相を調べ，さらにその土壌は土壌分析に供試した．分析は，アンモニア態窒素 NH4‒N，硝酸態窒素 NO3‒N，リン酸P2O5，カルシウム CaO，マグネシウムMgOおよび腐食Humusを土壌・作物体総合分析装置（富士平工業㈱，SFP‒3）の分光光度計で，カリウム K2Oは同じく炎光光度計で測定し，pHは pHメーター（㈱堀場製作所，Ｆ‒8）で，ECは電気伝導度計（㈱竹村電気製作所）を用いて測定した．

結果および考察

　2007年から2009年にかけて行った６回のメロンの連作栽培で収穫時における最大葉の葉長，葉幅，果実を除く地上部重および葉緑素量を Fig. 2，3，4 および５に示す．　連作栽培において土のみのＤ区では，１作目の生育は有意に優れていたが，栽培を繰り返す毎に生育が悪くなり，４作目では収穫前にすべての株が萎凋し，枯死した（Fig. 6）．一方，連作をしても，バーク堆肥を加えたＡ区とＢ区では，Ｄ区と比較して４作目まで生育が良く，枯死する株は少なかった．　このことから，メロン栽培においてバーク堆肥を加える事は連作栽培に良好な効果があったものと考えられた．そこで，土のみのＤ区でメロンの生育の悪くなった原因が肥料の欠乏による生理障害であるか，あるいは生

物性の病原菌であるかを調べるため，５作目の栽培前にＤ区の用土を２分し，その一つをクロールピクリン剤で消毒してＤ１区とし，消毒しなかったものをＤ２区とした．５作目においては葉長（Fig. 2），葉幅（Fig. 3），地上部重（Fig. 4）および葉緑素（Fig. 5）でバーク堆肥＋土・化学肥料単作（Ｃ）区および土・化学肥料連作・消毒有り（Ｄ１）区が優れ，春作・秋作ともにバーク堆肥＋土・有機肥料連作（Ａ）区および土・化学肥料連作・消毒無し（Ｄ２）区が劣った．Ｄ２区は栽培初期から生育が悪く，後半になっても生育の悪化は回復しなかった．Ｄ２区で劣った理由は，４作目から見られた連作による何らかの障害が継続したためと思われた．これに反してＤ１区で生育が回復したのは，土壌消毒によって土壌中

335

Fig. 2. Effect of culture media and fertilizers on the leaf length

of melon at harvest time． 340

A Organic fertilizer, continuous cropping on the mixed medium

of bark compost and soil.

B Chemical fertilizer, continuous cropping on the mixed medium

of bark compost and soil.

C Chemical fertilizer, cropping on the newly prepared soil on 345

the mixed medium of bark compost and soil.

D1 Chemical fertilizer, continuous cropping on the soil

without bark compost, sterilized before 5th cropping

D2 Chemical fertilizer, continuous cropping on the soil

without bark compost, not sterilized before 5th cropping 350

a n.s.

a

b

b

ab

aab b

b

ab

a bb

b

b

b

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b

a

a

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a0

5

10

15

2 0

2 5

1st 2nd 3rd 4th 5th 6th

Leaf

le

ngt

h (

cm

)

Cropping time

ABCD1D2

16

Fig. 2 . Effect of culture media and fertilizers on the leaf length of melon at harvest time.

A: Organic fertilizer, continuous cropping on the mixed medium of bark compost and soil.

B: Chemical fertilizer, continuous cropping on the mixed medium of bark compost and soil.

C: Chemical fertilizer, cropping on the newly prepared soil on the mixed medium of bark compost and soil.

D₁: Chemical fertilizer, continuous cropping on the soil without bark compost, sterilized before 5th cropping

D2: Chemical fertilizer, continuous cropping on the soil without bark compost, not sterilized before 5th cropping

365

Fig. 4. Effect of culture media and fertilizers on the top weight of

melon without fruit at harvest time． See the Fig.2 for abbreviation.

a n.s.b

bb

b

a b

bb

b

ab

b

b

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a

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a

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300

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500

600

700

800


Top

weig

ht

(g)

Cropping time

ABCD1D2

18

Fig. ₄ . Effect of culture media and fertilizers on the top weight of melon without fruit at harvest time. See the Fig. 2 for abbreviation.

370

Fig. 5. Effect of culture media and fertilizers on the chlorophyll

contents（ SPAD） of melon at harvest time． See the Fig.2 for 375

abbreviation.

an.s.

b

b

b

n.s.

a

ab

b

b

a

a

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0

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25

30

35

40


Chlo

rophyl

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onte

nts

Cropping time

ABCD1D2

19

Fig. 5 . Effect of culture media and fertilizers on the chlorophyll contents(SPAD)of melon at harvest time. See the Fig . 2 for abbreviation.

355

Fig. 3. Effect of culture media and fertilizers on the leaf width

of melon at harvest time． See the Fig.2 for abbreviation.

360

an.s.

a

b

b

ab

a

abb

b

ab

a b

b

bb

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a0

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25


Leaf

w

ideth

(cm

)

Cropping time

ABCD1D2

17

Fig. ₃. Effect of culture media and fertilizers on the leaf width of melon at harvest time. See the Fig. 2 for abbreviation.

p01-06_morikawa.indd 3 2015/02/26 11:38:30

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の生物的要因，特に病原菌と害虫が死滅したためで，４作目までのＤ区で見られた萎凋症状は肥料欠乏などによるものではなく，一般に考えられているように土壌伝染性の病害虫によるものだと思われた．　また，データには示していないが，初期生育におけるこれらの項目についてはバーク堆肥＋土という点では共通であった単作のＣ区に比べて，連作のＡ区（有機肥料区）およびＢ区（化学肥料区）がわずかに悪かったのは，Ｄ区より遅れて連作障害が現れた結果と考えられた．しかし，生育後半においてＡ区およびＢ区は回復し，逆に初期生育において優れていたＣ区で悪くなった．このことは新しい用土を用いたＣ区は緩衡作用，すなわち保肥能力が弱く，栽培初期には肥料がよく効くが，後半には流出による肥料欠を起こしたためと考えられた．言い換えれば，Ｃ区は砂や石のように保肥能力，すなわち地力がなく，交配を始めた５月18日以降には，葉や茎に栄養が回らず，葉色も薄くなったものと考えられた．　同様にデータには示していないが，土壌分析の結果，リン酸およびカルシウムは，バーク堆肥を入れているＡ区，Ｂ区あるいはＣ区の方が入っていないＤ区より多かった．５，６作目でＤ２区のアンモニア態窒素およびカリウムが多かったが，これは連作障害によりメロンの

生育が悪くなり，肥料が吸収されなかったためと思われた．これとは逆に，栽培後半に肥料欠をおこしたと思われる用土を作毎に入れ替えたＣ区は葉肥である硝酸態窒素が試験区の中で最も低く，このために後半の生育が悪くなったものと思われた．マグネシウムについては試験区間で明らかな差異は見られなかった．腐食についてはバーク堆肥を入れているＡ区，Ｂ区およびＣ区が多く，土のみの区であるＤ区は少なかった．　一方，６作目の秋作では，葉長，葉幅および葉緑素において，Ｄ１区は５作目の春作に比べてＡ区，Ｂ区より劣った．これは２作目と同様，連作障害が始まったためと考えられた．　収穫時における果実の球高，球幅，果実重および糖度を Fig. ７，8，９および10に示す．

Fig. 6．Wilting of plants in the treatment D2.

395

Fig. 7. Effect of culture media and fertilizers on the fruit height

of melon at harvest time． See the Fig.2 for abbreviation. 400

ab b n.s. b n.s.ab

bb

bab a abab

c

bc

a

a

0

20

40

60

80

100

120

140


Fru

it heig

ht

(mm

)

Cropping time

ABCD1D2

21

Fig. 7 . Effect of culture media and fertilizers on the fruit height of melon at harvest time. See the Fig. 2 for abbreviation.

410

Fig. 9. Effect of culture media and fertilizers on the fruit weight 415

of melon at harvest time． See the Fig.2 for abbreviation.

a

b

b

b

bc abab

ab

ab

b

bcaba

aab

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it w

eig

ht

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Cropping time

ABCD1D2

23

Fig. ₉ . Effect of culture media and fertilizers on the fruit weight of melon at harvest time. See the Fig. 2 for abbreviation.

420

Fig. 10. Effect of culture media and fertilizers on the soluble solid

contents (brix) of melon at harvest time． See the Fig.2 for

abbreviation. 425

n.s.

bn.s. b

n.s.n.s.

b b

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4

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Solu

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lid conte

nts

Cropping time

A

B

C

D1

D2

24

Fig. ₁₀ . Effect of culture media and fertilizers on the soluble solid contents (brix) of melon at harvest time. See the Fig. 2 for abbreviation.

405

Fig. 8. Effect of culture media and fertilizers on the fruit width of

melon at harvest time． See the Fig.2 for abbreviation.

n.s.a b c

b n.s.a ab bcba ab ab

ab

bb

a a

a

0

20

40

60

80

100

120

140


Fru

it w

idth

(m

m)

Cropping time

ABCD1D2

22

Fig. ₈ . Effect of culture media and fertilizers on the fruit width of melon at harvest time. See the Fig. 2 for abbreviation.

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堆肥による連作障害の抑制

　収量調査の結果は生育調査の結果と概ね同じであった．１作目では土だけのＤ区がバーク堆肥を加えた区より果実は有意に大きかったが，作が進むにつれて小さくなり，５作目のＤ２区では有意に小さくなった（Fig. 7，8）．また，定植前に土壌消毒した５作目のＤ１区の果実は大きくなった．しかし，４作目のＤ区などでは，収穫前に株が萎凋し枯れていても，それまでに果実がある程度肥大していたことでその差は比較的小さかった．果実重は，果高と果幅の積に比例するので同様の傾向がより強く表れ（Fig. 9），10a当たりの収量に換算すると健全な試験区で約４tとなった．糖度は，収穫直前までの株の健全さが影響するので，果実の大きさや重さより連作障害の影響が強く表れた．健全な株の糖度は12～15であったが，４作目以後のＤ区あるいはＤ２区の糖度は９と低くなった．５作目で土壌消毒を行ったＤ１区の果実の糖度は最も高く，Ｄ２区と有意な差が見られた（Fig. 10）．データに示していないが，メロン果実の糖度，形，ネットの張りを考慮して品質を上物，中物あるいは下物に分けて10a当たりの収量を分析した結果でもバーク堆肥を用いた効果と土壌消毒の効果が認められた．

　本試験における連作栽培による生育後期に株が萎凋する原因は，土壌伝染性の病害虫によるものと思われた．バーク堆肥を入れていない土だけで連作したＤ区で見られた萎凋症状のように，それらの連作障害としての原因が，F. ox ysporum f. sp. melonisによるつる割病のような強い病原菌による病害とは異なり，萎凋症状を起こす菌の種類が複数で特定できないことも少なくない．本研究でもこれらの萎凋株より病原菌の分離を４回実施し，合計423個体の発病根サンプルから337菌株を得，菌叢により26タイプに分け，それらの特徴と形成された胞子などを観察した．典型的な本症を示す株では，根の基部が赤く変色して，コルク化が進み，茎が空洞化することから，当初この萎凋症をメロン紅色根腐病と推定したが，その病原菌である Pyrenochaeta terrestrisの特徴を持つ菌は検出されず，原因菌の同定には至らなかった．この原因解明については今後の検討が必要である．用いた土はウリ科の作物を栽培したことのない土壌で，このように，連作をすれば強い病原菌ではないとしてもメロンの生育を悪化させる土壌中の微生物が増加し，生育に障害を起こすものと考えられた．実際，この萎凋症状は４作目までのバーク堆肥の入っていない土だけのＤ区と５作目および６作目のＤ２区でも発生が見られた．したがって，栽培土壌へのバーク堆肥の添加は，そのような有害微生物の抑制に有効であるものと考えられた．　この他，うどんこ病，オンシツコナジラミ，アブラム

シ，ハモグリバエは早くからすべての区で見られたので一般の化学農薬で抑えた．発生には試験区間で差の見られたこともあったが，年により傾向が異なった．これは，うどんこ病，アブラムシ，ハモグリバエおよびオンシツコナジラミが土壌伝染性でないことからで，試験区間の差は株の生育の旺盛さなどが原因になったものと思われた．サツマイモネコブセンチュウは５作目からどちらかというとバーク堆肥を加えた区で発生が始まった．　バーク堆肥は肥料としての効用（２，３，４，５，６）より土壌改良材としての効用が期待されている（７）．本研究では，データには示していないが，バーク堆肥を入れた試験区Ｂでは，入れなかった土だけの試験区Ｄよりリン酸およびカルシウムが多く，また，バーク堆肥を入れた試験区では固相の割合が低かった．逆に気相あるいは液相の割合が高かったことは，植物の根の張りによい影響があったものと思われた．また，堆肥の中には多くの拮抗微生物が存在し，堆肥を用いることによって病原菌接種による発病を抑える報告がある（8）．そのような研究では特に病原性の強い F. ox ysporum菌が主に用いられている（９，10，11，12）．しかし，実際の圃場における病原菌接種を行わない試験研究は，ほとんど行われていない．本研究では，このような背景を理解した上で敢えて接種をしない条件下で，またウリ科作物の重大な病原菌が存在しないと考えられる未栽培土壌を用いて連作試験を行った．その結果，予想より短期間の１年目の２作目で連作障害と考えられる生育後期に萎凋する症状の発生がバーク堆肥を加えない土だけの栽培区で始まり，２年目の４作目では収穫前にすべての株が枯死するまでに至った．一方，バーク堆肥を加えた区でのその発生は極めて軽減された．さらに，発生した連作障害は土壌消毒によっても改善することができた．このように，バーク堆肥を栽培土壌に添加することは，土壌消毒に頼らないメロンの連作障害の対策として，その障害の発生の抑制に有効であると考えられた．

要　　約

　2007年から2009年にかけて年に２回（計６回）メロンを連作栽培し，バーク堆肥による連作障害抑制効果を試験した．栽培処理区は「バーク堆肥＋土・有機肥料連作区」，「バーク堆肥＋土・化学肥料連作区」，「バーク堆肥＋土・化学肥料単作区」および「土・化学肥料連作区」とした．その結果．バーク堆肥を用いない土のみの区で２作目からメロンの株の萎凋が見られ，４作目では収穫前に全ての株が萎凋し枯死した．一方，土にバーク堆肥

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を加えた区では萎凋する株は発生しなかったことから，バーク堆肥の連作障害抑制効果が認められた．　５作目では，萎凋した原因を明らかにするため，土だけで連作した区をさらに二つの区に分け，クロールピクリンで土壌消毒した区（消毒区）と消毒をしなかった区（無消毒区）を設けた．無消毒区では，５作目および６作目においても４作目以上に初期生育の遅れが見られたのに対し，消毒区では健全に生育し，収量および品質が対照区に比べ優れた．土壌消毒により萎凋症状の発生が改善されたことから，この原因は土壌中の生物性要因であり，土壌伝染性の病原菌であると考えられた．

謝　　辞

　本研究に際し，本学，蔬菜花卉園芸学研究室の岡部貴紀氏，藤本圭介氏，高岡秀昭氏並びに同研究室の学生諸君にお世話になった．ここに深く感謝の意を表す．

引用文献

１）農林水産省， 2013，都道府県別の作付面積， 10a当たり収量，収穫量および出荷量メロン計，作況調査（野菜）確報 H. 24年産野菜出荷統計2012．

２）河田弘，1981，バーク（樹皮）堆肥　製造・利用の理論と実際，博友社，東京．

３）Morra, L. , Bilotto, M. and Magnifico, V . , 2003, Acta

Hort. 614, 781‒785. ４）Bertschinger, L. B. and Anderso, J. D. , 2004, Acta Hort.

638, 249‒254.５）Makinde, E. A. , Ayoola, O. T. and Akande, M. O. , 2007,

Aust. J. Basic Appl. Sci. 1（1）, 15‒19.６）Means, N. E. , Starbuck, C. J. , Kremer, R. J. and Jett, L.

W. , 2005, Compost Sci. Util. 13 （2）, 116‒121.７）今野一男，平井義孝，東田修司， 1986，北海道立農

試集報， 55， 33‒43．8）Nelson, E. B. and Hoitink, H. A. J. , 1983, Phytopathology

73 （2）, 274‒278．９）Chef, D. G. , Hoitink, H. A. J. and Madde, L. V . , 1983,

Phytopathology 73 （2）, 279‒281．10）Ros, M. , Hernandez, M. T. , Garcia, C. , Bernal, A. and

Pascual, J. A. , 2005, J. Appl. Microbiol. 98（4）, 845‒854．11）Suarez-Estrella, F. , V argas-Garcia, C. , Lopez, M. J. , Capel,

C. and Moreno, J. , 2007, Crop Prot. 26（1）, 46‒53.12）Z hao, Q . , Dong, C. , Yang, X . , Mei, X . , Ran, W. , Shen, Q .

and X u,Y. , 2011, Appl. Soil Ecol. 47（1）, 67‒75.

13）Pharand, B. , Carisse, O. and Benhamou, N. , 2002, Phytopathology 92, 424‒438.

14）Yogev, A. , Raviv, M. , Hadar, Y. , Cohen, R. , Wolf, S. , Gil,

L. and Katand, J. , 2010, Biol. Control 54, 46‒51. 15）Tamietti, G. and V alentino, D. , 2006, Crop Prot. 25（4）,

389‒397. 16）Sakata, Y. , Oyabu，T. , Yabe, K. , Sugiyama, M. ,

Morishita, M． Sugahara, S. and Saito, T. , 2006, JARQ

40 （2）, 177‒181．17）Crosby, K. , Wolff, D. and Miller, M. , 2000, HortSci. 35（4）, 681‒683.

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チーズペプチドの Sep-PakC18カートリッジによる分離東海大農紀要　34：７－12（2015）

チーズの70％エタノール可溶性画分を Sep-PakC18カートリッジにより分離した非吸着および吸着画分のペプチドと抗酸化活性

近藤祐希 *,**，安田　伸 *，井越敬司 *

Peptide and Antioxidative Activity of Non-adsorbed and Adsorbed Fractions Separated by Sep-PakC18 Cartridge from 70% Ethanol Soluble Fraction Extracted from Cheeses

Yuuki KONDO, Shin YASUDA and Keiji IGOSHI

Abstract

　To clarify the properties and antioxidative activity of peptides in cheeses, peptides in 70% ethanol-soluble fractions of 14 kinds of commercial cheeses were separated to non-adsorbed and adsorbed fractions with the Sep-Pak C18 Cartridge. The

contents of peptides in 70％ ethanol-soluble and adsorbed fractions were measured, and the ratio of peptides in the adsorbed

fraction to peptides in the70％ ethanol-soluble fraction was calculated. This ratio was greater than 85% in lactic acid bacteria-

ripened cheeses, such as Gouda, Maribo, Edam and Cheddar. However, other cheeses had ratios of less than 80%, especially

surface mold cheeses such as Camembert and Brie, and blue mold-ripened cheeses such as Danablu and Blue had the lowest

ratios（50-60%）.　Antioxidative activity of non-adsorbed and adsorbed fractions separated with the Sep-Pak C18 cartridge was examined by

the β -carotene decolorization method.　 Antioxidative activity was found in both fractions of all cheeses, showing that a

minimum of two antioxidative ingredients are found in each cheese, i. e. , those non-adsorbed and adsorbed by the Sep-Pak C18 Cartridge. The relationship between the antioxidative activity and amount of peptide in the non-adsorbed and adsorbed

fractions was examined. A relatively high correlation was observed between the antioxidantive activity and amount of peptide,

suggesting that antioxidantive activity occurred due to the peptides contained in both fractions.

緒　　言

　チーズは，5,000年以上の歴史を持ち，世界の食文化の中でも最も卓越した食品として乳文化の最高位に位置している．チーズの歴史や文化をほとんど持たなかった日本でも，チーズの消費量は増加の一途をたどり（１），これは近年の急速なライフスタイルの変化や食の国際化の影響によるものと考えられる．今後とも，我が国の食生活において，益々より身近な食品の１つになっていくと考えられ，チーズの栄養性や嗜好性のみならず健康効果等の食品の三次機能についての研究が期待される．しかし，これまでのチーズ研究の多くは，主として食品の一次機能（栄養性）や二次機能（風味、呈味、組織形

成）の改善等を目的としたもので（２），食品の三次機能（生体調節機能）の視点からはほとんどされてこなかった．したがって，チーズ研究において，チーズの新たな有用性，すなわちヒトの健康とどのように関わっているかというチーズの三次機能の視点からの研究がこれからの重要な課題といえる．

　最近，生体内で発生する活性酸素やフリーラジカル等による酸化ストレスが，人の老化や生活習慣病に関与することが明らかになってきた（３）．これら活性酸素は我々の体に重要な役割を果たしているものの（４），活性酸素による過剰な酸化ストレスが生じると，生体障害を起こし，老化に密接に関連した疾病，特に生活習慣病と呼ばれるガン，動脈硬化および糖尿病の合併症などの疾病を引き起こすと考えられている（５）．したがって，酸化ストレスの制御や軽減化する予防医学の視点から，食品の抗酸化能とその成分並びにその検索に関する研究

＊東海大学農学部＊,＊＊現在協同乳業（株）

（Received 19 November 2014; Accepted 4 January 2015）

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近藤　祐希・安田　伸・井越　敬司

が行われてきている．しかし，このような食品中の抗酸化物質の検索や食品の抗酸化能に関する研究の多くは，野菜や果物を中心とした植物性食品を対象としたものがほとんどであり（６,７），動物性食品の抗酸化能に関する報告は少なく，また乳発酵食品のような発酵食品を対象とした抗酸化能に関する研究はさらに少ない．　そこで我々は，保健効果や予防医学に関わる三次機能についてほとんど明らかにされていないチーズに着目し，チーズの抗酸化活性とその成分について明らかにする研究を実施している．既に市販チーズ14種類の70％エタノール（以下70％ Et-OH）可溶性画分に抗酸化活性を見出し，また熟成が進行したチーズに活性が高いことを報告した（8）．そこで本研究では，チーズの70％ Et-OH

可溶性画分のペプチドの性質と抗酸化活性について調べるため，同画分のペプチドを Sep-PackC18カートリッジを用いて非吸着および吸着画分に分離し，それぞれのペプチド量と両画分の抗酸化活性について調べたので，報告する．


１．供試チーズ　供試した14種類のチーズうち，ブルーチーズを除く13種類のチーズは熊本市内のチーズ専門店より購入し，ブルーチーズは雪印メグミルク（株）のチーズ研究所より求めた．チーズはいずれも基本的にスターターとして乳酸菌が使用され，本研究で使用されたゴーダ，マリボー，エダムおよびチェダーはスターターとして乳酸菌のみが使用されている．マンステールおよびポンレベックはBrevibacterium linens，ダナブルーおよびブルーはPenicillium roqueforti，カマンベールおよびブリーはPenicillium camemberti，エメンタールおよびグリエールは Propionibacterium freudenheichiがスターターとして乳酸菌の他に添加されている．また，モツアレラチーズは熟成させていない非熟成チーズである．

２．チーズの70%Et-OH 可溶性画分の調製　既報（8）に準じ，次の通り行なった．チーズ20 gに蒸留水80 mlを加え，ストマッカー（オルガノ株式会社）を用いて15分間破砕し，チーズ懸濁液を調製した．調製後，全量を100 mlに定溶し，遠心分離（6,000 rpm，4℃，20分）により脂肪と不溶物を除去した．得られた上清は濾紙（Whatman113）にて全量濾過し，濾液３容量に対してエタノールを７容量の割合で混合し，４℃で一晩静置した．静置後，遠心分離（10,000rpm，４℃，

20分）にて不溶物を除去し，得られた上清を各種チーズ70%Et-OH可溶性画分とした．　３．Sep-PackC18カートリッジを用いた70％ Et-OH　　可溶性画分の分画　各種市販チーズ70%Et-OH画分5 mlをエバポレーターにて乾固し，5 mlの蒸留水に溶解させた．溶解後全量を Sep-PakC18カートリッジ（Waters Co. 米国）に負荷した．負荷後，蒸留水10 mlで非吸着画分を溶出し，次いで80％アセトニトリル10 mlで吸着画分を溶出した．得られた両画分は全量乾固し，それぞれ70% Et-OH 5 ml

に溶解した．溶解後，調製された両画分の抗酸化活性およびペプチド量を測定した．　

４．ペプチドの定量　70％ Et-OH可溶性画分および Sep-Pack C18カートリッジにより回収された各種市販チーズの非吸着および吸着画分のペプチドを Lowry法（９）により，牛血清アルブミンを指標に測定した．

５．β - カロテン法による抗酸化活性の測定　抗酸化活性の測定は，工藤らの方法（10）に準じ，既報（8）に従い行った．すなわち，試験管に試料100μl

を入れ，次いでリノール酸－β‒カロテン溶液4. 9 mlを入れた．470nmにおける吸光度（A0）を測定した後，直ちに50℃の恒温槽に放置した．放置開始30分後の吸光度（A30）を測定し，反応直後における吸光度からの減少量⊿ A（A0 － A30）を求めた．一方，試料の代わりに70％Et-OH のみを入れたコントロール溶液の減少量を⊿ B（B0 － B30）とし，下記の式により抗酸化活性を求めた．活性測定は4回繰り返して行い，その平均値を示した．　抗酸化活性（%）＝｛（⊿B－⊿A）/ ⊿B｝×100


１．チーズの70％ Et-OH 可溶性画分のペプチド量と　　Sep-PakC18によるペプチドの分離　各チーズから抽出した70％ Et-OH可溶性画分中のペプチド量を調べ，その結果を Table 1 に示した．70％Et-OH可溶性画分中のペプチドはポンレベック（5 . 45㎎/ ml）およびマンステール（5 . 12㎎ / ml）のリネンス菌熟成チーズが最も多く，次いでダナブルー（4. 32㎎ / ml）およびブルー（3 . 43㎎ / ml）の青カビ熟成チーズであった．モツアレラを除くその他の白カビ，プロピオン酸菌および乳酸菌熟成チーズは１～2㎎ / mlのペプチド量で，

p07-12_kondo.indd 8 2015/02/26 11:38:39

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チーズペプチドの Sep-PakC18カートリッジによる分離

最も少なかったのは非熟成タイプのモツアレラ（0. 09㎎/ ml）であった．チーズ中のペプチドは熟成とともに増加することから，70％ Et-OH可溶性画分中のペプチド量は熟成と関係していると考えられる．本実験で使用したチーズの中で，マンステールやポンレベックそしてダナブルーおよびブルーはその他のチーズより多くのペプ

チド量が見出された．この結果はこれらチーズがその他のチーズより熟成が進行していることを意味した．実際マンステールやポンレベックそしてダナブルーおよびブルーはチーズの中でも熟成率が高いことが知られており（11），ぺプチドの最も少ないモツアレラチーズは非熟成チーズに分類されている．

　70％ Et-OH可溶性画分中のペプチドを Sep-PakC18カートリッジを用いて非吸着と吸着画分に分離し，両画分のペプチド量を測定した（Table 1）．その結果，Sep-

PakC18カートリッジの吸着画分でペプチド量が最も多かったのはポンレベック（4. 21 mg/ ml）およびマンステール（3. 75 mg/ ml）で，次いでダナブルー（2. 80㎎ /

ml）およびブルー（1. 93㎎ / ml）であった．最も低かったモツアレラ（0 . 06 mg/ ml）を除いた白カビ，プロピオン酸菌および乳酸菌熟成チーズはほぼ1 mg前後から1 . 5㎎ / mlであった．一方，カートリッジの非吸着画分は吸着画分に比べ少なく，その中でダナブルー（1 . 37 mg/

ml），ブルー（1. 18 mg/ ml），マンステール（0. 75㎎ / ml），ポンレベック（1. 00㎎ / ml）が比較的高かった．それ以外のチーズは0. 6㎎ / ml以下で，特にゴーダ，マリボー，エダムおよびチェダーの乳酸菌熟成チーズのペプチドは少なかった（0. 1～0. 25㎎ / ml）．Sep-PakC18カートリッジでは，親水性成分は吸着せず，疎水性成分が吸着する．したがって，Sep-PakC18カートリッジの80％アセトニト

リル液で溶出させた吸着画分のペプチドは疎水性ペプチドとして捉えることができる．そこで，同カートリッジにより溶出した吸着画分の疎水性ペプチド量を各種チーズの70％ Et-OH可用性画分中のペプチドに対する割合でそれぞれ求めた（B/ A）．その結果，ゴーダ，マリボー，エダムおよびチェダーの乳酸菌熟成チーズは70％ Et-OH

可溶性画分中のペプチドの84％以上が疎水性ペプチドであることが推定された．その他のチーズは80％以下であった．特に，カマンベールやブリーの白カビ熟成チーズおよびダナブルーやブルーの青カビ熟成チーズは55～65％と小さかった．すなわち，70％ Et-OH可溶性画分中の疎水性ペプチドの溶出割合はチーズの種類によって異なるものの，乳酸菌熟成チーズは他のチーズより疎水性ペプチドの割合が高く，また青カビや白カビ熟成チーズの疎水性ペプチドの割合が少ないことが知られた．この結果は乳酸菌熟成チーズは疎水性ペプチドの生成が高く，青カビや白カビ熟成チーズは親水性ペプチドの生成が比較的高いチーズであることが示唆された．乳酸菌熟

Table 1　Peptide contents of 70%Et-OH soluble fraction,Sep-Pack C18 non-adsorbed and adsorbed fractions

cheesePeptide Content (mg/ml)

B/A(%)70%EtOH-SolubleExtract(A)

Non-AdsorbedFraction

AdsorbedFraction(B)

Mozzarella 0.09 0.00 0.06 －Munster 5.12 0.75 3.75 73.2

Pont-l’Eveque 5.45 1.00 4.21 77.2

Danablu 4.32 1.37 2.80 64.8

Blue 3.43 1.18 1.93 56.2

Camembert 1.27 0.30 0.82 64.6

Brie 1.66 0.39 1.02 61.5

Gruyere 1.11 0.52 0.72 65.0

Emmental 1.38 0.42 0.97 70.1

Gouda 1.00 0.14 0.90 90.2

Maribo 1.26 0.27 1.17 92.7

Cheddar 1.04 0.25 0.88 84.3

Edam 1.42 0.27 1.33 93.3

Parmesan 1.24 0.54 0.79 63.5

The B/A shows the rate of peptide of the adsorption to peptide in 70%Et-OH soluble fraction.

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成チーズは乳酸菌のみをスターターとして使用されていることから乳酸菌のプロテアーゼがペプチド生成に重要な役割を担うことが知られている．一方，白カビや青カビチーズは乳酸菌とカビがスターターとして使用されることから，乳酸菌プロテアーゼの他にカビ由来の酵素も関わりペプチドが生成される．したがって，白カビや青カビチーズにおいて乳酸菌チーズより親水性ペプチドの割合が高いことは，親水性ペプチドの生成にカビ由来酵素が関わっている可能性が推測された．

　２．Sep-Pak C18カートリッジにより分離された非吸　　着および吸着画分の抗酸化活性　カートリッジ非吸着および吸着両画分の抗酸化活性についてそれぞれ調べ，その結果を Table 2 に示した．非

熟成チーズであるモツアレラを除いた全てのチーズの両画分に活性が見出された．従って，各チーズには少なくとも SeP-PakC18カートリッジに吸着するものとしないものの２種類の抗酸化成分が存在することが推定された．また，吸着画分の方に比較的高い抗酸化活性が見出された．吸着画分において高い活性が認められたチーズは，ポンレベック（72. 7％），マンステール（70. 8％）ダナブルー（72. 5％）ブルー（75. 4％）で，リネンス菌熟成チーズと青カビ熟成チーズは70％以上の高い活性を示した．最も低かったのはチェダー（27. 1％），次いでパルメザン（34. 7％）であった．この結果は，既に報告（8）した70％ Et-OH可溶性画分を用いたときの抗酸化

活性の結果とほぼ同じであった．一方，非吸着画分において高い活性が認められたのは，吸着画分と同様にマンステール（58. 9％），ポンレベック（54 . 3％），ダナブルー（58. 4％）およびブルー（59 . 6％）で，青カビ熟成とリネンス菌熟成チーズは50％以上の高い活性であった．最も低かったのはブリー，次いでゴーダであり，これらの活性は40％以下であった．その他のチーズの抗酸化活性はいずれも40～50％であった．なお，非熟成チーズであるモツアレラは抗酸化活性が見い出せなかった．

３．Sep-PakC18カートリッジ分離両画分のペプチド量　　と抗酸化活性の相関　チーズのカートリッジ未吸着画分におけるペプチド量と抗酸化活性の相関性について調べ，その結果を Fig. 1に示した．モツアレラは近似線を大きく外れているが，

それ以外のチーズにおいては，若干の差はあるものの近似線から大きく外れているものはなかった．また両者の相関性は、回帰式：y＝24. 3938x+ 32. 0234で表せ，相関係数は r = 0. 7159（p< 0. 01）であった．このことから，カートリッジ非吸着画分におけるペプチドと抗酸化活性には，ほぼ直線的な相関性が認められ，ペプチドが多いチーズは高い抗酸化活性を有する可能性が示唆された．　次いで，チーズのカートリッジ吸着画分におけるペプチド量と抗酸化活性の相関性について調べ，その結果をFig. 2 に示した．非吸着画分と同様に，モツアレラは近似線を大きく外れているが，それ以外のチーズにおいては，若干の差はあるものの近似線から大きく外れているものはなかった．また両者の相関性は、回帰式：y＝11. 0033x+ 36. 5282で表せ，相関係数は r ＝0. 7371

Table 2　Antioxidative activity of Sep-Pack C18, non-adsorbed and adsorbed fraction

cheesAntioxidative Activity(%)

Non-AdsorbeFraction

AdsorbedFraction

Mozzarella 2.2 7.0

Munster 58.9 70.8

Pont-I’Eveque 54.3 72.7

Danablu 58.4 72.5

Blue 59.6 75.4

Camembert 40.3 63.5

Brie 36.9 62.0

Gruyere 45.0 44.3

Emmental 48.3 51.0

Gouda 39.5 41.2

Maribo 47.7 50.9

Cheddar 48.1 27.1

Edam 47.0 55.5

Parmesan 50.1 34.7

15

Fig. 1. Relationship between antioxidative activity and peptide contents in Sep-Pack C18 non-adsorbed fraction.

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チーズペプチドの Sep-PakC18カートリッジによる分離

（p< 0. 01）であった．このことから，カートリッジ吸着画分におけるペプチドと抗酸化活性にも，未吸着画分と同様にほぼ直線的な相関性が認められ，ペプチドの多いチーズが高い抗酸化活性を有する可能性が示唆された．以上の結果から Sep-PakC18カートリッジで分画された両画分の抗酸化活性をもたらす成分の一つとしてペプチドの可能性が考えられ，また熟成が進行したチーズに抗酸化活性の高い結果がみられた．

　これまでに，カゼイン分解物の抗酸化活性についていくつかの報告がなされている．Diaz et al.（12）は，カゼインホスホペプチド（CPP），カゼインタンパク質のトリプシン分解物（CH），およびカゼインタンパク質のトリプシン分解物を限外ろ過させた分子量10,000以下のカゼイン分解物（LMW CH）のリポソームの過酸化に対する抗酸化能を調べた．その結果，LMW CHは CPP

および CHよりも高い抗酸化能を示したことを報告している．また，Rival et al .（13，14）は，カゼインのトリプシン分解物がリポオキシゲナーゼやペルオキシラジカルによるリノール酸の過酸化を抑制したことを報告した．これらの報告は，活性測定法は異なるものの，チーズ中のカゼイン分解物ペプチドが抗酸化活性を有することを強く示唆するものであった．一方，工藤ら（10）はβカロテン退色法の抗酸化活性測定法によりκカゼイン由来ウンデカペプチドを発酵乳から見い出している．最近Gupta et al.（15）は熟成中のチェダーチーズの抗酸化活性を調べ，その活性はチーズの水溶性画分のペプチドの増加と一致していると述べている．また，Pritchard et

al.（16）はチェダーチーズ水溶性画分を分子量10,000以上と以下で分け，抗酸化活性は10,000以上の画分で最も高いと報告している．以上のことはチーズ中の抗酸化成

分の一つはカゼイン由来のペプチドであることを強く示唆した．

要　　約

　チーズ中のペプチドの性質や抗酸化活性を調べるために，市販チーズ14種類における70％エタノール可溶性画分中のペプチドを Sep-PakC18カートリッジにより非吸着と吸着画分に分離した．70％エタノール可溶性画分とSep-PakC18で分離した吸着画分のペプチド量を調べ，70％ Et-OH可溶性画分中のペプチドに占める吸着ペプチドの割合を算出した．その結果，マリボー，ゴーダ，エダムおよびチェダーの乳酸菌熟成チーズでは70％Et-OH可溶性画分の84％以上が吸着ペプチドであった．しかし，その他のチーズは80％以下で，特にカマンベールやブリーの白カビ，スチルトンやブルーの青カビ熟成チーズは50～60％で最も低かった．　分離された両画分のβ‒カロテン退色法による抗酸化活性を調べた．抗酸化活性は非吸着，吸着の両画分にいずれのチーズにおいても見出され，各チーズには少なくとも２種類の抗酸化成分，すなわち非吸着と吸着成分の存在が推定された．非吸着画分および吸着画分の抗酸化活性とペプチド量との相関関係についてそれぞれ調べた．その結果，比較的高い相関関係が両者に認められ，両画分の抗酸化活性成分はペプチドに起因する可能性が示唆された．

引用文献

１）農林水産省：牛乳・乳製品，チーズの需給表，　　 http: / / www. maff. go. jp/ j/ chikusan/ gyunyu/ lin/ index. html，２）Fox,P. F. , 1993, Cheese: An overview. in Cheese: Chemistry,

Physics and Microbiology （P. F. Fox, ed.）, Chapman＆Hall, London, pp. 1‒36.

３）大坂武男，1999，活性酸素，丸善，東京，pp. 3‒40．４）大澤俊彦，2002，日本農芸化学会誌，7 6 ，804‒813．５）仁木鋭雄，吉川敏一，大澤俊彦，1998，成人病予防

食品の開発，シーエムシー，東京 pp. 54‒65．６）Arai，S. , Osawa，T. , Ohigashi，H. , Yoshikawa，M. ,

Kaminokawa，S. , Watanabe，M. , Ogawa，T. , Okubo，K. , Watanabe，S. , Nishino，H. , Shinohara，K. , Esashi,

T. and Hirahara，T. , 2001，Biosci. Biotechnol. Biochem.，6 5 ，1‒13．

７）Osawa,T. , 1999, Mech. Aging& Dev.，1 1 1 ，133‒139.8）Igoshi,K. , Kondo,Y. , Kobayashi,H. , Kabata,K. and

Abstract 16

Fig. 2. Relationship between antioxidative activity and peptide contents in Sep-Pack C18 adsorbed fraction.

p07-12_kondo.indd 11 2015/02/26 11:38:40

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Kawakami, H. , 2008, Milchiwissenschaft, 6 3 , 424‒ 427.９）Lowry, O. H. , Rosebrough, N. , Farr, A. L. and Randall, R.

J. , 1951, J. Biol. Chem. , 1 9 3 ，265‒275.10）工藤康文，松田茂樹，井越敬司，沖智之，2001，日

本食品科学工学会誌，4 8 ，44‒50.11）中江　利孝，1982，世界のチーズ要覧，三洋出版，

東京 pp. 57‒75．　12）Daiz, M. and Decker, E. A. , 2004, J. Agric. Food Chem.，

5 2，8208‒8213.13）Rival，S. G. Fornaroli，S. , Boeriu，C. G. and Wichers,

H. J. , 2001, J. Agric. Food Chem.，4 9 ，287‒294.14）Rival，S. G. , Fornaroli，S. , Boeriu，C. G. and Wichers,

H. J. 2001, J. Agric. Food Chem.，4 9 ，295‒302.15）Gupta,A. , Mann,B. Sangwan, R. R. B. , 2009, Int. J.

Dairy Technol. , 6 2, 339‒347.16）Pritchard,S. R. , Phillips, M. and Kailasapathy, K. , 2010,

Food Res. Int. , 4 3 , 1545‒1548.

p07-12_kondo.indd 12 2015/02/26 11:38:40

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マコモの環境保全機能および機能性に関する研究東海大農紀要　34：13－17（2015）

水生バイオマス「マコモ」の環境保全機能および生産性・機能性に関する研究

仲川侑希 *・仁木博脩 *・長谷川大輔 **・橋本歩果 **・高橋智保 ** 川合祐加 **本田憲昭 ***・岡本智伸 **・増岡智加子 **・安田　伸 **・椛田聖孝 **

Studies on the Function of Environmental Preservation and

the Productivity of Aquatic Biomass ʻʻWild Riceʼʼ

Yuki NAKAGAWA, Hironobu NIKI, Daisuke HASEGAWA, Ayuka HASHIMOTO,

Chiho TAKAHASHI, Yuka KAWAI，Kensho HONDA, Chinobu OKAMOTO,

Chikako MASUOKA, Shin YASUDA and Kiyotaka KABATA

　In this research, it was aimed to explore the function of environmental preservation and productivity, functionality of wild

rice （Z iz ania latifolia） that is an a uatic plant belonging to ramineous. The influences on the soil by cultivation of wild rice

were examined for preservative function. t was suggested that the cultivation of wild rice influences on the total carbon of the

experimental field soil. bout productivity and functionality, three cultivars （Azumi, Ittenkou and Aogara） were compared. In

the result, it was suggested the yield of Azumi was the highest among the three cultivars in both edible part and stem and leaf

part. Functionality of wild rice was evaluated by analysis of anti oxidative function and anti allergic function and the highest

anti oxidative action of three cultivars was seen in stem and leaf part of Azumi. Furthermore, its value exceeded BHA which is

used as anti oxidant. The difference in anti allergic function was not seen in edible part and stem and leaf part of the three

cultivars. However, the values were higher than tranilast in all sample of wild rice. From these result, a further expansion of the

wild rice usage was suggested. It is necessary to clarify the depuration from both sides of the soil and the water quality.

緒　　言

　マコモ（Z iz ania latifolia）は植物分類学上，イネ科に属する多年性の水生植物である．中国，韓国，シベリア東部，インドシナ半島に至るまでの熱帯から寒帯に広く自生し，我が国でも全国的に分布している（１）．黒穂菌（Ustilago esculenta）の感染により肥大した茎部はマコモタケと呼ばれ，中国では夏野菜として料理に用いられる．マコモは水辺に生息し，河川や湖沼などで育つ．また，水田での栽培が容易であり，休耕田の有効活用といった観点からも期待できる．更に，マコモは様々な健康的機能を持つと言われている．その例として中国明代

に編集された本草綱目にマコモによる抗炎症作用，利尿作用などが記載されている．また，マコモ茎葉部における抗酸化作用なども報告されている（２）．しかし，品種間における生産性および機能性の差など，未解明な点が存在することも現状である．　一方，地球上において人口増加は深刻な問題であり，2050年までに90億人を超えると試算されている（３）．また，小麦，大豆，トウモロコシなどといった穀物の価格高騰が起こっている．このような情勢下で世界的な食糧不足が問題となることは明らかである．日本の食料自給率はカロリーベース当たり39%であり（４），今後起こり得る食料危機を考えると，とりわけ不安な状況である．　加えて，我が国の水質および土壌環境は，高度な経済成長に伴い，急速に富栄養化が進んでおり（５），これらによる農業への悪影響が懸念される．また，畜産にお

＊東海大学大学院農学研究科＊＊東海大学農学部＊＊＊東海大学農学教育実習場

（Received 19 November 2014; Accepted 19 December 2014）

p13-17_nakagawa.indd 13 2015/02/26 11:38:53

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仲川　侑希・仁木　博脩・長谷川　大輔・橋本　歩果・高橋　智保・川合　祐加本田　憲昭・岡本　智伸・増岡　智加子・安田　伸・椛田　聖孝

いては多頭飼育の環境に及ぼす影響が問題視されている（６）．今までに水質・土壌環境の改善策として浚渫，曝気，オゾンを利用した物理・化学的処理等が行われてきたが，高コストである上，持続的な改善が行えないという側面を持つ．そのため，低コストで持続可能な手段が望まれており，これまで水生植物を利用した生物的浄化に関する研究が行われてきた（７－10）．

　本研究では，品種別でマコモの生産効率および機能性を比較した．更に，土壌における浄化作用の検討を行い，総合的にマコモの持つ農産物としての付加価値を評価した．


材料　あずみ，一点紅，青殻といったマコモ３品種は学内にて栽培した．縦3. 5m，横12. 0mの水田に株分けした苗を各品種４か所ずつ植え付け，これを２区用意した．2013年5月27日に植付けを行い，2013年10月4日に各品種の可食部および茎葉部を収穫した．

マコモ栽培による土壌浄化作用の検討　土壌浄化作用については pH，総有機物含有量，全炭素含有量の測定から評価を行った．なお，本実験では１

区のみを用いた．まず，対照区および試験区に分割する前に，３か所からランダムサンプリング法により，土壌を採取した（2013年5月15日）．その後，Fig. 3 に示した通り，対照区，試験区をそれぞれ設置し，マコモ収穫前の2013年10月2日に土壌を採取した．この時も同様にランダムサンプリング法を用いた．採取した各土壌は攪拌後，室内にて常温で約１週間乾燥させ，移植ゴテなどを用いて細かく裁断した．更に，１mm以下のふるいにかけ，これを実験用サンプルとして用いた．

品種別での最大高推移および収量の比較　最大高推移，収量に関しては，１区に１品種当たり４株植え付けてあるため，それぞれ２区から計8株の平均を求めた．まず，最大高は6月から10月にかけて月に１度，計４回の測定を行った．収量においては，可食部および茎葉部の質量，可食部の収穫個数から，各品種における差を検討した．

マコモ各品種における可食部および茎葉部の機能性に関する検討　機能性においては抗酸化作用および抗アレルギー作用の検討を行った．マコモ各品種の可食部および茎葉部を収穫後，60℃で72時間の乾燥を行い，粉砕機にかけた．更に，それぞれ５gを80%メタノール100mlで抽出し，機能性試験のためのサンプルとして用いた．抗酸化作用においてはロダン鉄法を用いて検討を行った（11）．この時，比較対象として BHA，DL-α - トコフェロールに加え，高い抗酸化作用・抗アレルギー作用等が期待されるスイゼンジノリ（12），有機イグサ（岡山３号）を用いた（13）．抗アレルギー作用では，Davidsonらによるヒアルロニダーゼ活性阻害試験により検討を行った（14）．また，比較対象にはトラニラスト，DSCG，スイゼンジノリ，有機イグサを用いた．

Fig. 1. Cultivation experiment of wild rice　（Z iz ania latifolia） on the field of To ai niversity.

Fig. 3. Installation of experimental group and control group for soil remediation experiments.

Fig. 2. Edible parts of wild rice.

p13-17_nakagawa.indd 14 2015/02/26 11:38:53

─ 15 ─

マコモの環境保全機能および機能性に関する研究


　マコモ栽培による土壌の pH，総有機物含有量および全炭素含有量に及ぼす影響を検討した結果を Table 1に示した．本実験を通じて pH，総有機物含有量においては，マコモ栽培による影響は見らなかった．全炭素含有量に関しては，対照区と比較して，試験区に低い値が見られた．今後は，土壌だけでなく，溶存酸素，硝酸性窒素，アンモニア性窒素などを含めた水質における影響（15），品種における浄化作用の差などを検討していく必要がある．

Table 1. Examination of the depuration on soil by cultivation of wild rice.

2013/5/152013/10/2

Controlgroup

Experimental group

pH6.49

±0.086.37

±0.066.45

±0.08Total

organic matter（%）

33.71±0.21

29.20±0.16

30.15±0.07

Totalcarbon（%）

6.19±1.10

4.34±0.23

3.38±0.11

　各品種別で最大高推移を調査した結果を Fig. 4 に示した．7月の時点ではあずみに最も速い成長速度が見られたが，8月には一点紅および青殻が追いつき，最終的には品種間における大きな差は見られなかった．各品種の収量に関しては，Table 2 に示した通りの結果となった．可食部および茎葉部の収量，可食部収穫数の全てにおいてあずみが最も高い生産性を示す傾向にあった．このことから，本実験で用いたマコモ３品種のうち，あずみは阿蘇地域において高い生産効率を有することが示唆された．一方，可食部においては青殻の収穫量および収穫数

が最も低かった．しかし，茎葉部の収穫量を見てみると青殻は一点紅を上回った．茎葉部はこれまでにサイレージ原料（４），お茶（２）などとして用いられており，今後の更なる用途拡大が考えられる．このことを考慮すると青殻も有用品種の１つとして期待できる．

Table 2. The yield of wild rice on each cultivar.

Ediblepart

Stem and leafpart

NumberWeight（kg）

Weight（kg）

Azumi8.38

±2.621.41

±0.492.16

±0.73

Ittenkou4.63

±2.331.18

±0.451.24

±0.50

Aogara1.88

±2.590.57

±0.731.91

±0.44

　ロダン鉄法により各サンプルの抗酸化作用を評価した結果は，Fig. 5 に示した通りとなった．まず，マコモ各品種の可食部および茎葉部で比較してみると，全ての品種において茎葉部に可食部を上回る抗酸化作用が見られた．その中でも特に，あずみ茎葉部に高い活性が観察された．また，あずみ茎葉部の抗酸化作用は，有機イグサやスイゼンジノリには劣るが，酸化防止剤として用いられる BHAを上回った．Fig. 6 に示したヒアルロニダーゼ活性阻害試験による抗アレルギー作用の評価を行った結果からは，誤差が大きく，各品種の可食部および茎葉部における差は見られなかった．また，こちらでも，マコモ全てのサンプルにおいて有機イグサやスイゼンジノリには劣るものの，医薬品として知られるトラニラストを超える抗アレルギー作用が観察された．しかし，全体的に誤差が大きく，繰り返し検討する必要がある．また，抗酸化作用においても現在主流の ORAC法などを用いて，ロダン鉄法と同様の傾向が見られるか確認することも今後の課題である．

量を見てみるとはを回った．茎葉

部はこれまでにイー（），お（）

などとして用いられてお，今後のなる用途拡

大がえられる．このことをするとも有

用品種の 1 として期待でる．

Fig．4．The maximum height of wild rice on each cultivar.

Table 2．The yield of wild rice on each cultivar.

Edible

part

Stem and leaf

part

Number Weight

(kg)

Weight

（kg）

Azumi 8.38

±2.62

1.41

±0.49

2.16

±0.73

Ittenkou 4.63

±2.33

1.18

±0.45

1.24

±0.50

Aogara 1.88

±2.59

0.57

±0.73

1.91

±0.44

によの抗酸化作用を

価した結果は，Fig．5 に示したとなった．ま

ず，マコモ品種の可食部および茎葉部でし

てみると，全ての品種において茎葉部に可食部を

回る抗酸化作用が見られた．の中でもに，

あずみ茎葉部に高い性がされた．また，あ

ずみ茎葉部の抗酸化作用は，有機イイ

にはるが，酸化として用いられ

る BHA を回った．Fig．6 に示した

ー性試験による抗ー作用の

価を行った結果からは，が大，品種の

可食部および茎葉部におけるは見られなかった．

また，こらでも，マコモ全てのにおい

て有機イイにはるものの，

品としてられるを超える抗

ー作用がされた．しかし，全に

が大，し検討する必要がある．また，

抗酸化作用においても現在の ORAC などを

用いて，とのが見られるか

認することも今後のである．

0

50

100

150

200

250

2013/6/4 2013/7/4 2013/8/5 2013/9/4 2013/10/2

cm

Azumi

Ittenkou

Aogara

Fig. ₄.The maximum height of wild rice on each cultivar.

Azumi

Ittenkou

Aogara

250

200

150

100

50

0

cm

2013/ 6/ 4 2013/ 7/ 4 2013/ 8/ 5 2013/ 9/ 4 2013/ 10/ 2

p13-17_nakagawa.indd 15 2015/02/26 11:38:54

─ 16 ─

仲川　侑希・仁木　博脩・長谷川　大輔・橋本　歩果・高橋　智保・川合　祐加本田　憲昭・岡本　智伸・増岡　智加子・安田　伸・椛田　聖孝

　阿蘇地域における栽培試験，機能性試験の結果，今回検討を行ったマコモ３品種の中であずみが最も有用な品種であることが示唆された．また，マコモ茎葉部に可食部を超える抗酸化作用が見られ，今後の用途拡大が期待される．マコモ栽培が及ぼす環境保全機能に関しては，本実験では土壌における pH，総有機物含有量への影響は見られなかった．しかしながら，水質浄化に関するデータ（未発表）においては，浄化能が認められ，現在，詳細な分析を継続中である．今後は，土壌，水質両者におけるマコモの保全機能および可食部の更なる付加価値を検討する必要がある．

要　　約

　本研究では，イネ科に属する多年性水生植物であるマコモ（ Z iz ania latifolia）の環境保全機能および生産性・

機能性に関する研究を行った．環境保全機能に関しては，マコモ栽培による土壌への影響を検討した．土壌中全炭素においてはマコモによる影響が示唆されたが，pHおよび総有機物には差が見られなかった．生産性に関しては，今回比較を行ったあずみ，一点紅，青殻の3品種のうち，可食部，茎葉部の双方にてあずみに阿蘇地域で多収性を示す傾向が見られた．機能性においても3品種のうち，あずみに最も高い抗酸化作用が見られた．また，可食部と比較して茎葉部の活性が高く，酸化防止剤として知られる BHAを上回る値を示し，用途拡大が期待される．抗アレルギー作用においてはマコモ各品種の可食部および茎葉部で，医薬品として用いられるトラニラストを超える効果が見られた．今後は，マコモ栽培時における環境への影響について，水質を含めた多面的方向からの作用機作の解明および生産物の活用を進展させる必要がある．

Fig．5．Anti oxidative activity of the each 80% methanol extracts. The final concentration of each

sample tested was 0.02% (v/v). The value of the ethnol control represents 100% lipid peroxidation.

Fig．6．Inhibitory effect of the each 80% methanol extract on the activation of hyaluronidase.

阿蘇地域における栽培試験，機能性試験の結果，

今回検討を行ったマコモ 3 品種の中であずみが最

も有用な品種であることが示唆された．また，マ

コモ茎葉部に可食部を超える抗酸化作用が見られ，

今後の用途拡大が期待される．マコモ栽培が及ぼ

す環境保全機能に関しては，本実験では土壌にお

ける pH，総有機物含有量への影響は見られなかっ

た．しかしながら，水質浄化に関するデータ（未

発表）においては，浄化能が認められ，現在，詳

細な分析を継続中である．今後は，土壌，水質両

者におけるマコモの保全機能に関する作用機作お

よび可食部の付加価値を高める検討などが必要で

ある．

要約

本研究では，イネ科に属する多年性水生植物で

0 20 40 60 80 100

ControlBHA

DL-α-tocopherolSuizenjinori

Organic rushAogara (stem and leaf part)

Aogara (edible part)Ittenkou (stem and leaf part)

Ittenkou (edible part)Azumi (stem and leaf part)

Azumi (edible part)

Anti oxidative activity (%)

0 20 40 60 80 100

TranilastDSCG

SuizenjinoriOrganic rush

Aogara (stem and leaf part)Aogara (edible part)

Ittenkou (stem and leaf part)Ittenkou (edible part)

Azumi (stem and leaf part)Azumi (edible part)

Inhibition rate on the activation of hyaluronidase (%)

Fig. 5. Anti oxidative activity of the each ₈₀ methanol extracts. The final concentration of each sample tested was ₀. ₀2% (v/ v). The value of the ethnol control represents ₁₀₀% lipid peroxidation.

Fig．5．Anti oxidative activity of the each 80% methanol extracts. The final concentration of each

sample tested was 0.02% (v/v). The value of the ethnol control represents 100% lipid peroxidation.

Fig．6．Inhibitory effect of the each 80% methanol extract on the activation of hyaluronidase.

阿蘇地域における栽培試験，機能性試験の結果，

今回検討を行ったマコモ 3 品種の中であずみが最

も有用な品種であることが示唆された．また，マ

コモ茎葉部に可食部を超える抗酸化作用が見られ，

今後の用途拡大が期待される．マコモ栽培が及ぼ

す環境保全機能に関しては，本実験では土壌にお

ける pH，総有機物含有量への影響は見られなかっ

た．しかしながら，水質浄化に関するデータ（未

発表）においては，浄化能が認められ，現在，詳

細な分析を継続中である．今後は，土壌，水質両

者におけるマコモの保全機能に関する作用機作お

よび可食部の付加価値を高める検討などが必要で

ある．

要約

本研究では，イネ科に属する多年性水生植物で

0 20 40 60 80 100

ControlBHA

DL-α-tocopherolSuizenjinori

Organic rushAogara (stem and leaf part)

Aogara (edible part)Ittenkou (stem and leaf part)

Ittenkou (edible part)Azumi (stem and leaf part)

Azumi (edible part)

Anti oxidative activity (%)

0 20 40 60 80 100

TranilastDSCG

SuizenjinoriOrganic rush

Aogara (stem and leaf part)Aogara (edible part)

Ittenkou (stem and leaf part)Ittenkou (edible part)

Azumi (stem and leaf part)Azumi (edible part)

Inhibition rate on the activation of hyaluronidase (%)Fig. ₆. Inhibitory effect of the each ₈₀% methanol extract on the activation of hyaluronidase.

p13-17_nakagawa.indd 16 2015/02/26 11:38:54

─ 17 ─

マコモの環境保全機能および機能性に関する研究

謝　　辞

　本研究を遂行するにあたり，多くのご協力を頂いた本学付属農場および，生物資源科学研究室の皆様に心より感謝の念を捧げます．

引用文献

１）中村重正，2000，菌食の民俗誌－マコモと黒穂菌の利用－，株式会社八坂書房，東京，19‒21

２）西嶋政和，2014，マコモタケ－導入と高品質・多収栽培－，一般財団法人農山漁村文化協会，東京，131‒134

３）総務省統計局，2009，世界の統計2009，総務　　省統計研修所，東京，26４）服部信司，2011，TPP問題と日本農業，財団法人

農林統計協会，東京，17‒19５）清水正元，1988，江津湖，3，11‒28６）梶田真祥，2009，資源循環型・水環境改善対策およ

び生物多様性に関する研究，東海大学大学院平成21年度修士論文，1‒3

７）環境庁水質保全局，1986，湖沼の水質保全，株式会社地球社，東京，20‒31

8）財団法人日本植物調節剤研究会，1973，新版日本原色雑草図鑑，株式会社全国農村教育協会，東京，90‒281

９）辻盛正，宮坂均，奥畑博史，山田一裕，平塚明，2008，日本緑化工学会，34（1），241‒244

10）Montien-art, B.，Nakazono, T.，Okamoto, C.，Odahara,

T.，Kikuchi, M. and Kabata, K.，1998，Grassland

Science，44，151‒12111）内平倫義，内藤信二，増岡智加子，岡本智伸，山下

秀次，井越敬司，小野政輝，椛田聖孝，2013，東海大農紀要，32，8

12）椛田聖孝，金子達雄，2008，新発見「サクラン」と伝統のスイゼンジノリ，株式会社ハート出版，東京，43‒46

13）安田伸，山本貴大，佐伯真菜美，小野政輝，井越敬司，椛田聖孝，2013，東海大農紀要，32，13‒18

14）椛田聖孝，岡本智伸，笹田直繁，小野政輝，井越敬司，小林弘昌，増岡智加子，伊東保之，2005，九州東海大農紀要，24，38

15）工藤匡平，梶田真祥，浜田俊雄，小池晶琴，岡本智伸，椛田聖孝，2011，東海大農紀要，30，1‒6

　　

　　

p13-17_nakagawa.indd 17 2015/02/26 11:38:54

─ 19 ─

English Ability and the Tourism Industry in Siem Reap, Cambodia東海大農紀要　34：19－29（2015）

English Ability and the Tourism Industryin Siem Reap, Cambodia

Jeffrey Stewart Morrow

1 . 　Introduction

　　Since the end of the 1970ʼs, three factors have become

important for economic development in Cambodia: 1） aid

agency involvement, 2） trade, and 3） tourism. Aid agency

involvement in the rebuilding of ambodia after the horrific

events of dictator Pol Pot1 was first responsible for solidifying

the need for English during development. In 1982, trade was

boosted to assist with development efforts; textiles, rubber,

footwear became main export items mainly to the U. S.

（Economy Watch, 2010）. The tourism industry blossomed in

the early part of 2000 after Angkor Wat became a World

Heritage Site in 1992 . These three factors advanced English

proficiency needs for employment in development, especially

the tourism industry.

　　Most visitors go to Cambodia to engage in tourism, and

therefore need English for tourism activities. Many visitors

are from inner circle2 countries where English is used as a

main language; however, one could also assume that visitors

from outer circle countries use English during tourist

activities, as it is a world language. Even in cases of business

or official travel in ambodia, it can be assumed that English

would be most commonly used as the tool of communication,

as at present there are 510 million total native and non-native

English speakers worldwide （V istawide, 2010）. 　　English is important not only in the tourism industry, but

also in aid agencies and trade and industry which are backed

by foreign direct investment （FDI） and official development

assistance （ODA）. The Cambodian society and economy

have been forging international relations since the downfall

after Pol Pot. International relations are comprised of three

components: 1） political relations, 2） international social

relations, and 3） international economic relations. It is the

goal of this paper to show that English has a large

socioeconomic effect on the lives of Cambodians. The paper

attempts to verify the importance of English in economic

aspects, especially employment and income.

　　To that end, this paper will explore the role of English in

employment and income in the tourism industry, through the

examination of employment, income, and English proficiency

of the tourism industry labor force in Siem Reap. The method

used in the survey was to gather information on items such as

years of general schooling, years of English education, and

usage of English per month in the tourism industry, among

要旨　カンボジアにおける1990年代後半からの観光事業の増加により，シアムリアップとプノンペンでは，外国語（特に英語）の訓練を受けた事業従事者の需要が高まっている．これまでに，センサスデータを使った自己申告型の英語能力と収入の関係は研究されてきたが，対象者の具体的な英語能力の評価は困難であった．そこで筆者はCommon European Frame of Reference for Languages （CEFR）, Council of Europe, 2001を基本とする新しい英語能力評価法を考案し，2010年にシアムリアップにて，観光事業の主要５部門ににおける雇用者の英語能力と収入を評価した．その結果，英語能力は雇用と収入に大きく寄与することが分かった．

（Received 20 September 2014; Accepted 8 October 2014）

Tokai University１　Pol Pot will be discussed in section 2.２　Kachru ( 1985 defines “inner circle” countries as those where English is spoken as the native language. “Outer circle” countries

are those where English is sometimes an official language or a lingua franca and is often used as the language of business or politics.

p19-29_Morrow.indd 19 2015/02/26 11:39:04

─ 20 ─


others, and to correlate these items statistically with various

measures. In section 2, the paper will explain Pol Pot and

review agency involvement. Section 3 explores trade/ FDI

aspects, and section 4 examines tourism data of Cambodia.

Section 5 explains the survey background, section 6 describes

the method and location, and section 7 explains the sample.

In section 8 the survey results are analyzed, and section 9 offers concluding remarks. Section 10 includes implications

for future research.

　

2. 　Involvement of Aid Agencies in the Rebuilding of Cambodia　　In 1975, ruthless dictator Pol Pot, leading the Khmer

Rouge, overthrew the then president Lon Nol, in the hopes of

making Cambodia an agrarian utopia. Millions of citizens,

including lawyers, doctors, academics, families, and students

were forced to evacuate their homes and were sent to

agriculture camps in rural Cambodia. Many of the people

executed under Pol Pot had English ability and could work in

tourism or in foreign companies. Money lost its value,

religion was banned, books and data were burned. The year

became known as “year zero,” and was one of the darkest

periods in the history of Cambodia. After Pol Pot was ousted

and Cambodiaʼs diplomatic relations became normalized,

tourists flooded to Cambodia and communicated in English

whatever their nationalities . Table 1 describes the

chronological events of the Pol Pot/ Khmer Rouge regime.

In the years since the Pol Pot regime, in effort to rebuild

the nation Cambodia has accepted monetary aid from four

different types of aid agencies: 1） bilateral, 2） multilateral, 3） international and regional financial institutions, and 4） non-

governmental organizations as outlined in Table 2 . With

millions of US dollars being invested in the country through

English speaking aid agencies, they are an integral part of

continued development. Even though the aid agencies listed

in the Table are from countries such as Japan, Netherlands,

Norway, Belgium, Switzerland and France, English is used as

the main language of operations. In addition, aid agencies

employ Cambodians to work in many areas, such as office

staff and related jobs. Data from Clayton （2006） show that

possibly as many as 21,850 Cambodians worked directly with

aid agencies. In addition Clayton （2000） found that, without

question, English was the preferred language among aid

agencies. Hence, many of the connected jobs require English

ability to obtain employment （Clayton 2006）.

3 . 　Trade

　　In 1982, the Cambodian government made serious efforts

Table 1. Chronological Events Surrounding Pol Pot

Year Event

1953 Cambodia won independence from France. It became the Kingdom of Cambodia under King Sihanouk.

1960 Norodom Sihanouk became head of state of Cambodia after the death of his father, King Sihanouk.

1969Sihanouk broke away from U.S. and allowed North Vietnam to base itself in Cambodia to �ght against U.S. backed South Vietnam.

1970Prime minister Lon Nol overthrew Sihanouk in a coup, organized the Khmer Rebublic, and sent soldiers to �ght the North Vietnamese.

1975 Lon Nol was overthrown by the Khmer Rouge, led by Pol Pot, and soon overtook Phnom Penh.

1976 Democratic Kampuchea was formed. Pol Pot became prime minister.

1977 Fighting began with Vietnam.

1978 Vietnam invaded Cambodia.

1979Vietnam overtook Phnom Penh, Pol Pot and the Khmer Rouge escaped to the Thai border, and the People's Republic of Kampuchea was established.

1981The Kampuchean People's Revolutionary Party was elected into power, but it was unrecognized by international communities.

1985 Hun Sen became prime minister of Cambodia, but guerilla warfare continued.

1989 Vietnamese army withdrew from Cambodia. Socialism was abolished. The country was renamed Cambodia.

Source: BBC News, Asia-Paci�c, Cambodia pro�le, "a chronology of key events," （November 6, 2012）http www.bbc.co.uk news world asia paci c January 5, 2013

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English Ability and the Tourism Industry in Siem Reap, Cambodia

to make trade a catalyst of economic development; however,

at first trade was established to keep the economy balanced

and as as result no export figures or official records were ept.

In the absence of records, the U. S. set the trade deficit at

between US $ 100 and US $ 200 million between 1981 and

1987 （Photius, 1987）. In 2008, trade export value reached

US $ 4 . 707 billion （Economy Watch, 2008）. Trade partners

and export percentages, in Table 3, show that the U. S. which

uses English exclusively, is the biggest export partner with a

55% share. Not all the countries in partnership are inner

circle countries, but many trade partnership countries use

English in trade negotiations. Trade requires communication

more than industry or business because of the need for

bargaining ability.

　　In addition to trade, Foreign Direct Investment （FDI） has

also made a large contribution to the economy of Cambodia

during development after Pol Pot. Over US $ 5 billion has

been invested in Cambodia nationwide through FDI in the

hotel/ restaurant, textile, and apparel, industries. Growth of

FDI means growth of business, but not only in terms of

capital. It also means the growth of the flow of people

required to use English to earn their living. FDI in hotels and

restaurants allowed expansion of many 3 to 5 star hotels, and

of course, bolstered the employment market in all related jobs

such as wait staff, concierges, receptionists, and hosts. FDI in

textile and apparel was nearly US $ 7 million between 1994 and 2004 in Phnom Penh and Sihanoukville, and these

became large export commodities. This is most likely due to

Cambodia being granted Most Favored Nation （MFN） status,

and becoming a trade beneficiary of Generalized System of

Preferences （GSP） by the US and European nations. Almost

all exports of garments/ apparel during this period were to the

US and Canada, requiring communication in English. Table 4 illustrates FDI within Cambodia between 1994 and 2004.

4 . 　Tourism

International tourism has increased rapidly in and around

Indochina since the end of the 1990ʼs. Cambodia has become

a backpacker destination of choice after Angkor Wat became a

World Heritage Site in 1992. Tourism receipts for Cambodia

Table 2. Aid Agencies and Aid Disbursement in Cambodia, 1992‒2001

Type of Agency Examples of Participating AgenciesParticipating Countries and Aid Amount （in US$ million）Total Aid = US $4.2 billion

Bilateral （given bywealthy, developednations to poorer）

Japan International Cooperation Agency （JICA）,the United States Agency for International Development, the Australian Agency for International Development, the Swedish International Development Cooperation Agency.

Japan （US $913）, France （US $311）, U.S. （US $300）, Sweden （US $145）

Aid amount = US $2.4 billion（58% of total）

Multi-Lateral（nations involved with globaldevelopmentagencies）

United Nations Development Programme （UNDP）, United Nations Children's Fund （UNICEF）, the United Nations Eduational, Scienti�c, and Cultural Organization （UNESCO）, World Health Organization （WHO）, European Union, and

United States, Japan, Netherlands,Norway, Sweden, Belgium, Canada,France, United Kingdom

Aid amount = US $695 （17% of total）

International andRegional Finance Institutions（banking）

International Monetary Fund （IMF）, WorldBank （WB）, Asian Development Bank （ADB）

United States, France, United Kingdom


Non-Governmental Organizations （NGOʼs）

Church Wood Service, Concern, Doctorswithout Borders, Dan Church Aid, International Volunteers of Yamaguchi

United States, Ireland, France, Denmark,Switzerland, Japan


Source: Council for the Development of Cambodia, in Clayton, 2006

Table 3. Trade Export Partners and Export Commodities from Cambodia, 2008

Examples of Trade Partners andPercent of Exports （in %）

Examples of Export Commodities

The U. S. 54. 5, Germany 7. 7,Canada 5. 9, The U. K. 5. 5V ietnam 4. 5

Clothing, Timber, Rubber, Rice,Fish, Tobacco, Footwear

Source: Economy Watch, 2008

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show an increase from US $ 228 million in 2000 to just over

US $ 1. 5 billion in 2009. The number of total visitors number

increased from 367,743 in 1999 to 2,161,577 in 2009 （see

Table 5）.

　　Tourism accounts for 10 % of global GDP （WTTC, 2003 in Ennew, 2003）. In many countries in the Caribbean area as

well as Egypt, GDP increase and economic impact from

tourism have been significant and for other countries like

Cambodia, tourism will be a major source of revenue for

continued economic growth in the future （Ennew, 2003）. Table 5 shows that in 2010, international visitors to Cambodia

reached 2,508,289 up from 2,161,577 in 2009, an increase of

13%. This is quite an increase considering the fact that the

world was suffering from economic crisis （Cambodia

Ministry of Tourism, 2010）. Compared to 1999, which had a

total of 367,743 tourists, the number of tourists increased

about 7 times to 2,508,289 in 2010. The contribution to GDP

from tourism receipts in 2010 was US $ 1. 7 million. Tourism

has been continually the largest contributor to service sector

growth, with hotel occupancy rates at nearly 65% in 2010 （Cambodia Ministry of Tourism, 2010）. Fig. 1 shows the list

of the top seven tourist arrivals to Cambodia in 2010. The top

four were Asian countries: V ietnam, Korea, China, and Japan;

fifth was the .S. . and seventh was the . . the . . and

U. S. A. are both inner circle countries.

　　Even though Asian countries top the list of international

visitors in 2009-10, English as an international language in

most likely used by these groups for communication.

Yoneoka （2009） who has done extensive research on

language needs of East-Asian tourism, found that among

China, Japan, and Korea, English as an International

Language （EIL） is widely needed, especially in tourism

businesses. Fig. 1 shows that these are the exact nationalities

that visited Cambodia in 2009-10 and used EIL in travel,

although French visitors may have also used French as

Cambodia was once a French colony.

　　As for employment in tourism, data from the Economic

Institute of Cambodia in Table 6 display the percentage of

Table 4. Comparison of Approved and Actual FDI, 1994‒2004 （in US$ 1,000）*

Province textile apparel hotels and restaurants

Approved Actual Approved Actual Approved Actual

Phnom Penh 66877 17201 888690 644663 784660 270954

Sihoukville 29903 29903 29864 19614 184 0

Siem Reap 0 0 0 0 107317 90354

Total 96780 47104 918554 664277 892161 361308

Source: Compiled from Cuyvers, 2011 *Given as lump sum contribution between 1994 and 2004

Table 5. Cambodia V isitor Arrivals, 1999‒2010.

YearTotal Number of Tourists

Percent ofChange

Average Lengthof Stay （days）

HotelOccupancy（%）

Tourism Receipts（$US million）

1999 367,743 27.02 5.50 44.00 190

2000 466,365 26.82 5.50 45.00 228

2001 604,919 29.71 5.50 48.00 304

2002 786,524 30.02 5.80 50.00 379

2003 701,014 －10.87 5.50 50.00 347

2004 1,055,202 50.53 6.30 52.00 578

2005 1,421,615 34.72 6.30 52.00 832

2006 1,700,041 19.59 6.50 54.79 1,049

2007 2,015,128 18.53 6.50 54.79 1,400

2008 2,125,465 5.48 6.65 62.68 1,595

2009 2,161,577 1.70 6.45 63.57 1,561

2010 2,508,289 16.04 6.45 65.74 1,786

Source: Cambodia Ministry of Tourism, 2010

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working age population （ages 15-64） per sector in 2004 and

2007 . I t is evident that the services sector, which

encompasses tourism, ranks second among the employed

working age population at almost 22 percent, and this has

changed little between 2004 and 2007 （see Table 6）. Current

data show that, as of 2010, 29 . 6% of the working age

population is employed in services （National Institute of

Statistics, 2010）. Many industry and service sector

businesses are operated by foreign owners who can speak

English well and as such, those working in industry/ services

need and use EIL regularly.

5 . 　Survey of E mployment and E nglish

In August, 2010 the author conducted a survey involving

the tourism industry in Siem Reap, Cambodia to examine

employment opportunities with English. Siem Reap was

chosen as the survey locale for its proximity to Angkor Wat, a

typical cultural tourism destination. As such, it attracts

visitors from around the world annually, and many of them

are from inner circle countries or use EIL in travel. During

earlier travel experience there in the early part of 2000ʼs, the

author found that English communication was difficult for

tour guides and realized that this could be improved. In

addition, Cambodia as a developing country has very little

data on English education and its contribution to per capita

income, which lends itself to more research in the future.

The survey was conducted with the help of five English

speaking students with advanced English proficiency from

Angkor University in Siem Reap. It contained 50 questions

such as gender, living situation, marital status, years of

schooling, years of English education, frequency of English

speaking visitors per month, and rate of English usage per

month. To glean English proficiency, the author designed a

assessment which was loosely based on the Common

European Framework of References for Languages （Table 7）.

The CEFR measures English on a six level scale and is

adaptable to any language. The authorʼs measurement system

is clearly different from that of the CEFR. The CEFR contains

distinct, easily defined levels and the author emulated this

feature but adapted it to be more useful in the context of

Cambodia where many people have little or no English ability.

The author included assessment in levels to assess

quantifiably. By using level 0 （no ability） to 5 （greatest

ability）, proficiency is easily categori ed and easy to analy e

numerically （Table 8）. In this manner, it is very useful to

explain English proficiency and to lin with types of jobs and

job hunting. The assistants determined the spoken English

proficiency of each respondent during the interviews by

following the authorʼs criteria.

Figure 1 . International Tourist Arrivals, 20 0 9 - 20 1 0

Source: Cambodia Ministry of Tourism, 2 0 1 0

Even though Asian countries top the list of international visitors in 2009 -1 0 , English as

an international language in most likely used by these groups for communication. Yoneoka

( 200 9) who has done extensive research on language needs of East-Asian tourism, found that

among China, Japan, and Korea, English as an International Language ( EIL) is widely needed,

especially in tourism businesses. Fig. 1 shows that these are the exact nationalities that visited

Cambodia in 2009 -1 0 and used EIL in travel, although French visitors may have also used

French as Cambodia was once a French colony.

As for employment in tourism, data from the Economic Institute of Cambodia in Table 6

display the percentage of working age population ( ages 1 5 -6 4 ) per sector in 2004 and 2007 . It is

evident that the services sector, which encompasses tourism, ranks second among the employed

working age population at almost 22 percent, and this has changed little between 2004 and 2007

( see Table 5 ) . Current data show that, as of 2 010, 29.6% of the working age population is

employed in services ( National Institute of Statistics, 2 0 1 0 ) . Many industry and service sector

businesses are operated by foreign owners who can speak English well and as such, those

working in industry/ services need and use EIL regularly.

7

Figure 1. International Tourist Arrivals, 2009 - 2010

Table 6. Percent Employed of Working Age Population 2004 and 2007

Industry 2004 2007 Change

Agriculture 46.5% 46.7% 0.2%

Industry 10.9% 11.8% 1.9%

Services 21.7% 21.8% 0.1%

Total 79.1% 80.3% 1.2%

Source: Economic Institute of Cambodia 2008

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6 . 　Survey Method and Location

　　To conduct this study, the author employed a simple

stratified random survey in face to face interview format. The

sample strata were 184 members of the tourist industry labor

force in five tourist industries: souvenir/ shops; restaurants;

guest houses; hotels; and travel agencies. The survey was

conducted in Siem Reap City, Cambodia, from August 27‒31, 2010. The subjects were interviewed directly at their places of

work after receiving permission from the establishment.

Fortunately, regulations are not strict in Cambodia, and

permission was received relatively easily.

　　Souvenir shops were located in Old Market and around

the immediate area, restaurants were located on Pub Street

and Pub Street Alley, guest houses were located on Street 2, Street 3, Oum Khun Street, and across the bridge （street name

unknown）, travel/ agencies were located on Oum Khun Street

and Street 5, and Sivath Boulevard, and hotels were located

on National Road 6, and Angkor Wat Road （see Figure 2）.

Table 7. CEFR Reference Levels

A1 Breakthrough or beginner - can understand familiar everyday expressions, can introduce self

A2 Waystage or elementary - can understand and use expressions within immediate relevance

B1 Threshold or pre-intermediate - can understand main points and deal with traveling

B2 Vantage or intermediate - can understand and produce ideas on concrete and abstract topics

C1 Effective operational pro�ciency - can get implicit meaning, can use language �exibly

C2 Mastery or advanced - can understand everything, can express spontaneously and �uently

Source: Council of Europe for Language Education, 2001

Table 8. The Authorʼs English Assessment

0 No or little ability - canʼt communicate at all

1 Low Beginner - can only understand and use familiar everyday expressions

2 High Beginner - can understand and use expressions within everyday relevance

3 Low Intermediate - can understand many things, can produce but with many mistakes

4 High Intermediate - can understand and produce ideas but with lower con�dence

5 Advanced - can understand everything and produce �uently and con�dently

（Source: Author, 2010）

Figure 2. Map of Siem Reap City

N a t i o n a l R o a d 6

PokamborAvenue

SiemReap River

SivathaBoulevard

WatBo Road

O u m K h u n S t r e e t

S t r e e t 2

S t r e e t 3

R o y a l P a l a c e

S o u v e n i r S h o p s

R e s t a u r a n t s

G u e s t H o u s e s

T r a v e l A g e n c i e s

H o t e l s

S t r e e t 5

( a n d w i t h i n O l d M a r k e t )

Source: Created from survey data, 2 0 1 0

7. Sample

The sample size was determined after obtaining preliminary data as to total number of

shops in our survey bracket within Siem Reap City. After calculation, the sample size was

broken down in Table 9. There was no data from the city on actual number of souvenir shops,

which required the author to manually count and tabulate the total number. To achieve

randomness, each business was assigned a number, which was drawn blindly.

Table 9 . Sample, 20 1 0

E stablishment Total number of shops Sample Size Souvenir shops 3 0 0 ( after tabulation) 7 4 Restaurants 1 2 0 3 4 G uest houses 2 2 7 ( 3 ,0 0 0 rooms) 2 1 H otels 1 2 0 ( 8 ,7 2 3 rooms) 3 8 Travel Agencies 1 4 2 1 7 Source: Department of Tourism, Siem Reap. Adapted by the author, 2 0 1 0

10

Figure 2. Map of Siem Reap City

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7 . Sample

The sample size was determined after obtaining

preliminary data as to total number of shops in our survey

bracket within Siem Reap City. After calculation, the sample

size was broken down in Table 9. There was no data from the

city on actual number of souvenir shops, which required the

author to manually count and tabulate the total number. To

achieve randomness, each business was assigned a number,

which was drawn blindly.

8 . 　Analysis

　　The general results in Table 10 show that the majority of

the tourist industry labor force was in the 20-year age group.

This means that there is good potential to develop job skills

through English. Many older members of society were

executed during the Pol Pot regime, and therefore there were

fewer at age 40 and over, creating a skewed population. This

is consistent with other data （Ministry of Planning 2010）

which found a similar skew in other research. According to

this survey, the tourism industry was dominated by those in

their 20ʼs who depend on it for their livelihoods. In addition,

most respondents are from Siem Reap, most are single, have

no children, and live with families members. Survey findings

also show more females employed in tourism, with the

exception of hotels and travel agencies, which have more

males working.

Fig. 3 illustrates that English is indeed necessary due to the

influx of English speaking visitors; 85 % of the labor force

Table 9. Sample, 2010

Establishment Total number of shops Sample Size

Souvenir shops 300 （after tabulation） 74

Restaurants 120 34

Guest houses 227 （3,000 rooms） 21

Hotels 120 （8,723 rooms） 38

Travel Agencies 142 17

Source: Department of Tourism, Siem Reap. Adapted by the author, 2010

Table 10. General Information of Tourism Labor Force （in number of people）, Siem Reap, 2010

Item Souv/Ret. Rest. Guest Hse. Hotels Trav/Tour

Age 10‒19 18 2 3 2 0

20‒29 45 31 17 30 15

30-39 8 1 1 6 1

40 3 0 0 0 1

Total 74 34 21 38 17

Sex M 23 15 8 26 10

F 51 19 13 12 7

Total 74 34 21 38 17

Province Siem Reap 44 24 13 17 12

Phnom Pn 5 0 3 4 0

Other 25 10 5 17 5

Total 74 34 21 38 17

Marital Married 23 4 4 9 1

Single 51 30 17 29 16

Total 74 34 21 38 17

Children Yes 19 3 4 7 1

No 55 31 17 31 16

Total 74 34 21 38 17

Living Alone 14 12 5 15 6

W/Family 60 22 16 23 11

Dormitory 0 0 0 0 0

Other 0 0 0 0 0

Total 74 34 21 38 17

Source: Compiled from survey data, 2010

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Table 11. Correlation Results of Income and English Level

Business orrelation oefficientSouvenir 0. 09Restaurants 0. 15Guest Houses 0. 52Hotels 0. 29Travel Agencies ‒0. 03

Source: Calculated using survey data, 2010

stated that native English speaking tourists, EIL speakers, and

other Cambodians visit their establishments every day. The

fact that both native English speakers and EIL speakers visit

daily shows that English is absolutely needed daily for work

in the tourism industry in Siem Reap.

The frequency of English speaking tourists and use of EIL

h a s m a d e E n g l i s h a j o b

requirement as seen in the

photo in Fig. 4 ; the ability to

communicate in English is

essential in most jobs, even

entry level . Respondents

reported that their salaries

were higher than previously

and were elevated with English

proficiency. In this survey,

E n g l i s h p r o f i c i e n c y a n d

income connection was analyzed

both socially and numerically. The social survey question on

salary was not based on exact amounts, but the result is very

important for a social understanding of how strongly

respondents themselves value their own salaries. Fig. 5 shows

social results from the respondentsʼ standpoint in which 67%

feel their salaries are better and therefore value their salaries

highly. In another question, exact salaries were asked. In

order to examine the interaction of income and English more

strongly, we performed a correlation test （Table 11）. The test

correlated the respondentsʼ income with English level of the

five businesses. orrelation coefficients range between -1 and

+ 1 ; those closer to + 1 are significant, and those closer to -1 are not significant, particularly for our study. s suspected,

the test showed positive correlations in all businesses except

for travel agencies. This is due to the small sample size and

non-standardization of travel agency businesses which are still

in their infancy and do not share information readily. In social

research relating to income and English proficiency, strong

correlations are difficult to find. This study contains a strong

social aspect of business in Cambodia, a country of deep-

seated tradition. Therefore it is not enough to rely on

numerical values alone.

　　Fig. 6 shows the need for English is quite high, as the

service workers must use it regularly in day to day tourism

situations, as most tourists use EIL in communication. From

this data it can be seen that 66% use it regularly in their jobs;

Figure 4 . Source : Photo by author, Siem Reap, Cambodia, August 2007

Figure 6 . E nglish U sage

Source: Compiled from survey data by author, 2 0 1 0

Table 12 contains mean values of certain variables from the survey of the five businesses.

These variables were chosen as they display several different areas of English learning and usage.

As can be noted, average income levels ranged from US $68.15 to US $117. 05 per month.

Spoken English level, determined during face to face interviews using criteria designed by the

author on a scale of 0 to 5 , ranged from 2 ( high beginner) in souvenir shops to 3 ( low

intermediate) in travel agencies. This is probably due to the fact that travel agency employees

had to use English in communication with overseas travel companies often, and had to possess

higher levels to book flights and access information online. The highest paying jobs were in

hotels and travel agencies, with mean income at US $104 and US $117 respectively per month.

Income rises correspondingly with hours of English in school in all jobs. English levels are

higher with higher income jobs except for hotels. The author supposes this is due to the fact that

guest house front staff become quite close to guests, whereas hotel staff check in guests only.

Travel agencies have the highest salary, English level, most total years of schooling, and most

hours of English study per week in school. This indicates that travel agencies offer high incomes

but require more education and English study. Although we cannot prove causation, we can say

there is a positive relationship between English proficiency, employment, and income in the

Siem Reap tourist industry.

15

Figure 6. English Usage

Figure 6 . E nglish U sage

Source: Compiled from survey data by author, 2 0 1 0

Table 12 contains mean values of certain variables from the survey of the five businesses.

These variables were chosen as they display several different areas of English learning and usage.

As can be noted, average income levels ranged from US $68.15 to US $117. 05 per month.

Spoken English level, determined during face to face interviews using criteria designed by the

author on a scale of 0 to 5 , ranged from 2 ( high beginner) in souvenir shops to 3 ( low

intermediate) in travel agencies. This is probably due to the fact that travel agency employees

had to use English in communication with overseas travel companies often, and had to possess

higher levels to book flights and access information online. The highest paying jobs were in

hotels and travel agencies, with mean income at US $104 and US $117 respectively per month.

Income rises correspondingly with hours of English in school in all jobs. English levels are

higher with higher income jobs except for hotels. The author supposes this is due to the fact that

guest house front staff become quite close to guests, whereas hotel staff check in guests only.

Travel agencies have the highest salary, English level, most total years of schooling, and most

hours of English study per week in school. This indicates that travel agencies offer high incomes

but require more education and English study. Although we cannot prove causation, we can say

there is a positive relationship between English proficiency, employment, and income in the

Siem Reap tourist industry.

ompiled from survey data by author, 2 0 1 0ompiled from survey data by author, 2 0 1 0ompiled f

15

Figure 5 . Is your salary Better W ith E nglish Proficiency?

Source: Compiled from survey data, 2 0 1 0

Table 1 1 . Correlation Results of Income and E nglish Level Business Correlation Coefficient Souvenir 0 . 0 9 Restaurants 0 . 1 5 Guest Houses 0 . 5 2 Hotels 0 . 2 9 Travel Agencies -0 . 0 3

Source: Calculated using survey data, 2 0 1 0

Fig. 6 shows the need for English is quite high, as the service workers must use it

regularly in day to day tourism situations, as most tourists use EIL in communication. From this

data it can be seen that 6 6 % use it regularly in their jobs; 1 8 % have to use it to explain things in

detail, where 16 % use it to assist visitors only.

14

Figure 5. s your salary etter ith English Proficiency

Figure 5 . Is your salary Better W ith E nglish Proficiency?

Source: Compiled from survey data, 2 0 1 0

Table 1 1 . Correlation Results of Income and E nglish Level Business Correlation Coefficient Souvenir 0 . 0 9 Restaurants 0 . 1 5 Guest Houses 0 . 5 2 Hotels 0 . 2 9 Travel Agencies -0 . 0 3

Source: Calculated using survey data, 2 0 1 0

Fig. 6 shows the need for English is quite high, as the service workers must use it

regularly in day to day tourism situations, as most tourists use EIL in communication. From this

data it can be seen that 6 6 % use it regularly in their jobs; 1 8 % have to use it to explain things in

detail, where 16 % use it to assist visitors only.

14

Fig. 3 illustrates that English is indeed necessary due to the influx of English speaking

visitors; 85 % of the labor force stated that native English speaking tourists, EIL speakers, and

other Cambodians visit their establishments every day. The fact that both native English

speakers and EIL speakers visit daily shows that English is absolutely needed daily for work in

the tourism industry in Siem Reap.

Figure 3 . Freq uency of N ative Speaker V isits

Source: Compiled from survey data by author 2 0 1 0

The frequency of English speaking tourists and use of EIL has made English a job

requirement as seen in the photo in Fig. 4 ; the ability to communicate in English is essential in

most jobs, even entry level. Respondents reported that their salaries were higher than previously

and were elevated with English proficiency. In this survey, English proficiency and income was

analyzed both socially and numerically. The social survey question on salary was not based on

exact amounts, but the result is very important for a social understanding of how strongly

respondents themselves value their own salaries. Fig. 5 shows social results from the

respondents' standpoint in which 6 7 % feel their salaries are better and therefore value their

salaries highly. In another question, exact salaries were asked. In order to examine the

interaction of income and English more strongly, we performed a correlation test ( Table 1 1 ) .

The test correlated the respondents' income with English level of the five businesses. Correlation

coefficients range between -1 and + 1 ; those closer to + 1 are significant, and those closer to -1 are

not significant, particularly for our study. As suspected, the test showed positive correlations in

12

Figure 3. Frequency of Native Speaker V isits

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─ 27 ─


18% have to use it to explain things in detail, where 16% use

it to assist visitors only.

Table 12 contains mean values of certain variables from the

survey of the five businesses. These variables were chosen as

they display several different areas of English learning and

usage. As can be noted, average income levels ranged from

US $ 68 . 15 to US $ 117 . 05 per month. Spoken English level,

determined during face to face interviews using criteria

designed by the author on a scale of 0 to 5, ranged from 2 （high beginner） in souvenir shops to 3 （low intermediate） in

travel agencies. This is probably due to the fact that travel

agency employees had to use English in communication with

overseas travel companies often, and had to possess higher

levels to book flights and access information online. The

highest paying jobs were in hotels and travel agencies, with

mean income at US $ 104 and US $ 117 respectively per

month. Income rises correspondingly with hours of English in

school in all jobs. English levels are higher with higher

income jobs except for hotels. The author supposes this is due

to the fact that guest house front staff become quite close to

guests, whereas hotel staff check in guests only. Travel

agencies have the highest salary, English level, most total

years of schooling, and most hours of English study per week

in school. This indicates that travel agencies offer high

incomes but require more education and English study.

Although we cannot prove causation, we can say there is a

posi t ive relat ionship between English proficiency,

employment, and income in the Siem Reap tourist industry.

　　Table 13 contains standard deviations which show the

amount of dispersion or variation from average values. Low

standard deviation values show that data is clustered around

the central line of data; high standard deviations indicate data

spread over a large range of values. Standard deviation

analysis can be a way to verify data and to show confidence in

statistical outcomes. In a normal distribution, we would

expect to find values within 3 standard deviations from the

Table 12. Means, Tourism Labor Force, Siem Reap, 2010.

Type ofBusiness

Income Age EnglishLevel

Total Yearsof School

Money spentforEnglishPer month（US$）

Hours ofEnglish inSchool（hrs/wk）

Use ofEnglishPer month（days/mo）

SouvenirShops

68.15 25.04 2 10.2 10.34 4.04 26.38

Restaurants 69.70 22.91 2.3 10.97 8.35 4.85 29.47

Guest Houses 72.38 22.57 2.33 13.09 10.47 5.23 22.42

Hotels 104.47 24.92 2.28 12.60 14.52 7.06 26.28

TravelAgencies

117.05 26.05 3 14.47 12.58 8.17 27.88

Source: Calculated based on survey data, 2010

Table 13. Standard Deviations, Tourism Labor Force, 2010.

Type ofBusiness

Income Age EnglishLevel

TotalYearsofSchool

Money spentforEnglishPer month（US$）

Hoursof Englishin School（hrs/wk）

Use ofEnglishPer month（days/mo）

SouvenirShops

33.58 7.35 1.27 2.65 22.64 3.98 8.9

Restaurants 20.37 2.57 0.87 2.62 12.48 4.08 3.08

Guest Houses 37.23 3.18 1.27 2.71 11.08 1.89 11.43

Hotels 39.49 4.66 1.24 2.57 11.65 7.09 5.99

TravelAgencies

57.91 3.64 1.52 2.97 14.55 6.8 8.96

Source: Calculated based on survey data, 2010

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mean. The values in Table 13 show a large spread of values

for income, showing that subjects had incomes that in

actuality were quite spread out from the mean; some

respondents earned high incomes and some low. This is due

to outliers in the data which have skewed the results. The

highest standard deviation was in the variable income in travel

agencies. This is an indication that travel agencies are

comprised of many types, and many had different jobs and

payment situations within travel agencies and therefore

differing incomes. In addition, there is no standardization in

travel agencies, nor is there perfect competition. Wage

information is limited because travel agencies are still in their

infancy. The standard deviations reflect the real situation of

travel agencies even though the results are low. Standard

deviations in expenditure for learning English monthly was

also high. English ability and background are different in each

business because economic affordability is different. Even so,

Cambodians themselves know English is important for

employment so that is why they spend time and money to

learn English, especially those in their 20ʼs.

9 . 　Conclusion

　　Although time, financial ability, and manpower was

insufficient to examine other facets, it is obvious that English

proficiency, total years of school, hours of English study in

school, usage of English per month, and money spent on

learning English monthly may have all contributed to better

jobs. Of course, this fact is not disputed; everyone agrees that

English plays a role in employment in tourism. However, the

author wished to prove this point statistically. Although the

sample was small, and only took place in Siem Reap, it could

be determined that increase in income was positively related

to English ability. Many tourists are from inner circle

countries, who use EIL daily to engage in tourism activities.

Therefore, without proficiency in English, young ambodians

may have difficulty getting good jobs in tourism. Every

Cambodian knows that with English ability they can get a

better job. We can simply say that they need English because

they are using it. The data may be lacking, but it is worthy of

pioneer study. More research in English proficiency and

employment needs to be completed. The survey was basic

and although it was not rigorous, the author was able to obtain

important background data, much of which has not been

collected before. It would make sense to continue this type of

research in the future.

1 0 . 　Implications for Future Research

　　English is important in the tourist industry in Cambodia.

However, very little training in specific English s ills exists.

In addition, standardized testing and standardized English

proficiency measurement are virtually non-existent there, and

should be implemented further in the future. This would

enable employers to adequately determine English level and

provide training for their employees.

　　Business owners and managers should continue to

monitor the English needs of their employees and to train

them towards such requirements. This would enable the

employer to offer stable employment. The employee would

also benefit the tourism industry by creating an enriching,

interesting tourism experience for guests.

References

BBC News Asia-Pacific. （November 6, 2012）. Cambodia

ro le Chronology of Key vents.

Retrieved from http: / / www. bbc. co. uk/ news/ world-asia-

pacific-13006828 January 5, 2013.

Cambodia Ministry of Tourism. （2010）. Tourism Statistics

nnual eport . National Institute of Statistics, 2010.

Clayton, Thomas. （2006）. Language Choice in a ation

nder Transition nglish Language Spread in Cambodia.

Springer, Kentucky.

Cuyvers, Ludo; Soeng, Reth; V an del Bulcke, Daniel. （2006）.

Foreign Direct Investment of Least Developed Countries: The

Case of Cambodiaʼs Textile, Garment, Furniture, Transportation

and Tourism Industries. Center for S Studies C S

Discussion Paper No. 49.

Department of Tourism, Siem Reap, Cambodia. （2010）. Interview

Regarding Total Number of Establishments in Siem Reap.

Economic Institute of Cambodia. （2008）. Cambodia’ s Labor

arket and mployment.

Retrieved from http: / / siteresources. worldbank. org/

INTDEBTDEPT/ Resources/ 468980-1218567884549/

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5289593-1224797529767/ CambodiaDFSG02. pdf May 27, 2010.

Economy Watch. （2010）. Cambodia trade: Imports and

ports. Retrieved from http: / / www. economywatch. com/

world_ economy/ cambodia/ export-import. html January 6, 2013.

Ennew, C. （2003）. Understanding the Economic Impact of

Tourism. Som ath Chib emorial Lecture.

Kachru, B. B. （1985）. Standards, codification and sociolinguistic

realism: the English language in the outer circle. In R. Q uirk

and H. G. Widdowson （Eds）, nglish in the world Teaching

and learning the language and literatures （pp. 11‒30）. Cambridge: Cambridge University Press.

Photius. （1987）. Cambodia foreign trade and aid ecember

.

Retrieved from http: / / www. photius. com/ countries/ cambodia/

economy/ cambodia_ economy_ foreign_ trade_ and_ ai~ 19 . html

January 5, 2013.

V istawide World Languages and Cultures. （2012）. Top Thirty

Languages by umber of ative Speakers . Retrieved from

http: / / www. vistawide. com/ languages/ top_ 30 _ languages. htm

May 27, 2012.

World Travel and Tourism Council （WTTC）. （2010）.

Cambodia conomic mpact eport.

WTTC Retrieved from http: / / www. wttc. org/ bin/ pdf/ temp/

Cambodia March 2, 2011.World Travel and Tourism Council （WTTC）. （2010）.

orld conomic mpact eport.

Retrieved from http: / / www. wttc. org/ research/ economic-

impact-research/ May 15, 2011.

Yoneoka, J. （2009）. The Role of Linguistic Auditing and

English as an International Language in the East Asian Tourist

Industry. The Institute of Economics and Business,

Kumamoto Gakuen University. , Research Report, V olume 100

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Helping Pre-service Teachers Enter the Community of Practice of Professional Educators through Collaborative Lesson Study東海大農紀要　34：31－37（2015）

Motivations for this study

　　This research on collaborative lesson study, a special

subset of action research, stems from a series of oral

interviews conducted with co-workers in the English

department at a junior high school （JHS） attached to the local

public university. The goal was to locate areas where the

teachers might be having problems with which research on

collaborative lesson study might prove helpful in resolving.

An experienced in-service Japanese teacher of English （JTE） revealed that she was not satisfied with the quality of

pedagogical guidance for the teacher development necessary

for the pre-service teachers （PSTs） coming from the faculty

of education at the university.

　　Japanese teachers at junior high schools in Japan are

extremely busy with many duties outside of teaching, such as

attending a growing number of meetings, managing club

activities, preparing the students for high school entrance and

generally acting as surrogate parents, all of which makes

adding the pre-service teacher development duties a bit

overwhelming. In addition teachers are often left on their own

with little in the way of formal guidance from the university

or colleagues on how to actually go about teacher training.

The general pattern is that PSTs first observe the JTE for a

few lessons, then are assigned a week of teaching on their

own, which is observed by the JTE and other PSTs.

　　The process of how to conduct lesson planning is

generally left up to the PSTs themselves. After consulting with

a teacher development expert at the university, a series of

collaborative lesson study cycles were conducted in an effort

to investigate and improve the quality of PST training.

Background

Communities of Practice

　　The concept of “a community of practice” （CoP） first

appeared in Situated Learning （Lave & Wenger, 1991）, and

denotes a group of people who share a craft or a profession.

Lave and Wenger described how outsiders to the profession

could gradually move towards an inner core of experts or “old

timers” through the process of sharing information and

experiences, allowing members to learn from each other, and

have an opportunity to develop themselves personally and

professionally.

　　The term was new but the phenomenon goes back as far

as humans have been storytelling and sharing experiences.

Wenger （1998）, in Communities of Practice, further expanded

and modified the concept. He explains that this theory does

not replace other theories of learning, but rather focuses on a

different slice of the problem of learning, which has many

dimensions. He summarizes the important features of

knowledge and knowing as being premised on the fact that we 東海大学非常勤講師

Helping Pre-service Teachers Enter the Community of Practice of Professional Educators through Collaborative Lesson Study

Michael Rupp

要旨　この研究は中学校で英語教員と大学からの実習生 ( PST, pre-service teachers) が参加した共同授業研究 ( LS, lesson

study) の結果の１つを報告するものである．共同 LSは授業の計画段階から，模擬授業，実践，改善，再実践，最終反省会まで LSグループの全員が対等な参加形式の研究法である．LSは元来日本の研究法で，最近特に数学教育では海外でも注目されている．しかし，日本では中学校以降では共同 LSはあまり見られない．今回の LS研究のデータの分析によって PSTが LSの結果で短時間に実践共同体 ( CoP, community of practice) の一教員としてのアイデンティティーをもつようになることが分かった．

（Received 19 October 2014; Accepted 8 December 2014）

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Michael Rupp

are social beings who are trying to experience the world in a

meaningful way, wherein knowledge is a valued competence

and knowing is the pursuit of active engagement in the world.

　　Wenger adopts the perspective that learning is not

something that only takes place in classrooms, but rather is a

natural human activity that is a fundamentally social

phenomenon . He pos i t s tha t much o f the typ ica l

institutionalized type of learning and training is perceived of

as irrelevant, arduous and boring by learners precisely

because it is divorced from our normal lives, separated into

unnatural, distraction free （free of the distractions of the real

world） learning environments. He suggests that we might be

quite good at learning if we did it in the context of social

participation in the real world.

　　This social constructivist view of learning can be seen to

have commonalities with social learning theories （Bandura,

1977） and social constructivist theories of V ygotsky （1978）, though in actuality the focus of Wenger is quite different, as

Bandura is looking at the cognitive processes of observational

learning, and V ygotsky is concerned with the activity of

learners developing skil ls in the zone of proximal

development, the zone where someone can perform tasks with

the help of a more knowledgeable other, such as a parent or

teacher. The zone is an area where development occurs,

al lowing the learner to expand to further zones of

development. Wenger focuses on the function of the member

in the group through internalization of norms and construction

of identities in the group.

　　In explaining how sociocultural and social constructivist

theories have come to greater prominence in dealing with the

challenges of education in this rapidly changing world Wells

（1999） describes how Lave and Wengerʼs concept of situated

learning can help us to look at our situated activities, our

workplaces, our classrooms and learning activities in a new

way, as chances for change and growth. Learning is seen as

being an integrated part of life, rather than a separate activity.

This is similar to the idea of lifelong learning, a term known

as shōgai gakushū （生涯学習）, popularly used in Japan when

discussing education reform （MEX T, 2014）.　　The construction of knowledge through dialogue with

peers is required for lifelong learning in the workplace CoP.

Dialogic knowledge construction （Wells, 1999） is the basis

for the learning involved in the collaborative lesson study

framework, and it has the key features of: being intrinsic to

action; being created socially ; and occurring through

meaningful discourse.

　　Lesson study provides an example of the first feature, as

the goal or object of the activity is defined, in this case, by the

lesson. The lesson defines the situated nature where learning

can occur in a setting with common or overlapping goals. The

second feature is also implicit in lesson study, as it requires

people to work together on the lesson. This is the social aspect

of knowledge construction. The third feature is enacted

through lesson study as the members negotiate meaning

through discussion, reflection, observation and sharing of

knowledge and ideas. Franklin （1996） sums up this process

of the creation and recreation of knowledge as being “in the

discourse between people doing things together. ”Wells （1999, p. 59） summarizes the key features of a

postmethod classroom:

1. The Classroom is Seen as a Collaborative Community

2. Purposeful Activities Involve Whole Persons

3. Activities are Situated and Unique

4. Curriculum is a Means not an End

5. Outcomes are Both Aimed For and Emergent

6. Activities Must Allow Diversity and Originality

　　　　The idea of the curriculum being a means, not an end, is

similar to the idea in lesson study which is that the actual

benefits of lesson study are seen as coming from the process

of collaboration, resulting in teacher development, rather than

on narrowly focusing on trying to make a ʻperfect lessonʼ. 　　The benefits of collaboration in action research （Stringer,

2007 ; Burns, 2010 ; Izumi, 2009） are gained through

opportunities allowing the participants to speak extensively

about what they perceive and experience, challenging their

own ideas and findings in extended dialogues which open up

new ways of thinking and create new possibilities that would

not have been possible otherwise. Exploring and reflecting on

students' behaviors and performance in class becomes an

effective strategy for both the improvement of lessons and

professional teacher development.

　　Figure 1 （Wenger-Trayner, 2013） below, shows the

various levels of participation in the community, from

complete outsiders, to lurkers and beginners on the peripheral,

all the way to leaders at the core of the community.

　　In the levels of participation model, when conducting

lesson study with PSTs, the PSTs would belong to the

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beginners on the periphery trying to move through the

occasional group to become experts within the active and core

groups.

Lesson Study

　　Lesson study （LS） has its origins in a traditional

Japanese teacher training method dating back to more than

100 years ago. Recently it has become popular outside of

Japan, particularly in mathematics education （Fernandez,

2002; Fernandez & Yoshida, 2004）. The term itself is a direct

translation from Japanese, jugyō kenkyū （授業研究）, and is

occasionally called ʻlesson researchʼ . It typically involves a

team of teachers who collect data from live lesson

observations in order to collaboratively analyze teaching and

learning. Lesson study is a cyclical system of inquiry, similar

to action research （Lewis, 2008）, in which the collaborative

accumulat ion of knowledge is sought and wherein

practitioners can build theories, learning from each other as

they research, plan, teach, observe, revise and discuss a

classroom lesson.

　　Laskowski （2009; 2011） describes lesson study as a way

forward for teacher developers in the postmethod condition

（Kumaravadivelu, 1994 ; 2005）, where there is no single

model or approach that can be applied to the complex realities

of the classroom. Laskowski points out that lessons underpin

all that is vital in a teacher' s methodology, as all activities and

decisions stem from the method. This form of teacher

development is also less threatening to teachers, as the lesson

is the focus, and the group shares responsibility for the lesson.

　　Lesson study is truly teacher oriented by being both

teacher-directed and teacher-driven, unlike typical

professional development seminars where the participants sit

and passively listen, taking in words of wisdom from above

（Lewis & Hurd, 2011）. Participants in lesson study seek their

own information and do their own research.

Lesson Study with Pre-service Teachers

　　There is little available research on PSTs and lesson

study, however Burroughs and Lubeck （2010） note that

collaborative lesson study was found to be meaningful to

PSTs and allowed them to more quickly become ready for

leadership roles, becoming more invested in the process of

their teacher development, and giving them new ideas about

how to develop and enact lessons.

Figure ₁. Levels of participation (Wenger-Trayner, 2₀₁₃).

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Michael Rupp

　　They further mention how over time PSTs became more

invested in the process, an outcome that corresponds well

with the results of my own PST lesson study cycle. Finally

they warn that good lesson study requires effort and if

teachers do not put in the time and effort, it can end up being

ineffective. This aspect, especially the time factor, is one of

the largest limitations encountered in implementing

collaborative lesson study.

Methodology - A Qualitative Approach

　　The methodological approach of this study is based on

qualitative research traditions （Burns, 2003） and applies a

qualitative research approach that is exploratory, as it sets out

to understand the influences of having pre-service teachers go

through a collaborative lesson study process from a deeply

emic perspective. It is interpretive in the sense that the data is

collected and analyzed taking into account the first hand

perceptions of the pre-service teachers, the in-service teacher

and the experience based views of the researcher. The

outcomes arose naturalistically from the data and earned their

way into the study.

　　Participants

　　There were four participants, including: two 4th year

Japanese university students （PSTs: A-san and Y-san）; I-sensei an experienced junior high school Japanese teacher of

English （JTE）; and the author, as a participatory researcher

and the assistant language teacher （ALT） at the school.

Location

　　The lesson study cycle took place at a local Japanese

junior high school （JHS）. The classes taught were two

different third year （ninth grade） JHS classes, of 40 students

each.

Sources of data collection and analysis

　　Data was collected from each stage of the cycle based on

the principles of triangulation, utilizing a variety of sources.

All sessions were audio recorded, meetings were often video

recorded and all lessons were video recorded. Data was also

gathered from questionnaires, lesson observation logs,

reflection notes, teacher learning plans, lesson observations,

lesson plan revision notes, recorded interviews and interview

notes. Most of the interaction with the JTE and PSTs was

conducted in Japanese, and subsequently translated by the

author.

　　The six lesson study cycle stages （see Figure 2）

Stage 1　Defining Personal and Professional Development

Goals （PPDs） and Collaborating on Lesson Plan

Stage 2　Demonstration Lesson

Stage 3　Actual Lesson

Stage 4　Post Lesson Discussion

Stage 5　Revised Lesson

Stage 6　Final Reflections

　　This cycle can be repeated with different teachers and the

same lessons or the same teachers with different lessons in an

iterative process of knowledge construction. This six stage

model differs from that of Lewis （2008） in that it has an

added stage of the “demonstration” lesson, which is a dry run

of the lesson conducted in front of the LS group, in order to

work out any remaining issues before the actual lesson.

Analyzing the lesson study stages

　　The data was analyzed by a thorough cataloguing of the

sources of data at each lesson study stage. The outcomes,

which arose from these data sources, were then holistically

analyzed for emergent themes, one of which, the theme of

increased CoP investment by the PSTs, is discussed below. 　

Analysis and Discussion

　　In stage 1, a questionnaire was given to the two PSTs to

determine their personal and professional development goals

（PPDs）. These would serve as a guide during the lesson

planning, feedback and revision stages. Both PSTs showed a

preference for naturalistic and humanistic approaches in their

teaching, aiming for an enjoyable class in order to motivate

their students.

　　Both PSTs also indicated that they were concerned about

managing time and predicting how long activities would last

in a real classroom. They also showed some apprehension

about jumping into the middle of a class halfway through the

year, not knowing the true abilities and personalities of the

students. Y-san especially was concerned with developing her

ability to use classroom English （CRE）, which denotes the

incidental usage of English during class as opposed to the

target language of the lesson. It was clear that neither had

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heard much about collaborative lesson planning.

　　Disposition of the PSTs at beginning of the study

　　The PSTs appeared rather apprehensive at first about how

much of a burden the lesson study was going to be on them,

as they were already quite overwhelmed with tasks and

assignments. When the author first asked to meet with the

PSTs for the stage 1 meeting, the PSTs looked slightly

annoyed, perhaps indicating that they felt lesson study was

merely another burden, with wasteful meetings of little or no

benefit to them.

CoP Investment

　　CoP Investment emerged as a result of observing changes

in the PSTs, both Y-san and A-san over the course of the

study.

　　Lave （1991） describes the process of how the

“newcomer” becomes an “oldtimer”. 　　Newcomers become oldtimers through a social

process of increasingly centripetal participation, which

depends on legitimate access to ongoing community

practice. Newcomers develop a changing understanding

of practice over time from improvised opportunities to

participate peripherally in ongoing activities of the

community. Knowledgeable skill is encompassed in the

process of assuming an identity as a practitioner, of

becoming a full participant, an oldtimer.

（Lave, 1991, p. 68）　　This process was observed and emerged as a category in

the study, with the PSTs in the role of the newcomers. In stage

1, the attitude of the PSTs towards my involvement in their

teaching practicum, while not outright hostile, was certainly

one of hesitancy and non-engagement. This is evidenced

during the very first meeting we had, they were already

looking at their watches, and asking, “Could you make these

meetings shorter ? ” Later, this data was triangulated when I

reviewed the audio recordings, and found that when I had

stepped out of the room to retrieve a file, the girls had been

chatting with each other in Japanese, and I had inadvertently

recorded them saying things like, “This meeting seems like it

is really going to drag on . ” and “What time is it ? ”, confirming

the notion that they really just wanted the meeting to end

quickly. This meeting had been scheduled for 45 minutes, a

time limit which I kept. It was also a very important meeting

as it was our first meeting, wherein we had to confirm their

PPDs and the lesson plan. The PSTs could not seem to find

Figure 2. The six-stage lesson study cycle used in the study, adapted from Lewis(2₀₀₈).

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Michael Rupp

any value in collaborating with oldtimers, such as myself.

　　The first moves away from this newcomer attitude began

to appear in the first reflection session, stage 4, where it

appeared that the PSTs began to see the value in having a

team of experts assist them in the job, the realities of which

had begun to sink in. In stage 3 there had been unexpected

technical failures, unplanned for student reactions, and an

episode of unexpected failure to produce even simple CRE. It

was during these collaborative feedback and reflection

sessions where the PSTs began to join the JTE and the author

in a professional dialogue, debating teaching points, giving

and accepting professional advice and knowledge, and

thinking from the point of view of a teacher, rather than the

college students they actually were. The author noted in stage

4 that there was noticeable discomfort when the PSTs were

both giving and receiving feedback about the lesson. This

discomfort could be viewed as growing pains on the path

towards becoming a true member of the CoP of professional

teachers. The collaborative lesson study process, by its very

nature, forces the members to act as members of the CoP, and

thus take on such identities.

　　In s tage 4 , as the PSTs were expressing their

dissatisfaction in their CRE abilities, the JTE, an oldtimer,

commiserated with them that she too was still using mistake-

riddled CRE. This appeared to be a moment of bonding,

bridging a gap between the two, which created a sense of

camaraderie.

　　This sense of increased CoP involvement continued

through the LS, as both the PSTs were able to improve their

teaching performances based on the feedback they received

from the lesson study group. Before stage 5, Y-san spent

considerable time working with the author on her CRE, easily

going beyond an hour. There were no more requests to “keep

the meetings short”, in fact, it was more a case of the PSTs

asking for more time than was planned.

　　In stage 6, the author observed that the JTE and the PSTs

were now casually chatting, laughing and recounting teaching

stories with each other, before the meeting officially started.

This seemed to indicate an attitude that the professional

distance between the JTE and the PSTs had decreased

substantially. During the reflection session, this distance

decreased even further when Y-san was complimented by the

JTE on both her CRE and handling a difficult class of

students.

　　

Limitations

　　The problem of scheduling meetings is a repeated issue

throughout the lesson study cycles I have conducted, and it is

made more severe due to last minute schedule changes based

on needs of the junior high school. Fortunately, as the lesson

study progressed, the PSTs came to have a more favorable

attitude towards our collaboration, and even welcomed

spending extra time in discussion, perhaps as they were able

to see how it was becoming helpful to their teaching.

Conclusion

　　By the end of the study, the PSTs claimed that the

experience of going through a collaborative lesson study cycle

had allowed them to have much better lessons. Even members

who were not the subject of the lesson study but participating

only as observers claimed to have benefited in their own

teaching by observing and engaging in the feedback and

revision sessions. It is both encouraging and not terribly

surprising to hear that gains are to be had for all the members,

as we were all participating as equals in the CoP and taking

equal ownership of the lesson. The author was able to learn

new and fresh ideas with a different perspective from the

young and inexperienced PSTs, just as they learned things

from the highly experienced JTE and native speaker/ foreign

perspective insights of the author. This cross-pollination of

ideas and thinking is made only richer by the differences in

background, age, gender, experience and nationalities.

　　There is currently little evidence of collaborative lesson

study being conducted in the Japanese secondary school

system, which instead tends to have an emphasis on

demonstration teaching lessons, which are lacking the crucial

collaborative aspects during lesson planning, revision and

continued cycles of reflection and improvement. The author

believes that if the benefits of lesson study can be documented

through further research, there will be more support for

investing the time and effort necessary for this teacher

development model.

Summary

　　This paper examines one of the outcomes of the use of

collaborative lesson study （LS）, a cyclical teacher

development model, when applied to a junior high school

context involving training of pre-service teachers （PSTs）. The

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data collected during the study showed an emergent theme of

the pre-service teachers becoming invested in the community

of practice （CoP） of professional teachers. Most studies on

LS to date have focused on mathematics education, thus this

study can contribute evidence of LS benefits in English

education and also pre-service teacher training

References

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Burns, A. （2003）. Collaborative action research for English

language teachers. Ernst Klett Sprachen.

Burns, A. （2010）. Doing action research in English language

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Burroughs, E. A. , & Lubeck, J. （2010）. Pre-service teachers

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Enthusiast, 7, 391‒400.Fernandez, C. （2002）. Learning from Japanese approaches to

professional development the case of lesson study.

Journal of Teacher Education, 53（5）, 393‒405.Fernandez, C. , & Yoshida, M. （2004）. Lesson study: A

Japanese approach to improving mathematics teaching

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Franklin, U. （1996）. Introduction to the symposium, Towards

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Development: Jugyokenkyu （Lesson Study） from the

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Laskowski, T. （2011）. Jugyokenkyu （Lesson Study） in

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practice. Perspectives on socially shared cognition, 2, 63‒82.

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peripheral participation. Cambridge University Press.

Lee, C. D. , & Smagorinsky, P. （Eds.）. （1999）. Vygotskian

perspectives on literacy research: Constructing meaning

through collaborative inquiry. Cambridge University

Press.

Lewis, C. （2008）. Lesson Study: How Can It Build System-

Wide Improvement? In 2008 California Capital Lesson

Study Conference, May 16, 2008 at Sacramento State

http: / / www. csus. edu/ mase/ calessonstudy/ 2008 / docs/

proceedings/ Catherine_ Lewis. pdf

Lewis, C. C. , & Hurd, J. （2011）. Lesson study step by step:

How teacher learning communities improve instruction.

Heinemann.

Ministry of Education, Culture, Sports, Science and

Technology （MEX T）. （2014）. National Policies

Concerning Lifelong Learning.

　　Retrieved from < http : / / www. mext . go . jp / english /

lifelonglearning/ index. htm> .

Noffke, S. E. , & Somekh, B. （Eds.）.（2009）. The Sage handbook

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Limited.

Stringer, E. T. （2007）. Action research. Sage Publications,

Incorporated.

Wells, G. （1999）. Dialogic Inquiry in Education: Building on

the Legacy of Vygotsky. In C. D. Lee and P. Smagorinsky

（Eds.） Vygotskian perspectives on literacy research.

New York: Cambridge University Press, （pp. 51‒85）.Wenger, E. （1998）. Communities of practice: Learning,

meaning, and identity. Cambridge University Press.

Wenger-Trayner, E& B （2013）. Levels of Participation.

http: / / wenger-trayner. com/ resources/ slide-forms-of-

participation/ Accessed November 10, 2014.V ygotsky, L. S. , & Cole, M. （1978）. Mind in society: The

development of higher psychological processes. Harvard

University Press.

p31-37_Rupp.indd 37 2015/02/26 11:39:15

2015年３月15日発行

　　　発行所　　東海大学農学部　　　　　　　　　　〒869－1404　熊本県阿蘇郡南阿蘇村河陽　　　　　　　　　　電話　0967（67）－0611（代）

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EDITIONAL COMMITTEE OF PROCEEDINGS

Chairman Kiyotaka KabataMember Jun Abe Kazunari Yoneda Shinya Masuda

Published bySchool of Agriculture, Tokai University

Minamiaso-mura, Aso-gun, Kumamoto, ₈₆₉－₁₄₀₄Japan

東海大学紀要　農学部第34巻　　 2 0 1 5

hyousi.indd 2 2015/02/28 11:04:55

ISSN　1883－1516

東海大学紀要　農学部第　34　巻

2 0 1 5

バーク堆肥を用いたメロンの連作障害の抑制に関する研究　…………………………………………………………………森川充実・田中孝幸・吉田政博………１

チーズの70％エタノール可溶性画分を Sep-PakC18カートリッジにより分離した非吸着および吸着画分のペプチドと抗酸化活性　…………………………………………………………………近藤祐希・安田　伸・井越敬司………７

水生バイオマス「マコモ」の環境保全機能および生産性・機能性に関する研究　………………………仲川侑希・仁木博脩・長谷川大輔・橋本歩果・高橋智保・川合祐加　　　　　　　　　　　　　　　　　　　本田憲昭・岡本智伸・増岡智加子・安田　伸・椛田聖孝………13


Helping Pre-service Teachers Enter the Community of Practice of Professional Educators through Collaborative Lesson Study　 ………………………………………………………… Michael Rupp……31

PROCEEDINGSOF

SCHOOL OF AGRICULTURETOKAI UNIVERSITY

Vol. 34　　 2 0 1 5

Studies on the Control of the Injury by Continuous Cropping of Melon by Using Bark Compost　……………………………………… Atsumi Morikawa・Takayuki Tanaka and Masahiro Yoshida……１

Peptide and Antioxidative Activity of Non-adsorbed and Adsorbed Fractions Separated　by Sep-PakC18 Cartridge from 70 % Ethanol Soluble Fraction Extracted from Cheeses　………………………………………………………… Yuuki Kondo, Shin Yasuda and Keiji Igoshi……７

Studies on the Function of Environmental Preservation and the Productivity of Aquatic Biomass ʻʻWild Riceʼʼ　…………………………… Yuki Nakagawa, Hironobu Niki, Daisuke Hasegawa, Ayuka Hashimoto,　　　　　　　　　　　　　　　　　Chiho Takahashi, Yuka Kawai，Kensho Honda, Chinobu Okamoto,　　　　　　　　　　　　　　　　　　　　Chikako Masuoka, Shin Yasuda and Kiyotaka Kabata……₁₃


Helping Pre-service Teachers Enter the Community of Practice of Professional Educators through Collaborative Lesson Study　 ………………………………………………………… Michael Rupp……₃₁

東海大学紀要　農学部

第三四巻

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