International Rice Research Newsletter Vol12 No.6

8/4/2019 International Rice Research Newsletter Vol12 No.6

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IRRN growing and changing

TheInternational Rice Research

Newsletteris in its 12th year of

publication. In its first issue, October

1976, the IRRN objective was stated as:

To expedite communication among

scientists concerned with the

development of improved technology

for rice and for rice-based cropping

systems. This publication will reportwhat scientists are doing to increase

the production of rice, inasmuch as

this crop feeds the most densely

populated and land-scarce nations in

the world . . . IRRN is a mechanism

to help rice scientists keep each other

informed of current research

findings.

That remains our objective.

To meet that objective in the

expanding and increasing complexity of

the rice research world, we are initiating

some changes, effective with the 1988

publication year. The family of rice

researchers is growing exponentially. We

distributed 6,000 copies of IRRN Vol. I,

No. 1; we will distribute close to 13,000copies of Vol. 12, No. 4, to individual

scientists and to the libraries of research

institutions. The first issue totaled

24 pages; some issues this year totaled

54 pages. The number of research brief

reports being submitted has more than

doubled, and grows daily.

For IRRN to continue to meet its

objective efficiently and with increased

quality, the categories of research

reported are being expanded to include

new specializations and topics now

being researched. The Guidelines for

Contributors have been expanded and

specified more precisely. Criteria for

reviewers emphasize the global nature ofrice research work reports that will be

accepted.

The concise reports contained in

IRRN are meant to encourage rice

scientists and workers to communicate

with one another. In this way, readers

can obtain more detailed information onthe research reported.

Please examine the new categoriesand the new guidelines that follow.

If you have comments or suggestions,

please write the editor, IRRN. We look

forward to your continuing interest in

IRRN.

Guidelines for contributors to IRRN

TheInternational Rice Research

Newsletteris a compilation of research

briefs on topics of interest to rice

scientists all over the world.

Contributions to IRRN should be

reports of recent work and work-in-

progress that have broad interest andapplication. Please observe these

guidelines in preparing submissions: The report should not exceed two

pages of double-spaced typewritten

text. No more than two figures

(graphs, tables, or photos) may

accompany the text. Do not cite

references or include a

bibliography. Items that exceed the

specified length will be returned.

research objectives and project

design. The discussion should be

brief, and should relate the results

of the work to its objectives. Report appropriate statistical

analysis.

Provide genetic background for

new varieties or breeding lines.

Specify the environment (irrigated,rainfed lowland. upland, deep

water, tidal wetlands). If you must

use local terms to specify landforms

or cropping systems, explain or

define them in parentheses.

transplanted, wet seeded, dry

seeded).

Specify seasons by characteristicweather (wet, dry, monsoon) and

by months. Do not use national or

local terms for seasons or, if used,

define them.

When describing the rice plant andits cultivation, use standard,internationally recognized

designators for plant parts and

growth stages, environments,

management practices, etc. Do not

use local terms.

studies, be sure to include standard

soil profile description,classification, and relevant soil

properties.

diseases, insects, weeds, and crop

plants; do not use common names

or local names alone.

Survey data should be quantified(infection percentage, degree ofseverity, sampling base, etc.).

When evaluating susceptibility,resistance, tolerance, etc., report the

actual quantification of damage due

to stress used to assess level or

incidence. Specify the

measurements used. Use international measurements.

Do not use local units of measure.

Express yield data in metric tons

per hectare (t/ha) for field studies

and in grams per pot (g/pot) or perrow (g/row) for small-scale studies.

Express all economic data in termsof the US$. Do not use national

monetary units. Economic

information should be presented at

the exchange rate $:local currency

at the time data were collected.

Use generic names, not tradenames, for all chemicals.

When using acronyms orabbreviations, write the name in fullon first mention, following it with

the acronym or abbreviation in

parentheses. Thereafter, use the

abbreviation.

Define in a footnote or legend anynonstandard abbreviations or

symbols used in a table or figure.

Include a brief statement of

Specify the type of rice culture (e.g.,

When reporting soil nutrient

Provide scientific names for

IRRN: categories of research

reported

GERMPLASM IMPROVEMENT

genetic resources

genetics

breeding methods

yield potential

grain quality and nutritional value

disease resistanceinsect resistance

drought toleranceexcess water tolerance

adverse temperature tolerance

adverse soils tolerance

integrated germplasm improvement

research techniques

data management and computer

modeling

IRTP

seed technology

CROP AND RESOURCE

MANAGEMENT

soils and soil characterizationsoil microbiology and biological N

physiology and plant nutritioncrop management

soil fertility and fertilizer management

INSFFER

disease management

insect management

weed management

managing other pests

integrated pest management

water management

farm machinery

environmental analysis

postharvest technology

farming systemsARFSN

research methodology

data management and computer

fertilizer

modeling

SOCIOECONOMIC AND

ENVIRONMENTAL IMPACT

environment

production

livelihood

EDUCATION AND

COMMUNICATION

training and technology transfer

communication research

information storage and retrieval

research

Criteria for IRRN research reports

has international, or pan-national,

has rice environment relevance advances rice knowledge uses appropriate research design

and data collection methodology

reports appropriate, adequate, data applies appropriate analysis, using

appropriate statistical techniques

reaches supportable conclusions

relevance


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Contents

GENETIC EVALUATlON AND UTILIZATION

Overall progress

4TPS2: a new high

-

yielding rice variety4 Performance of IRAT varieties at Ibadan, Nigeria

5 Six upland rice varieties released in Nigeria

5 Performance of shortduration rice varieties

6 Elite lines for rainfed lowlands in North Bihar, India

6 ADT37 released for Tamil Nadu

7 Rice varieties for delayed planting

7 Agronomic and yield characteristics of three elite upland rices in Tamil

Nadu

Germplasm

8 Some panicle characteristics of rice germplasm from the Northern

Province of Sierra Leone

Agronomic characteristics

8 Possibility of a ratoon crop from photoperiod-insensitive summer rices in

9 Sequential tiller separation a method for rapid rice seed multiplication

10 Foliar application of polyamines, kinetin, and ascorbic acid and rice

10 Contribution of aquatic tillers to grain yield in deepwater rice

calcareous sodic soils of North Bihar, India

grain filling

Grain quality

11 Effect of simulated rain on head rice yields of varieties under delayed

harvest

Disease resistance

12 Evaluation of National Uniform Rice Yield 1985 against bacterial blight

12 Resistance of rice germplasm to bacterial blight (BB) at Ludhiana, India

(BB) in Pakistan

Insect resistance

13 Sources of resistance to rice thrips

13 Varietal resistance to rice hispa

Cold tolerance

14 Spikelet sterility in winter rice

Drought tolerance

14 Response of short-duration rice cultivars to drought stress

15 Response of rainfed upland rice to chlormequat chloride

Adverse soils tolerance

15 Screening for zinc deficiency tolerance in rice

Temperature tolerance

16 Cold tolerance in dry season rice for deepwater areas of north Bihar,

India

Deep water

16 Sudha, a new deepwater rice variety in Bihar, India

17 NC493. a promising variety for rainfed deepwater areas

Hybrid rice18 Retardation of heading in male sterile and restorer lines using

18 Evaluation and use of male sterile systems in Mekong Delta, Vietnam

19 Susceptibility of A lines and B lines to bacterial blight (BB)

20 Yield evaluation of F1 hybrids in the Mekong Delta, Vietnam

paclobutrazol

Tissue culture

20 Induction of productive semidwarf mutants of Basmati rice

PEST CONTROL AND MANAGEMENT

22 Chemical control of rice false smut

22 Silica reduces disease on upland rice in a high rainfall area

23 White leaf streak disease on rice in India

23Cellular inclusions in rice grassy stunt virus (GSV)

-

infected rice23 Effect of neem oil on tungro (RTV) infection in susceptible and resista

24 Some pathological and physiological diseases of rice in Punjab

varieties

Insects

24 Antifeedant effect of sublethal levels of carbofuran against whitebacke

25 Rodent damage in Punjab ricefields, Pakistan

26 Composition of the rice leaffolder complex in Coimbatore, Tamil Nadu

26 Abdominal lateral lobe variations in females of Nilaparvata luge

27 Nira variety a susceptible host for mass rearing rice thri

27 Effect of insecticide treatment at different rice crop stages on carry-ov

27 Effect of some insecticide formulations against newly emerged yellow

28 Preference, oviposition response, and population growth ofStenchaeto

28 Ovicidal activity of insecticides against yellow stem borer (YSB)

29 Species composition ofNephotettix in Tamil Nadu

29 New genetic makeup of brown planthopper (BPH) populations

30 Artificial diet for rearing rice leaffolder (LF)

31 Effect of insecticides on rice gall midge (GM) and its parasit

31 Toxicity of five insecticides to the cricket Metioche vittaticoIlis (St

planthopper (WBPH)

India

biotypes from Korea

Stenchaetothrips biformis (Bagnall)

of yellow stem borer (YSB)

stem borer (YSB) larvae

thrips biformis (Bagnall) on selected rice varieties

Central Java, Indonesia

Platygastersp.

(Orthoptera: Gryllidae), a predator of some insect pests of rice

Weeds

32 Ludwigia species most prevalent broad-

leafed weeds in wet zon

ricefields of Sri Lanka

Other pests

32 Striga densiflora Benth., an angiospermic root parasite of rice i

Bangladesh

SOIL AND CROP MANAGEMENT

33 Efficiency of urea supergranule (USG) under water stress at differen

34 Effect ofAzospirillum inoculation on upland rice

34 Effect of leaf leachates of neem and sirish on the biomass production an

34 Efficiency of azolla as an organic source for rice

35 Effect of gypsum and pyrite with different moisture regimes on sodic so

35 Availability to wetland rice of nitrogen from cattle manure36 Effect of soil bulk density and soil texture on root growth

37 Poultry manure as a N source for wetland rice

38 Nitrogen-fixing potential of blue-green algae (BGA) from Keral

growth stages

pests ofAzolla pinnata

improvement and rice yield

ricefields

RICE-BASED CROPPING SYSTEMS

38 Effect of an interim summer crop in a rice - wheat rotation

39 Intercropping rice and pigeonpea

39 Response of rice to NPK in long-term jute - rice - wheat sequence

Diseases ANNOUNCEMENT21 Effect of sclerotia size ofRhizoctonia solani on infectivity on rice plants 40 New IRRI publications21 Time of spraying to control sheath rot (ShR)


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Genetic Evaluation and UtilizationOVERALL PROGRESS

TPS2: a new high-yielding rice Table 2. Reaction of TP1974 and IR20 to insects and diseases. Tamil Nadu, India.

variety

Score

a

O. Ramanathapillai, S. Kalaimani, G. Entry Disease Insect

Radhakumar, A. Idhayarajan, M.

Subramanian, and A. Sindhamathar, Blast Bacterial Brown Brown Leaffolder Gall White tip

Agricultural Research Station, bight spot planthopper midgenematode

Thirupathisaram, Kanyakumari District, TP1974 3 3 5 3 3 3 3Tamil Nadu, India IR20 3 5 7 9 77

In Kanyakumari District, Tamil Nadu,

farmers traditionally cultivate tall local

rice varieties that mature in 160-180 d

during the kumbaboo season (Sep-Oct

to Jan-Feb). The straw is used to feed

cattle. The local market preference alsois for coarse rice. However, with a

gradual reduction in seasonal rainfall,

farmers are slowly switching to medium-

duration varieties.

TP1974 is a semidwarf (90-95 cm tall)

derivative of the cross IR26/CO 40. It is

nonlodging and matures in 125-130 d.

In overall performance, TP1974 had a

mean grain yield of 4.3 t/ha, 22.5%

higher than IR20, and a straw yield of

8.2 t/ha, 34.4% higher than that of IR20

(Table 1). Yield potential is 6.1 t/ha.

The culture is resistant to seed

shedding, and is moderately resistant to

four pests and two diseases (Table 2).

Grain is short, bold, and white.

Cooking quality is good in both raw and

parboiled rice, with good consumer

preference. Culture TP1974 has been

released as TPS2 variety for

Kanyakumari District.

a1 = resistant, 3 = moderately resistant, 5 = moderately susceptible, 7 = susceptible, 9 = highly

susceptible.

Performance of IRAT varieties at

Ibadan, Nigeria

P. G. Pillai and J. K. Kehinde, National

Cereals Research Institute, Badeggi, Ibadan,

Nigeria

We evaluated a number of breeding

lines and varieties in the upland

environment of Ibadan, Nigeria. IRAT

varieties introduced from Ivory Coast

exhibit high yield potential in the

Advanced Variety Trials (AVT)

conducted under the Coordinated Rice

Evaluation Trial (CRET) and the

African Upland Rice Advanced Trials(AURAT). IRAT104, IRAT156, and

IRAT161 were tested in AURAT; the

others in CRET. Both nurseries were

laid out in the same location using the

same cultural practices.

and 8 entries each in 1985 and 1986CRET, IRAT133, IRATll2, and

IRAT144 were the 3 highest yielders. O

the average, all IRAT materials

outyielded check variety ITA257.

Of 15 medium-duration entries in

1984 and 1985 CRET, IRAT170 was th

second highest yielder. In 1985, Sel-

IRAT194 was the third highest yielder.

On the average, IRAT170 and Sel-

IRAT194 outyielded check variety

FARO 11 (see table). In 1986, the trials

suffered severe drought for several days

during vegetative stage. All IRATvarieties outyielded the check. In

addition to high yield and drought

tolerance, they possess resistance to

lodging and clean grains.

Of 12 short-duration entries in 1984

Performance of IRAT varieties in the upland environment at Ibadan, Nigeria, 1984-86.

Ht Days to Panicles

(cm) flowering (no./m2)

Grain yield (t/ha)

1984 1985 1986 AveragVariety

Table 1. Performance of TP1974 in research

station and adaptive research trials. Tamil

Nadu, India, 1979-84.

Grain yield Straw yield

Trial Trials (t/ha) (t/ha)date (no.)

TP1974 IR20 TP1974 IR20

1979-85 8 4.6 3.6 6.4 4.3

1982-83 11 4.1 3.4 10.8 8.2

1983-84 10 4.2 3.6 7.4 5.8

Mean 4.3 3.5 8.2 6.1

Short-durationIRAT133 97 75 216 4.9 4.0 3.7 4.2IRAT112 100 78 188 4.3 4.0 2.7 3.6IRAT144 105 84 267 3.2 3.8 2.7 3.2IRAT110 a 96 78 319 2.7 3.6 3.1IRAT146 102 86 198 2.9 2.5 2.5 2.6

ITA257 (check) 87 73 240 2.7 2.9 1.4 2.3

Medium-durationIRAT170 113 97 215 3.6 5.6 2.9 4.0Sel-IRAT194 103 93 218 3.0 5.4 1.5 3.3IRAT104 105 95 189 2.2 2.5 2.6 2.4IRAT156 b 100 98 203 2.0 2.6 2.3IRAT161 b 110 100 197 2.0 2.2 2.1FARO 11 (check) 131 96 184 3.4 3.7 1.4 2.8

a Not included in 1986 AVT. b Not included in 1984 AVT.

4 IRRN 12:6 (December 1987)


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Six upland rice varieties released in

Nigeria

S. O. Fagade, P. G. Pillai, and J. K. Kehinde,

National Cereals Research Institute (NCKI),

Badeggi, Ibadan, Nigeria

Six upland rice varieties, FARO 38 to

FARO 43, have been released forcultivation in Nigeria. They were best in

the 1984-86 multilocational Coordinated

Rice Evaluation Trials (see table).

Short-duration FARO 38 and 39 have

been recommended for dry upland

environments. They are high yielding

and resistant to diseases and drought.

Their grains are clean and short bold.

FARO 39 combines medium height and

better plant type. Its cooking quality is

also good. Both these varieties

outyielded short-duration check ITA257by 28%.

FARO 40, 41 ,42, and 43 are

medium-duration varieties

recommended for moist environments.

FARO 40, a composite developed at

NCRI, is resistant to lodging and

diseases. It possesses better cooking

quality than the commonly cultivated

variety FARO 11. FARO 41 was the

highest yielder (32% over check) among

the medium-duration entries. It

possesses better plant type and goodcooking quality. FARO 42 and 43 are

shorter than FARO 11 and are resistan

to lodging.

Performance of 6 newly released upland varieties in multilocation trials. Nigeria, 1984-86.

Ht Days to 50% PaniclesAv grain yield Amylose Reaction

b toGrain contentVariety Former name

(cm) flowering (no./m2) t/ha % over check typea (%) Blast Rice yellowmottle viru

Short-durationFARO 38 IRAT133

FARO 39 IRATl44ITA257 (check)

Medium-durationFARO 40 FAROX299FARO 41 IRAT170FARO 42 ART12FARO 43 ITA128FARO 11 (check)

aSB = short bold, MB = medium bold.

87 72 206 3.2 28

103 76 198 3.2 28

88 68 185 2.5

118 96 167 2.2 0100 97 177 2.9 32

105 96 172 2.8 27108 97 178 2.3 4123 97 179 2.2

bR = resistant, MR = moderately resistant.

SB

SBMB

MBMBMBMBMB

15.0 R

24.0 R14.0 R

22.0 R22.5 MR16.8 MR20.8 MR19.2 MR

MR

RR

RR

MRRR

Performance of short-duration rice

varieties

H.S. Bedekar and S. B. Murkute,

Agricultural Research Division, SciTechCentre, Village Aswe, Dahanu 401602,

Maharashtra, India

Short-duration, high-yielding rice

varieties were compared with Dangi

variety in three farmers' fields and at the

SciTech Centre farm during the 1985

and 1986 main crop seasons. Test plots

were in a completely randomized block

design replicated four times.

Seeds were sown on a raised bed in

Jun and transplanted at 21 d, at 20-

15-cm spacing in 32.4-m2 plots.

Fertilizer (100-50 kg NPK/ ha) was

applied to all plots and normal

management practices were followed.

Yields of K184, K23, Ratna, and

IR36 were similarly and significantly

higher than those of Dangi and K35-3

(see table). Ratna and R24 produced

significantly longer panicles, suggesting

high yield potential.

Ratna, R24, and K184 are normally

preferred by local farmers because of

their resistance to lodging and

substantially higher grain and straw

yields compared to Dangi. IR36 has

higher yields, but its straw yield is

lower.

Comparison of 6 short-duration varieties with Dangi (local) variety. Dahanu, Maharashtra, India, 1985-86.

Grain yield Straw yield Tillers

Variety Duration (t/ha)(d)

Origin (t/ha) (no./hill)

1985 1986 1985 1986 1985 1986

K184K23

100-110 Karjat (India) 4.1 4.3 1.9120-130 Karjat (India)

3.2 12.2 13.84.4 3.8 3.8

Ratna 110-120 KKV Dapoli (India)5.2

4.38.6 11.4

IR36 100-110 IRRI3.8 2.5 5.0 10.1 12.8

R244.1 3.9 2.4

120-130 Ratnagiri (India)4.4 10.7 13.6

4.5 2.8 2.1Dangi 110-120 Thane (India)

4.5 9.4 12.23.6 3.2 3.0 6.1 10.0

80-90 Karjat (India) 2.7 3.9 1.7 5.5 10.8 12.49.8

K35-3

Panicles Average pan

(no./hill) cle length (cm

1985 1986 1985 19

11.7 12.0 19.1 178.1 9.9 18.0 199.6 11.4 21.6 20

10.2 11.4 20.2 178.8 10.9 21.8 198.7 8.4 19.3 18

10.2 11.3 18.9 18

Mean

CD (0.05)

(0.01)

4.0 3.6 2.5

0.4

4.8 10.2 12.3

0.8

9.6 10.8 19.8 18

1.2 1.2

0.5 1.2 2.0 1.9ns ns 1.7 ns 1.3ns ns 2.6 ns 2.0 n

n

IRRN 12:6 (December 1987)


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Elite lines for rainfed lowlands in

North Bihar, India

B.N. Singh and S.P. Sahu, Plant Breeding

Department, Rajendra Agricultural

University, Pusa (Samastipur), Bihar 848125,

India

North Bihar, a medium-deep

waterlogged area, is planted primarily to

rainfed lowland rice. But in years with

poor rainfall, drought occurs at

vegetative or reproductive stages. Rice

tungro virus also causes major yield

losses in some years, bacterial leaf blight

occurs sporadically, and brown spot and

narrow brown leaf spot are severe in

years of poor rainfall.

Farmers usually grow traditional tall,

lodging-susceptible, and photoperiod-

sensitive varieties that can yield at least

1.5 t/ha under stress. Seedlings are

planted after the onset of rains in mid-

Jun, and transplanted 15-60 d after

seeding, after water accumulates in the

field. One or two applications of urea is

topdressed when water level lessens in

the field before flowering. Plant

protection is minimal.

Efforts are underway to select animproved nonlodging plant type, 150-

160 d duration, photoperiod-insensitive,

limited elongation, early seedling vigor,

and intermediate height (120-130 cm).

Evaluation of lines and segregating

generations from national and

international sources is in progress. Both

pedigree and bulk breeding methods are

being used. The segregating generations

are grown under shallow and

waterlogged rainfed lowland conditions

in alternate years to select desirable

types.

The major problem in improved

photoperiod-insensitive varieties is

sheath rot disease, maybe due to

variation in seedling age, seeding time,

or cooler temperature at flowering. Zn

deficiency in the seedling stage as well a

after transplanting have also becomemajor constraints in recombinant lines.

During 1985 wet season, when the

water level reached 80 cm, 154 entries in

6 replicated yield trials and 305 lines in

2 observational nurseries were evaluated

(see table). Yield varied; it was a

maximum 2 t/ha in both insensitive and

sensitive groups. The high-yielding

entries will be further evaluated in yield

trials, for use in hybridization

programs.

Elite lines that performed well in replicatedtrials and observational nurseries. Bihar, India,

1985 wet season.

Entries

tested Designation

(no.)

TrialIRRSWYN (M)

UVT-4 (DRR)

UVT-3 (DRR)

UVT-5 (State)

PVT-5 (State)

UVT-4 (State)

NurseriesIRRSWON

LLSN

28

31

20

26

25

24

203

102

BRB8-2B-74, BR 222-B-358, Matcandu

IET8005 (RP1486-834-l), IET7598

(RP1486-833-1)IET7520 (RP1854-

566-1-1-l), IET8033(RAU49-54-1-2),IET8611 (MTU 6861)TCA808, TCA48,

IET7970 (TCA80-4),

TCA148-3

SBIR38-140-2,

SBIR38-148-3IET6696 (IR42),

BIET1165 (RAU77-

l), IR3646-9-3-1

B4259-48-1-3-1-3,CN505-5-3-1, DudKalash, IR20880-25-

P1, Leuang Yai 148,

Matcandu

P3, IR21064-48-2-1E-

CN571-236-15-1,

CN570-661-48-3,OR611-8,OR620-17,OR620-52,OR621-6,CN706-2-26, CN569-705-8-1, CN566-915-63, CN363-3, CN578-190-7-1, CN567-682-25-3, CN580-869-42-3

ADT37 released for Tamil Nadu

A. P. M. K. Soundararaj, V.

Sivasubramanian, and S. Chelliah, Tamil

Nadu Rice Research Institute (TRRI),

Aduthurai 612101, India

BG367-4, an International Rice Testing

Program introduction evaluated in

Tamil Nadu since 1980, was released in

May 1987 as ADT37 for general

cultivation in the first crop season (Apr-

Jul sowing).

Mean grain yield was 6.3 t/ha, more

than that of IR50, ADT36, and TKM9

(Table 1). ADT37 yielded 4.9 t/ha in

multilocation trials, and 6.2 t/ha in

adaptive research trials (Table 2).

ADT37 is moderately tillering. Its

high yield potential is mainly due to

high panicle weight, in turn due to high

number of grains per panicle. Grains are

short and bold with white rice; milling

recovery is 71%. Cooking quality is

highly preferred.

ADT37 is resistant to leaf yellowing

disease, blast, brown spot, brown

planthopper, and green leafhopper; andmoderately resistant to bacterial leaf

blight, rice tungro virus, gall midge, and

leaffolder. It is highly suitable for direct

seeding.

Table 1. Performance of ADT37 at TRRI, Aduthurai, India, 1983-86.

GrainVariety yield

(t/ha)

Duration Panicles Panicle Grains

(d) (no./m2) wt (g) (no./panicle

ADT37 6.3 106 436 1.62 82IR50 5.3 103 542 1.21 68ADT36 5.7 108 510 1.35 73

TKM9 6.1 110 496 1.40 68

Table 2. Performance of ADT37 in trials in Tamil Nadu, India, 1985-86.

Mean grain yield (t/ha)

ADT37 IR50 TKM

TrialLocations

(no.)

Multilocation 6 4.9 4.2 4.7Adaptive research 57 6.2 5.9 5.7



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Rice varieties for delayed planting

S. K. Sharma, S. V. Subbaiah, and K. K.

Murthy, Directorate of Rice Research,

Rajendranagar, Hyderabad 500030, Andhra

Pradesh, India

Late onset of the monsoon, late receipt

of water by tail end canal farmers,

scarcity of labor during transplanting in

areas where the rice crop is in succession

with other crops, and other

socioeconomic problems can lead to

delayed transplanting, resulting in yield

reduction.

To identify rice varieties suitable for

different agroclimatic regions of India

and with mechanisms for adaptability to

late planting, we conducted trials with

promising cultures, standard checks, and

local checks during 1984, 1985, and

1986. N as urea was applied at 60 kg/ ha in

2 split doses 75% incorporated at the

last puddling, 25% 15-20 d later. P,

potash, and Zn were applied as

recommended. Seedlings were

Varieties evaluated for delayed planting at different locations. India, 1984 -86.

Standard check Local check Test variety

Name Yield Name Yield Name

(t/ha) (t/ha) (t/ha)

Location Planting date

Maruteru, 20 Aug 1984 IET7192 2.2 MTU7633 3.8 CR1018 4.1Andhra Pradesh

Mandya, 8 Sep 1986 IET7251 3.9 CTMl 3.7 Mandya Vijaya 5.4Karnataka

Pattambi, 20 Jul 1985 IET7251 1.6 H4 2.7 CNM539 2.6Kerala

Titabar, 10 Sep 1985 IET7251 3.1 Manoharsali 4.4 CNM539 4.2Assam

Chinsurah, 3 Sep 1985 IET7251 3.2 CNM539 3.5 NC492 4.0

West Bengal

Malda, 30 Aug 1985 IET7251 1.6 CNM539 3.3 NC492 4.3West Bengal

Mohanpur, 30 Aug 1986 IET7251 3.7 CNM539 2.6 IR42 4.4West Bengal

Kharagpur, 2 Sep 1986 IET7251 4.8 CNM539 2.7 CR1016 5.5West Bengal

Patna,Biha 15 Aug 1985 IET7251 4.3 Pankaj 2.5 CNM539 4.4

transplanted at 60 d, 20- 15-cm Pattambi could be planted late without

spacing, from late Jul to early Sep. any significant reduction in yield (see

All test varieties except CNM539 at table).

Agronomic and yield characteristicsat ARS from 1984 to 1987. Major

of three elite upland rices in Tamilentries were derived from hybrid

Naducombinations of two genotypes from

P. G. Nayagam and S. Natarajan,Agricultural Research Station (ARS),

Paramakudi; and G. S. Pandian, Agricultural

College and Research Institute, Madurai.

Tamil Nadu, India

We evaluated 186 upland rice entries

comprising local, indigenous, and exotic

collections in upland experimental fields

different ecogeographic zones. They

were compared with the local check

Nootripathu and the improved check

PMK 1. Three superior varieties

PM1390, AD35850, and IET7564

performed better than the improved

check PMKl (see table).

The varieties are short statured (55 to

73 cm) and have medium, dense panicles

Characteristics of elitee upland rice hybrid derivatives and local checks. Tamil Nadu, India, 1984-87.

Plant Panicle Spikelets Productive Duration Av

(cm) (cm) panicle) (no.) (d) (t/ha)Variety Parentage height length (no./ tillers

PM1390 IR13564/ASD4 73 19.5 75 8 110 3.1AD35850 ADT36/ADT29 59 18.6 69 8 108 3.0

IET7564 IRAT8/N22 55 16.4 59 7 90 2.6PMKl Co 25/ADT31 90 19.0 66 8 115 2.6(improved

check) Nootripathu Local land race 74 18.2 64 5 110 2.0(local check)

(16.4 to 19.5 cm) and 7 to 8 productive

tillers. They mature in 90 to 110 d.

Average maximum yields range from 2

to 3.1 t/ha.

resistant to drought as well as to lodgin

and are suitable for the eastern arid zon

of Tamil Nadu.

The screened cultures are highly

Complete slide sets of photos printed

in Field problems of tropical rice, revise

1983, are available for purchase at $50

(less developed country price) or $60

(developed country price), including

airmail postage and handling, from the

Communication and Publications

Department, Division R, IRRI,

P. O. Box 933; Manila, Philippines.

No orders for surface mail handling

will be accepted.


yield


8/40

Genetic Evaluation and UtilizationGERMPLASM

Some panicle characteristics of rice few nonshattering types were identified. Sierra Leone thus display wide

germplasm from the Northern The 1,000-grain weight varied widely variability in agronomic traits. After

Province of Sierra Leone (Table 2). That of most cultivars further evaluation, some of these

A. H. Hilton- Lahai, Rokupr Rice Research grains, and 6 had very large grains. programs for specific traits to suit the

Station (RRRS), PMB 736, Freetown, Indigenous rice cultivars in Northern needs of local farmers.

Sierra Leone

averaged 25-29 g; 5 had very small cultivars could be used in breeding

Characterization of important

agronomic traits of locally grown rice

germplasm in widely variable ecologies

is useful to programs breeding rice for

adaptability to diverse environments.

The agronomic traits of 150 indigenous

lowland rice cultivars collected in the

Northern Province of Sierra Leone wereevaluated at RRRS.

exsertion among the cultivars were low

(Table 1). Most cultivars displayed good

exsertion and low spikelet sterility, and a

Variations in panicle length and

Table 1. Variation in panicle length, spikeletsterility, and panicle threshability of indigenousrice cultivars from the Northern Province ofSierra Leone, 1987.

Varietal frequency

(no.) on the SES

a

scale of 1-9

13579

Panicle length 110 32 8Panicle threshability 9 12 47 92 Panicle exsertion 115 29 6Spikelet sterility 87 61 2

aStandard evaluation system for rice.

Character

Table 2. Variability in 1,000-grain weight of

some indigenous rice cultivars from the North-

ern Province of Sierra Leone, 1987.

1,000-grain

(g)weight range Cultivars (no,)

17.6-19.5 519.6-21.6 1021.7-23.0 1923.1-25.0 2725.1-27.0 1727.1-29.0 3629.1-31.0 3031.1-33.0 033.1-37.0 6


Genetic Evaluation and UtilizationAGRONOMIC CHARACTERISTICS

Possibility of a ratoon crop from

photoperiod-insensitive summerrices in calcareous sodic soils of

North Bihar, India

costs and free farmers for other fieldoperations.

advanced breeding lines Mar-Oct 1984

We studied the ratooning ability of 2

B.N. Singh, S.P. Sahu, S.S. Pandey, Plant

Breeding Department, Rajendra Agricultural

University, Pusa 848125, Samastipur, Bihar;

and J.S. Chauhan, Central Rainfed Upland

Rice Research Station, Post Box 48,

Hazaribag 825301, Bihar, India

Of the 5.6 million ha under rice

cultivation in Bihar, about 1 million ha

are under irrigated summer ricecultivation (Mar-Apr to Jun-Jul). Crop

harvest in Jul-Aug normally coincides

with the monsoon rains, thus leaving

little time for land preparation for the

main wet season (WS) rice planting. A

ratoon crop in WS would reduce labor

in an experiment in a randomized

complete block design with 3

replications. Forty-five-day-old seedling

were transplanted in 12-m2 plots at 2-

3 seedlings/ hill, with plants spaced 20

cm between rows and 15 cm within a

row. Fertilizer was 80-18-17 kg

NPK/ha. N was in 3 splits: 25% basal,

50% at tillering, and 25% at panicle

initiation. The soil was calcareous sandloam with pH 8.4 and EC 0.495 m.

At maturity the main crop was

ratooned by cutting the stalks 15 cm

above ground. Immediately after

harvest, 40 kg N/ha was applied.

Ratooning ability [(number of

Performance of ratoon selections. Pusa, North Bihar, India, 1984 DS and WS.

Growth duration Grain yield

RatooningVariety or line ability Main Ratoon % of Main Ratoon % o

(%) crop

(d)

crop main crop crop ma

(d) crop (t/ha) (t/ha) cro

CR222 MW 10 85.8 132 57 43 2.7 1.6 59IET7617 88.8 129 57 44 2.5 1.1 44

Rasi 87.8 128 57 45 2.4 1.4 58RP1664-4461-693-1333 94.9 142 59 42 2.4 1.7 71IR19743-25-2-2-3-1 59.4 129 49 38 2.3 1.1 48RP1158-172-1 94.0 129 59 46 2.3 1.3 57

94.5 133 59 45 2.2 0.8 36CR215-55-44-1 68.8 128 49 38 2.2 1.3 59

91.8 130 61 47 2.1 1.4 6774.3 133 57 43 2.1 1.1 52

IET7613

IET3279IR5B-36-70-1


9/40

regenerated hills in the ratoon crop/total

hills in the main crop) 100] was

evaluated 4 wk after main crop cutting.

Only 10 of 24 breeding lines showed

regeneration. Ratooning ability varied

from 59.4% to 94.9%, and ratoon

growth duration from 49 to 61 d (see

table). Thus, ratoon crop duration was

38-47% of that of the main crop.Ratoon height was slightly reduced but

Sequential tiller separation - a

method for rapid rice seed

multiplication

H.L. Sharma, H. Singh, H.S. Randhawa,

D. P. Joshi, and M.R. Gagneja, Seed

Research and Production Unit, Punjab

Agricultural University, Ludhiana, India

To increase seed production of elite rice

cultivars in a single season, we tried

transplanting single tillers after

repeatedly separating tillers. Five-day-

old seedlings of 4 rice cultivars

PR103, PR106, PR109, and Basmati

370 were transplanted 30 May 1986 at

40 seedlings each with 15- 30-cm

spacing. Each seedling developed 3-6

tillers within 18 d.

Effect of sequential tiller separation and trans-

planting on number of plants, yield, and seedmultiplication ratio. Ludhiana, India, 1986summer.

Split Plantsno. (no.)

Seed Seedyield multiplication

(kg/ha) ratio

0 101 402 1163 416

0 101 522 179

3 659

0 101 62

2 2253 953

0 101 382 97

3 390

PR 1031

51020

PR 1061

612

42

PR 10918

20

55

Basmati 37015

919

200

78115693302

25012352598

9332

2501468

34189705

125481

9311985

ratoon grain yield did not significantly

differ. RP1664-4461-693-1333 had the

highest ratoon yield (1.7 t/ha), and

IET7613 the lowest (0.8 t/ha) (see table).

The reduction in ratoon grain yield was

due primarily to smaller and fewer

panicles.

The ratoon crop harvest first week

Oct left ample time for the farmers to

Thirty seedlings of each cultivar were

uprooted and their tillers separated with

a sharp razor (split 1). The separated

tillers were retransplanted at 15- 30-

cm spacing in such a way that all tillers

of every 10 uprooted seedlings formed

one strip, for 3 strips/variety. The

schematic propagation of PR109 is

illustrated in the figure.

Ten days after the second trans-

planting, two strips of each variety were

uprooted and the tillers separated (split

2). Those tillers were retransplanted

3 Jul. On 18 Jul, seedlings from one

strip/cultivar were uprooted, tillers

separated, and transplanted (split 3).

Purple colored cultivar R575 was

transplanted around all strips of all

cultivars to control border effect.

The effect of sequential tiller splitting

and transplanting on number of plants,

seed yield, and seed multiplication ratiois given in the table. Maximum number

of plants was from the original 10

seedlings of PR109, the minimum was

with Basmati 370. Average increase in

number of plants, irrespective of

cultivar, was 62.

Seed yield did not increase in

proportion to plant numbers. This may

be due to reduced size and length of

panicles, higher floret sterility, and

reduced number of effective tillers.

Increase in seed yield ranged from 16

times in Basmati 370 to 39 times inPR109, with an average of 27 times that

of control.

Highest seed yield after the last split

was 55 kg in PR109. Basmati 370

yielded 19 kg seed.

of rice tillers could help in rapid

multiplication of elite and newly

developed cytogenetic male sterile lines

Sequential splitting and transplanting

plant another oilseed crop (rape or

mustard), winter maize, or potato. But

before adoption of rice ratooning in

WS, the benefit-cost ratios of different

cropping patterns summer rice -

ratoon rice - oilseed (or maize or potato

and summer rice - WS rice - oilseed (or

potato or maize) should be

compared.

for hybrid rice production. Small

quantities of experimental hybrid rice

seed also could be multiplied for testing

across several locations in a single

season.

Schematic of single season vegetative propagation o

rice cultivar PR109. Ludhiana, India, 1986 summer



10/40

Foliar application of polyamines,

kinetin, and ascorbic acid and rice

grain filling

M. Anbazhagan, R. Krishnamurthy, and

K.A. Bhagwat, Stress Physiology

Laboratory, Botany Department, M.S.

University of Baroda, Baroda 390002, India

We examined rate of grain filling when

polyamines, kinetin, and ascorbic acid

were applied at preflowering. Three-day-

old pregerminated cultivar GR3 seeds

were sown in 8 kg puddled soils in

plastic pots. Plants were thinned to three

per pot. At 45, 47, 49, and 51 d after

sowing, 10 mol of the polyamines

putrescine, spermidine, and spermine

and ascorbic acid and 2 ppm of kinetin

were sprayed on the test plants. Rate of

grain filling after panicle emergence was

measured gravimetrically.Polyamine, kinetin, or ascorbic acid

brought about early grain maturity

(indicated by early optimum fresh

weight compared to control) (see figure).

Contribution of aquatic tillers to

grain yield in deepwater rice

P. K. Singh, R. Thakur, and N. B. Singh,

Plant Breeding and Genetics Department,Bihar Agricultural College (BAC), Sabour,

Bhagalpur 813210, India

Aquatic tillers in deepwater rice can

contribute considerably to grain yield, if

the water level rises early in the rainy

season and peaks 4-8 wk before

flowering.

To assess the contribution of aquatic

tillers to grain yield, floating rices

Desaria 8 and Jaladhi 1, deepwater rice

Parwapankh, and 2 cultivation

methods direct seeding the last weekof May and transplanting 60-d-old

seedlings the first week of Sep 1983

were studied in a randomized block

design with 3 replications in the BAC

farm tank. Plot size was 9 4 m.

More aquatic tillers were formed in

transplanted than in direct seeded rice

(see table). Direct-seeded rice suffered a

long dry spell during early growth and


Effect of polyamines, kinetin, and ascorbic acid on grain filling in rice cultivar G-R3. Baroda, India.

Initial rate of filling was higher in all treatment, rate of grain filling was

treatments. However, 6 d after panicle higher (as indicated by fresh weight) onemergence, rate of supply from source day 6, but final yield did not differ from

to sink in the ascorbic acid treatment control. In the polyamine treatments,

decreased dramatically, and those plants rate filling was far superior.

yielded less than control. In the kinetin

Aquatic tillers, height, panicle length, and percentage contribution of aquatic tillers to single pla

yield in transplanted (T) and direct seeded (D) deepwater rices. Bihar, India, 1983.

VarietyCultivation

method

Desaria 8 TD

Jaladhi 1 TD

Parwapankh TD

CD

Aquatic Tillertillers height

(no.) (cm)

2.7 80.21.2 279.7

2.5 71.21.5 152.0

4.0 61.21.0 118.6

0.2

Paniclelength

(cm)

14.324.4

16.324.0

16.423.0

0.8

Contribution (%)

of aquatic tillers t

single plant yield

54.926.9

54.913.9

44.2

14.5

7.5

produced more basal tillers. and the shortest (14.3 cm) in

Transplanting was done in 25-30 cm transplanted Desaria 8.

deep water that inhibited production of Contribution of aquatic tillers to grai

basal tillers. To compensate, the plants yield was highest in transplanted rice. produced greater numbers of aquatic

tillers. Highest average number of

aquatic tillers was in transplanted

Parwapankh.

was in direct seeded Desaria 8, the

shortest (61.2 cm) in transplanted excerpts from articles in the IRRN.

Parwapankh. The longest panicle

(24.4 cm) was in direct seeded Desaria 8,

The longest aquatic tiller (279.7 cm) Individuals, organizations, and media ar

invited to quote or reprint articles or


11/40

Genetic Evaluation and UtilizationGRAIN QUALITY

Effect of simulated rain on head rice

yields of varieties under delayed

harvest

F. Cuevas-Prez and A. Hosein, IRTP Latin

America, Centro Internacional de

Agricultura Tropical (CIAT), Apartado

Aereo No. 6713, Cali, Colombia

Rain can cause harvest delays and losses

in rice milling quality. Cycles of high

and low moisture can increase the

proportion of broken grains during

milling.

To test the effect of continuous

evening rain on the milling yield of rice,

we stagger- planted 20 varieties to obtain

simultaneous maturity in Palmira,

Colombia, during 9 May-30 Oct 1986.

Each variety was transplanted in plots of

9 rows, 10 m long and 30 cm apart. At

maturity (20-25% moisture content),

each plot was divided in half with a

plastic curtain extending from ground

level to 30 cm above the top panicle.

Simulated rain was applied to one-half

of the plots with an atomizer operated

at a water pressure of 2 atmospheres,

delivering 60 liters/ h and covering adiameter of 1.5 m. A timing clock

regulated the daily application of

moisture from 1800 to 0600 h for 3 wk.

Both conditions were sampled each

week. Samples were taken at 1100 h,

regardless of environmental conditions.

Grain moisture measurements at harvest

indicated that misting resulted in mean

values 2.5% higher (20.9 vs 18.4%) after

the first week and 1.1% higher (13.0 vs

11.9%) after the second week. Misting

had no significant effect on grain

moisture content at harvest with a delayof 3 wk. Rough rice samples of 125 g

were dried and milled using standard

McGill laboratory equipment.

Head rice yield slopes for each

treatment within each variety were

calculated (see table). Seven varieties

showed similar slopes under simulated

rain and control conditions, whereas the

rest showed faster head rice reduction

Head rice yield slopes of varieties under 3 wk of delayed harvesting and the application of simulate

rain.

Variety Country of Treatmenta Regression equation

b

origin b0 b1 b2 tc

BR IRGA 409 Brazil SR 58.2 0.432 0.010 3.42*

BR IRGA 410 Brazil SR 46.7 1.575 0.015 0.84 n

Ceysvoni Surinam SR 20.8 1.847 0.059 0.26 n

CICA4 Colombia SR 39.2 1.768 0.073 9.56**

CICA7 Colombia SR 36.1 2.569 0.080 0

CICA8 Colombia SR 53.6 1.455 0.029

Diwani Surinam SR 16.4 0.886 0.057 4.33**

EMPASC 104 Brazil SR 42.2 0.755 0.018 7.15**

INIAP7 Ecuador SR 65.5 4.310 0.080 5.45**

INIAP415 Ecuador SR 6 1.9 5.795 0.211 4.70**

INTI Peru SR 58.1 0.083 0.109 1.75 n

IR36 Philippines SR 35.8 3.732 0.109 1.56 n

IR46 Philippines SR 40.4 5.312 0.168 3.56*

IR52 Philippines SR 27.9 3.599 0.122

IR56 Philippines SR 48.0 4.587 0.125 4.42**

IR60 Philippines SR 46.1 2.345 0.027 3.68*

Metica 1 Colombia SR 42.5 1.234 0.006 3.15*

Oryzica 1 Colombia SR 60.3 4.057 0.087 6.60**

Oryzica 2 Colombia SR 53.8 5.419 0.142 2.45 n

Sinaloa A80 Mexico SR 47.0 1.435 0.124 0.02 n

C 51.4 1.635 0.074

C 53.9 1.251 0.012

C 20.2 1.265 0.034

C 36.5 1.732 0.087

C 37.6 1.541 0.031

C 52.7 0.133 0.055

C 29.6 0.668 0.013

C 47.1 2.173 0.158

C 53.2 1.507 0.024

C 59.3 4.439 0.179

C 65 .0 0.016 0.088

C 31.7 2.323 0.051

C 32.7 3.228 0.084

C 22.4 1.258 0.029

C 44.3 2.183 0.019

C 49.3 0.595 0.067

C 46.3 0.280 0.078

C 56.2 1.476 0.007

C 51.6 3.643 0.061

C 53.3 1.502 0.125

a SR = simulated rain, 15 min every hour from 1800 to 0600 h, C = control. b Y = b0 + b1 t+ b2 t2

ns, *, ** = nonsignificant and significant at the 0.05 and 0.01 levels, respectively.

when simulated rain was applied.

Within the first group, varieties INTI

from Peru and Sinaloa A80 from

Mexico seem to have acceptable initial

milling yields and a slow rate of quality

loss, which suggests a certain degree of

tolerance for delayed harvest. Within the

group of varieties with faster rate of loss

with simulated rain, BR IRGA 409

could also be classified as tolerant; suc

varieties could be useful in areas where

delayed harvest is common and millin

quality is demanded. Varieties Oryzica

and INIAP415 represent genotypes wi

acceptable milling yields when harvest

on time, but would be discarded if

milling evaluations included samples

harvested 10-15 d after maturity.

IRRN 12:6 (December 1987) 1

R = 0.95. c b1SR b icHo: =

B2SR b2c


12/40

NCS16

Genetic Evaluation and UtilizationDISEASE RESISTANCE

Evaluation of National Uniform Rice Resistance of rice germplasm to

Yield Trial 1985 against bacterial bacterial blight (BB) at Ludhiana,

blight (BB) in Pakistan India

M. A. Akhtar and M. Akram, Crop Diseases R. K. Goel, R. S. Saini, and A. K. Gupta,

Research Institute, Pakistan Agricultural Genetics Department, Punjab Agricultural

Research Council, P.O. Box 1031, University, Ludhiana (Punjab) 141004, India

Islamabad, Pakistan

We evaluated a germplasm collection of

BB incited by Xanthomonas campestris rites obtained from various places in

pv. oryzae (Ishiyama) Dye occurs in India and internationally for resistance

almost all provinces of Pakistan; it has to BB caused by Xanthomonas

caused considerable yield loss over the campestris pv. oryzae. Each cultivar or

last 4 yr. We tested 19 rice cultivars for line was planted in a 3-m row; standard

reaction to BB at 10 sites in different agronomic practices were followed. At

ecological zones under natural 70 d after sowing (DAS), each line was

epiphytotic conditions in 1985. inoculated with isolate IXO-3, the most

20- 15-cm spacing in a randomized Punjab, using the standard clipping

block design with 4 replications. method. The inoculum consisted of 48-

Recommended agronomic practices h-old growth of the bacterium,

were applied. Disease was measured multiplied on PSA at 25 C, at a

Lines were planted in 4-m2 plots at virulent of 11 isolates identified from the

according to the Standard evaluation

system for rice (SES) 20 d before

harvest.

Lateefy and IR161-1-1-1 showed the

highest mean disease score, DM16-5-1

the lowest (see table).

Response of rice cultivars to BB in Pakistan.

Cultivar Scorea

Lateefy 6.20 h

DR83 5.80 ghSwat II 5.80 ghSwat I 5.40 fgh

Basmati 370-1 4.80 efgh

RGP135 4.80 efgh

DR82 4.60 defgh

KS282 3.80 cdefg

IR6 3.40 cdef

IR42 3.40 bcde

IR16461 3.20 bcde

IR161-1-1-1 6.20 h

IR8-5 2.60 abcd

IR2153-276 2.60 abcdIR1529-ECIA 2.60 abcdIR6-104 1.80 abcJajai 77-1 1.20 abBasmati 370 1.20 abDM16-5-1 1.00 a

a Based on 1980 SES scale. 0-9: 0 = no inci-dence, 9 = 26-50% incidence. Each score is theaverage of 10 locations in different ecological

letter are not significantly different at the 1%zones of Pakistan. Means followed by the same

level by Duncans multiple range test.

Mean lesion length and reaction of rice lines

and cultivars to BB caused by Xanthomonascampestris pv. oryzae. Ludhiana, India.

Mean lesionlength (cm)

70 90DAS DAS

Cultivar or line name

R at 70 DAS and 90 DAS

Palman 579 1.9 2.6

NCS83 0.4 1.4 NCS84 0.4 1.6TCA368 1.0 2.6IR22 1.6 1.0DZ78 1.8 1.8IR46828-B 1.6 2.6IR18350-93-2 1.6 2.6IR21820-154-3-2-2-3 1.9 3.0IR25587-133-3-2-2-2 1.0 1.6IR25916-42-3-3-2-2 1.6 1.6IR27325-63-2-2 1.6 1.6IR29692-65-2-3 1.6 3.0IR31803-32-2 1.9 3.0IR42 1.6 3.0

IR46 1.6 3.0

IR50 1.6 1.6

CR333-6-1 (Jagannath/Mahsuri) 1.6 3.0

IR4744-295-2-3 1.0 3.4

B4032D-MR-1-3-1 1.0 1.6

IR15529-253-3-2-2-2 1.6 2.6

IR15529-256-1 1.0 2.6

IR15795-151-2-3-2-2 1.0 1.6

IR15797-74-1-3-2 1.6 1.6

IR25586-108-1-2-2-2 1.9 3.4

Table continued.

Mean lesion

length (cm)Cultivar or line name70 90

DAS DAS

IR27316-6-2-2 1.9 3.0

IR28154-101-3-2 1.6 3.4

IR2035-117-3 1.6 3.0

IR64 1.6 3.0

R at 70 DAS and MR at 90 DASAmritsari HR 22 1.9 5.6ARC5752 1.6 5.6

ARC10486 1.9 5.6TCA728 1.4 4.0

PR107 1.4 4.0201-1-27 1.9 5.0

RP2068-32-2-3 1.9 5.0RP1801-21-24-20-9 1.9 4.4

IR13475-7-3-2 1.6 4.4

HAU2-165-3-3 1.6 3.

IR13525-43-2-3-1-3-2 1.6 4.0

IR15529-256-1 1.9 4.2

IR19728-9-3-2 1.9 6.

IR25587-67-1-3-3-3 1.6 6.4

IR48 1.9 5.4

NCS211 1.6 5.0

CR333-6-2 (Jagannath/Mahsuri) 1.6 5.0

IR15527-21-2-3 1.6 5.0

IRl8350-93-2 1.9 5.0

HKR26 1.6 5.0

HKR36 1.6 6.4

MR at 70 DAS and R at 90 DAS Nagkayat (HB62) 3.2

Nagra 41/14 2IR46830 (B)2.8 2.CR333-1-1-3 (Jagannath/Mahsuri 4.0 6.2CR333-1-15-2 (Jagannath/ 3.0 3.4Mahsuri)

RP1800-14-11-22-4 2.6 3.0

IR13240-82-2-3-2-3-1 3.4 2.0

IR13538-48-2-3-1 2.4 3.0

IR15429-268-1-2-1 3.0 3.4IR17492-18-6-1-1-3-3 3.6 2.6

IR25588-7-3-1 3.6 2.2

IR25863-35-3-3 3.0 3.4IR28125-79-3-3-2 2.4 3.0

IR28154-101-3-2 3.0 3.0IR54 3.0 3.6IR56 2.6 3.0IR58 3.0 3.0

Bahbolon 3.2 2.4IR17492-18-6-1-1-3-3 3.0 1.0IR21820-154-3-2-2-3 2.6 3.0IR25587-133-3-2-2-2 3.2 1.0

IR27325-27-3-3 3.4 3.0

IR29692-65-2-3 3.0 1.6IR31803-32-2 2.6 1.0

IR32307-107-3-2-2 3.0 1.6HKR30 2.6 1.6IR13475-7-3-2 3.8 3.0IR13458-117-2-3-2-3 2.4 3.0Susceptible check TN1 7.6 14.



13/40

concentration of 109 cells/ mi. resistant (MR); the remaining lines were MR at 70 DAS and R at 90 DAS (see

Lesion length was measured 14 d after classified susceptible. The experiment table). Some sources of resistance

inoculation. Rices with lesion lengths up was repeated at 90 DAS with lines detected here are being used in a

to 25% of that observed on highly classified R or MR in the first test. crossing program for detailed genetic

susceptible TN1 were classified resistant Of 800 lines or cultivars screened, 29 analysis of resistance to X. campestris

(R); those with lesion lengths 26-50% of were R at 70 and 90 DAS; 22 were R at pv. oryzae.

that on TN1 were classified moderately 70 DAS and MR at 90 DAS; 28 were

Genetic Evaluation and UtilizationINSECT RESISTANCE

Sources of resistance to rice thrips

R. Velusamy and K. Natarajamoorthy,

Tamil Nadu Agricultural University

(TNAU), Coimbatore 641003, India

Severe thrips Stenchaetothrips biformis

(Bagnall) damage kills rice varietiesIR20, IR50, Vaigai, and Bhavani in the

seedling stage. We observed differences

in levels of resistance to thrips in the rice

germplasm collections maintained at

Table 1. Sources of resistance to thrips S. bi-formis (Bagnall). TNAU, Coimbatore, India,

1986.

Source

no. PercentageCountry

IndiaUSAFrance

JapanChina

NigeriaNetherlands

TaiwanUSSR

Total

74564

211

11

95

77.95.36.3

4.22.11.0

1.01.01.0

100

Paddy Breeding Station, TNAU. Hence,

we field-evaluated 1,840 traditional rice

cultivars for thrips resistance during Oct

1986.

Seeds were sown in three 1-m-long

rows at 1 seed/cm. Resistant Ptb 33 and

susceptible TN1 checks were sown at

random. TN1 seedlings were completely

killed at 20 d after seeding. Damage

rating was based on Standard

evaluation system for rice 0-9 scale.

This mass screening identified 95

resistance sources, more than 75%

originating in India (Table l), most of

them from Kerala and Tamil Nadu

(Table 2).

Varietal resistance to rice hispareplicated three times. One hundred

hispa adults, collected from the field,

Md. E. Haque, S. L. Durbey, and B. N.

Singh, Rajendra Agricultural University,

Pusa (Sarnastipur) 848125, Bihar. India

Rice hispa Dicladispa armigera Oliv. is

becoming increasingly important in

many Asian countries. Pest attack was

severe in Madhubani, Darbhanga, andSamastipur districts of Bihar, India,

during the 1983 and 1984 wet seasons

Ten elite lines were screened in iron

trays covered with cages in Pusa in 1984

WS. The lines were randomized and

(WS).

were released when the plants were 15

old (4-leaf stage). Percentage of

damaged leaves, number of eggs laid,

number of grubs, and grub survival

percentage were recorded on 10 plants

taken randomly in each replication (see

table).

Type 3, a scented rice variety fromUttar Pradesh, was least preferred by

the insect. The resistance mechanism

seems to be both nonpreference and

antibiosis. Other lines including TCA4

IET6263, and Rajendra Shan 201 were

highly susceptible.

Screening of rice varieties against rice hispa in cages. Bihar, India, 1984 wet season.

Table 2. Sources of resistance to thrips from

India, 1986. Variety

Source

no. PercentageState

Tamil Nadu 33

Kerala 12

Orissa 10Assam 7

Karnataka 5Bengal 3Maharashtra 3Andhra Pradesh 1

44.6

16.213.5

9.56.84.04.01.4

Total 74 100

Damagedleaves Eggs

Grubs

(no./plant) (no./plant)

Grubsurviv

(%)(%)

Radha (BR4)Saket 4

Type 3Pankaj

Rajshree (TCA80-4)

IET6263BR34

Rajendra Shan 201TCA4Sugandha

CD (0.05%)CV (%)

90.074.459.770.1

84.6

87.9

88.593.995.682.9

4.23.7

1.532.170.701.50

2.06

3.13

2.502.802.132.36

0.5014.19

1.52.2

0.72.42.1

3.3

2.52.82.11.5

0.616.2

71.767.562.1

70.9

73.969.5

77.569.767.682.6

4.04.1



14/40

Genetic Evaluation and UtilizationCOLD TOLERANCE

Spikelet sterility in winter rice

P. P. Reddy, K.S. Rao, and N. Kulkarni,Andhra Pradesh Agricultural University,

Agricultural Research Station, Warangal

506007, India

Spikelet sterility appeared at epidemic

levels in farmers' fields of the North

Telangana Zone of Andhra Pradesh in

winter 1983-84. Average minimum

temperatures 20 d before flowering,

from 26 Feb to 4 Mar 1984, were

around 15 C (range 13.7-16.8 C). In

1983, temperatures averaged 21.3 C

during the corresponding period.

the 1983-84 winter season for spikelet

sterility. Entries were planted in 10-m2

plots at 10- 15-cm spacing in a

randomized block design with

4 replications.

Sterile and healthy spikelets on 10

randomly selected panicles in each plot

were counted. Genotypic differences for

spikelet sterility were significant.

We screened 22 rice varieties sown in

Sterility and grain yield of 22 rice cultivarsunder low temperature, 26 Feb-4 Mar 1984.

Sterility

(%)

Grain

yieldVariety

(t/ha)

NLR26706MTU 2400WGL 47877RNR29692WGL 26358WGL 48828WGL 48684WGL 33808Pothana

Tella Hamsa

WGL 48001WGL 6861

MTU6286C73905MTU6910

WGL 39966IR50RNR99181WGL 44645RNR99377IR13525WGL 33343

2.75.66.46.56.77.17.47.78.5

8.7

8.89.39.9

10.0

10.310.412.312.813.214.617.018.1

5.85.85.75.95.55.85.35.45.9

5 .0

5.15.4

5.15.84.6

5.76.05.95.85.85.45.0

Sterility varied from 2.7 to 18%. The RNR29692, and WGL 26358 recordedlowest was in NLR26706 and the highest higher grain yields with low sterility an

in WGL 33343 (see table). can be used in low temperature zonesVarieties NLR26706, MTU2400, and in breeding programs.

Genetic Evaluation and UtilizationDROUGHT TOLERANCE

Response of short-duration rice

cultivars to drought stress

U.N. Dikshit, D. Parida. and D. Satpathy, Dryland Agriculture Research Centre, Orissa

University of Agriculture and Technology,

Bhubaneswar 751003, India

Twenty early-maturing rice cultivars

from different sources were evaluated

during the 1985 and 1986 wet seasons

(WS) (Jun-Oct) under upland rainfed

conditions along with check DR92 (a

released variety) in a randomized block

design with three replications. Seeds

were sown directly in 6.0-m2 plots with a

spacing of 20 cm between rows and

10 cm within rows. Soil preparation,

fertilization (60-60-40 kg NPK/ ha), and

weeding were as in standard, well-

managed plot trials.

Rainfall was normal during 1985 WS

but erratic in 1986, with a 16-d drough

spell. The maturity period of all cultiva

was longer by 2 to 27 d in 1986 because

of severe drought stress (see table). The

long drought spell and the prolonged

maturity period reduced grain yield 10-

91%. A significant and positive

correlation (r = 0.727) was obtained

between maturity prolongation and yie

reduction due to drought stress.

Performance of rice cultivars under drought stress. Bhubaneswar, India, 1985-86.

Days to maturity Yield (t/ha)

Cultivar1985 1986 1985 1986 Yield reduction (%

DR83-1DR83-2OR165-93-15ORKM6DR83-16OR165-97-15IET7613

IET7566DR83-3

OR165-86

-12

ORKM4

IET7564IET7617IET7261IET7635IET7625IET7633IET7614IET7911DR92 (check)

CD (0.05)

9191899498908989

90

909192

102102104

105114102102

91

104104104110110112100105109

113105119

116114118120116112112102

2.72.7

2.42.32.12.12.12 .02.0

2.01.9

1.71.41.31.31.21.00.70.22.60.3

1.51.30.30.80.80.20.50.7

0.5

0.40.6

0.2

0.60.8

0.50.80.90.70.21.20.2

4552886562917665

75

806988

5837623410

54



15/40

The yield differences among the Table 2. Effect of chlormequat chloride on rice yield. Semiliguda, Orissa, India, Jun-Sep 1979.

entries were significant in both years.

DR cultivars recorded higher yields than chlorideIET or OR cultivars. DR83-1 and

DR83-2 in both normal and drought

years outyielded the other entries,0 (water) 2.0 1.5

500 1 25 2.1 1.8

indicating their drought tolerance 1000 1 25 2.2 1.8

capacity.500 2 25,40 2.4 1.9

1000 2 25,402.3 1.8

0.3 0.1

Chlormequat Sprays Time Grain yield (t/ha)

(no.) of spray

(ppm) (d after germination) Parijat Subhadr

CD (0.05)

Responseofrainfed upland rice to

chlormequat chloride (Table 1). After germination, higher when 500 ppm chlormequat

chlormequat chloride at 500 and chloride was sprayed twice (Table 2).B. K. Ghosh and S. K. Sahu, Plant 1,000 ppm was sprayed once or twice. The response was higher in Subhadra Physiology and Soil and Agricultural Both varieties yielded significantlyChemistry Departments, College of

than in Parijat.

Agriculture, Orissa University of Agriculture

and Technology, Bhubaneswar 751003,

Orissa, India Genetic Evaluation and Utilization

Upland, rainfed rice yields in Orissa are

very low because of continuous drought.The use of a growth retardant on rice

may improve crop yield by enabling the

plant to resist drought through root

proliferation.

We studied the effect of chlormequat

chloride on the grain yield of rice at the

Regional Research Station, Semiliguda,

in Jun-Sep 1979. The soil was a clay

loam (Ochrept) with pH 5.5, 0.852%

organic matter, 9.5 kg available P/ha,

cation exchange capacity 8.5 meq/100 g

soil, and water-holding capacity 45%.

Parijat (100 d duration) and Subhadra

(90 d) were the test varieties.

The crops suffered from intermittent

drought at various growth stages

Table 1. Stages of growth and drought spellssuffered by the crop. Semiliguda, Orissa, India,Jun-Sep 1979.

Plant ageDrought

conditions

SeedlingGermination to day 4 No droughtDay 5 to 19 Drought

VegetativeDay 20 to 40 No droughtDay 41 to 52 DroughtDay 53 No drought

ReproductiveDay 54 to 60 DroughtDay 61 to 62 No drought

Day 63 to 68 DroughtDay 69 No drought

Flowering and ripeningDay 70 until harvest Drought

ADVERSE SOILS TOLERANCE

Screening for zinc deficiency

tolerance in rice

grown in 15-m2 plots in 3 replications.

The symptoms were severe 25-30 d afte

transplanting. The soil was a light,

B. N. Singh and R. Sakal, Rajendra

Agricultural University, Pusa (Samastipur),

Bihar, India

Zn deficiency is becoming a major

nutritional problem limiting rice yield.

Genetic variability for tolerating it exists

in rice genotypes. During the 1985 wet

season at Pusa, severe Zn deficiency was

observed in a varietal trial of 16 entries

extremely calcareous (free CaCO3 39%

sandy loam (organic C 0.48%, pH 8.6,

EC 0.50 dS/m).

Scoring was based on percentage of

hills affected in a plot (see table). Zn

content of the third leaf from the top

(five leaves from each replication,

bulked) was determined with an atomi

absorption spectrophotometer. Toleran

varieties had higher Zn concentration i

Zinc tolerance in rice varieties. Bihar, India, 1985 wet season.

IETno.

DesignationScorea Zn concentratio

Cross(ppm)

3279

76147613614872547564

7616

6223

CR126-42-2

NC1626RP1451-1712-4319RP1670-1418-2205-1582TNAU6464TNAU(AD)103RP1667-301-1196-1562

RP1888-4259-1529-126IR25588-7-3-1Pusa 4-11

Pusa 33Pusa 2-21ES29-5-3RAU4004-127CR222-MW10IR25890-82-5-3

Dungansali/IR8 3Selection from land races 1

Rasi/Fine Gora 3M63-83/Cauvery 3Bala/CO 13 3Tiruveni/Amravathi CO 3 3

IRAT8/N22 7

RP79-5/Tella Vadlu 5

Tadukan/IRB 7

Improved Sabarmati/Ratna 7IR8/TKM6 7

99

MTUl5/Waikoku 9RP825-714-ll/CR113-32// 9IR9129-209-2-2

IR19657-37-3/IR9129-209-2-2 7

2838

2924

28

2716

221416

191713121313

aBased on percentage of hills affected in a plot: 1 < 1%, 3 = 1-5%, 5 = 6-25%, 7 = 26-50%, 9 = 5100%.



16/40

the leaves than susceptible varieties. RAU4004-127, and IR25890-82-5-3 had criterion for screening a large number NC1626, IET3279, IET6148, and over 95% affected hills. The Zn content lines and can be used for geneticIET7614 were tolerant. ES29-5-3, in the third leaf may be taken as a studies.

Genetic Evaluation and UtilizationTEMPERATURE TOLERANCE

Cold tolerance in dry season rice for

deepwater areas of north Bihar, India

B. N. Singh and S. P. Sahu, Plant Breeding

Department, Rajendra Agricultural

University, Pusa, Samastipur, Bihar 848125,

India

We have studied growing irrigated rice

in deepwater and low-lying areas during

the Dec-May dry season since 1980. In

the eastern part of Bihar, adjoining West

Bengal, semidwarfs Jaya, Pusa 2-21, and

local cultivars are grown on about

10,000 ha. In some regions, the

temperature drops to 5 C the last week

of Dec to early Jan. Those areas need

cold-tolerant lines.

laid out during the 1984 dry season.

Entries were seeded 27 Oct 1984 by the

wet method and transplanted 22 Dec in

a deepwater plot puddled with residual

water. Plot size was 9.4 m2 in a

randomized block design with 2replications. P and K at 26 and 25

kg/ha was basally applied and 40 kg

N/ ha was topdressed at tillering and at

panicle initiation. Six irrigations were

given as necessary. Temperature reached

5 C the last week of Dec and many

varieties did not survive. However, 8

varieties had more than 50% survival

An experiment with 20 genotypes was

Table 1. Cold tolerance in different rice geno-

types. Bihar, India, 1984-85.

DesignationSeedlingsurvival

(%)

IET7617, IET7613, IET6223 81-100Rasi, CR251-55-54-1, IET7614 71-80IET3279 61-70Saket 4 51-60Br 34, RD201, Rewa 353-1 41-50ES 21-2-5 31-40IR19743-25-2-3 21-30Pusa 2-21, Sita, IET7564, Rewa 353-2 11-20IET6148, IET7970 0-10

Table 2. Grain yield of promising cold-tolerant lines. Bihar, India, 1985-86 dry season.

Grai

(t/ha

yielDesignation cross

CR126-42-2RP1451-1712-4319RP1888-4259-1529-126CR222-MW10RasiCR125-55-54-1RP1670-1418-2205-1582Saket 4 (check)

CD (0.05)CV (%)

Dungansali/IR8Rasi/Fine GoraRP79-5/Tella VadluMTU15/WaikokuTN1/CO 29WH18/MTU17//TN1M63-83/CauveryTKM6/IR8

1.01.10.90.70.60.90.80.6

0.127.6

(Table 1). Br 34, a photoperiod-sensitive

variety, did not flower. All other

varieties flowered and were harvested in

May.

The eight cold-tolerant lines were in

yield trials during the 1985-86 dry

season. Each entry was planted in 24-m2

plots at 20- 15-cm spacing in a

randomized block design with 3

replications. The nursery was sown 25

Oct 1985 by the wet method and

transplanted 23 Dec 1985 after plots

Genetic Evaluation and Utilization

DEEP WATER

Sudha, a new deepwater rice

variety in Bihar, India

B. N. Singh, S. P. Sahu, and R. Thakur,

Rajendra Agricultural University, Pusa,Samastipur, Bihar 848125, India

Sudha, the popular name given TCA72

(IET8977), has been released for rice

areas with up to 100 cm water depth in

Bihar. It can be direct seeded in

deepwater areas in Mar or transplanted

or direct seeded in May-Jun in rainfed

lowland waterlogged areas (25-50 cm).

were puddled with the receding water o

deepwater plots. Fertilizer was 80-18-17

kg NPK/ ha. One-fourth N and all P

and K were applied basal; one-half N

was applied at maximum tillering, and

one-fourth N at panicle initiation.

Harvest was at the end of May.

Yield data show RP1451-1712-4319

and CR126-42-2 as promising (Table 2

Brown leaf spot was a problem at the

seedling stage; stem borer at

transplanting and harvesting.

Sudha was selected for its non-

shattering grain type and resistance to

tungro and sheath rot (Table 1). It has

drought tolerance at vegetative and

reproductive stages. It is 150-200 cm taldepending on water depth. It is

photoperiod-sensitive, flowering around

22-25 Oct. Grain is long and slender

(length 7.37 mm, width 2.37 mm,

1ength:breadth 3: l), and 1,000-grain

weight is 27 g. The husk is straw colore

and the kernel light red.

moderately resistant to bacterial leaf

It is resistant to leaf spot and



17/40


18/40

Genetic Evaluation and UtilizationHYBRID RICE

Retardation of heading in male

sterile and restorer lines using

paclobutrazol

Rui-chi Pan and Guang- jian Liang, Biology

Department, South China Normal

University, Guangzhou, China

Flowering synchronization in parent

plants is a key problem in increasing

hybrid rice seed yields. Heading can be

promoted by GA3 treatment, but no one

has reported delay in heading by growth

regulators.

We sprayed an aqueous solution of

75 ppm paclobutrazol at 11 ml/m2 on

rice plants at the pollen mother cell

formation stage of a cytoplasmic male

sterile line (Zhen Shan 97A) and a

Table 1. Effect of 75 ppm paclobutrazol solution on the heading of cytoplasmic male sterile line

and restorer line of rice, Guangzhou, China, 1985-86.

LineBeginning of heading a

Sowing date Treatment date

restorer line (IR64) growing in the field.

Endogenous GA3 content wasdetermined by leaf sheath bioassay.

Paclobutrazol treatment reduced

endogenous GA3 content in panicles

(paclobutrazol is an antigibberellin).

After treatment, elongating rate of the

topmost internode decreased. Beginning

of heading was delayed 2-4 d with

1 treatment and 4-6 d with a second

treatment 5 d after the first treatment

(Table 1).

counteracted the retardative effect of

Foliar spray of GA3 solution

Control

Restorer line

IR64 11 Mar 1985 4 JunIR64

14 Jun3 Jul 1986 30 Aug 8 Sep

Cytoplasmic malesterile line

Zhen Shan 97A 12 Apr 1985Zhen Shan 97A 17 Jul 1986

2 Jun 12 Jun4 Sep

Zhen Shan 97A14 Sep

7 Apr 1986 29 May b

Zhen Shan 97A9 Jun

7 Apr 1986 29 May c 9 Jun

3 Jun d

Treated paclobutrazol and the plants recoveredtheir height or were even taller (Table 2

16 Jun The pollen in treated plants developed10 Sep normally, so did the seeds of the treated

and the next generation.

15 Jun

18 Sep differentiation could adjust12 Jun synchronization of flowering in male15 Jun sterile lines and pollen parents and

Using paclobutrazol spray at panicle

should be conducive to higher crosseda 10% of the panicles have exserted. b First treatment, no second treatment. c First treatment.d Second treatment.

seed set.

Table 2. Effect of paclobutrazol (Pac) and GA3 on internode lengtha

of mature rice plant Zhen Shan 97A. Guangzhou, China, 1986.

Treatment Topmost internode 2d internode 3d internode 4th internode 1-4 internodes

lstb 5 d later Length %

(cm)

0 0 20.0 b 100

75 ppm Pac 0 16.6 c 8375 ppm Pac 75 ppm Pac 10.2 d 51

75 ppm Pac 30 ppm GA3 20.2 b 10175 ppm Pac 50 ppm GA3 22.5 a 112

Length %

(cm)

13.0 b 100

12.9 c 846.5 d 50

13.3 b 102

23.1 a 178

Length % Length % Length %

(cm) (cm) (cm)

7.1 b 100 3.4 b 100 43.4 b 1006.6 b 93 3.4 b 100 37.5 c 836.0 b 84 2.8 b 83 25.8 d 596.9 b 97 3.0 b 90 43.4 b 100

25.2 a 354 11.3 a 337 82.1 a 189

a Means followed by a common letter are not significantly different at the 5% level by Duncans multiple range test. b Conducted at pollen mother ceformation stage.

Evaluation and use of male sterile

systems in Mekong Delta, Vietnam

Nguyen Van Luat and Pham Cong Voc,

Cum Long Delta Rice Research Institute

(CLRRI), Oman, Hau Giang, Vietnam

We evaluated in 1983-86 10 male sterile

(A) lines and their corresponding

maintainer (B) lines introduced from


China and IRRI.

row ratio of 2:4. Sowing times were

adjusted to synchronize flowering.

Seedlings were transplanted at 20- 15-

cm spacing and received 70-40-30 kg

NPK/ ha. Rope pulling was used to

supplement cross pollination but flag

leaves were not clipped and GA3 was

not applied.

A and B lines were transplanted in aAgronomic traits and disease and

insect reactions were recorded.

Percentage spikelet sterility was

determined by bagging five panicles

from three plants of each A line at

heading in the greenhouse. To estimate

outcrossing pollination rate, 20 plants

were harvested.

V20A, V41A, Zhen Shan 97A, and

Yar ai zhao A did not perform well in


19/40

(%)

cells/ml, using the clipping technique.inoculate male sterile (A) lines V20A

Length of lesion was measured 3 wk

after inoculation on a sample of 20

leaves/plot.

Cytoplasm affected the expression o

BB reaction significantly and interacti between nucleus and cytoplasm was

detected (see table). A lines were less

susceptible than the B lines.

and Zhen Shan 97A, and their

corresponding maintainer (B) lines

during the first growing season of 1985.

The test was in a randomized complete

block design with three replications.

Plants were inoculated at booting with a

bacterial suspension of about 109

Characters of male sterile lines evaluated in 1983-86 at CLRRI, Omon, Hau Giang, Vietnam.

Seed setting (%) Disease reactiona

Male sterile Maintainer Maturity Height Tillers PanicleSpike1et

(A) (B) (d) (cm) (no.) exsertionsterility

Wet Dry Wet season Dry seas

season seasonBB ShB ShR B

V20AV41AZhen Shan 97A

MS519AYar ai zhao A

IR46829AIR46830AIR46831AIR48483A

(IR54752A)IR21845-90-3A

V20 89V41 95Zhen Shan 97 93

Yar ai zhao 97IR24 120IR19792-15-2-2 95IR19807-21-2-2 102Jikkoku Surranai 52-37 110

MS365 110

(IR54752B)IR21845-90-3 140

CV (%)LSD (0.05)

75 1080 978 9

77 895 1275 1476 1685 1880 18

110 12

12.6 15.714 3

FairPoorPoor

PoorFairFairFairFairFairFair

100100100

958597

10092

10095

2 21 5 7 5 26 18 3 7 5 32 26 5 7 3 5

9 27 5 7 5 59 17 3 5 3 49 13 5 7 5 37 30 5 5 58 20 3 5 3 66 28 3 5 3 8

10 19 5 5 3

a Field evaluation. b Evaluated in 1986 blast nursery according to IRRI Standard evaluation system for rice scale.

terms of plant type and reactions to with heavy tillering. They were resistant showed better adaptability to local

diseases, especially to sheath blight to blast (Bl) but moderately susceptible conditions than the A lines from China

(ShB) (see table). But they showed to bacterial blight (BB) and sheath rot However, V20A, IR46830A, IR48483Ahigher spikelet sterility. (ShR) in the field. and IR54752A grew reasonably well an

IRRI improved lines IR46830A, Seed setting in A lines was lower in could be used to develop rice hybrids i

IR48483A, and IR21845-90-3A the wet season than in the dry season. Vietnam.

(IR54752A) had acceptable phenotype In general, IRRI improved A lines

Susceptibility of A lines and B lines

to bacterial blight (BB)

R.C. Yang, Fujian Agricultural College,

Fuzhou, China

Fifteen isolates ofXanthomonas

campestris pv. oryzae were used to

Susceptibility of A and B lines to BB. a Fuzhou, China, 1985.

Lesion length (cm)

Isolate Isolate no.group

III 83476-2IV 79113-4III 83500-1IV 83505-1

III 82409-3III 83498-1

IV 82443-1III 82400-1IV 80153-1III 83470-2II 81267-1III 83485-3III 79048-1I 81259-7I 81317-3

Zhen Shan 97 V20

A B A-B a A B A-B

26.9 29.4 2.5* 26.527.1

28.828.5 1.4

26.025.8

28.226.1

2.2** 28.725.6 28.1

27.8 1.0 2.5* 26.6

25.1

27.3

27.0 1.9**

0.7

21.223.1 26.8 22.9 25.0

24.03.7*

2.8*

22.8 26.2 3.4* 24.6 25.12.1 **

23.50.5

27.3 3.8* 21.6 23.1 1.525.3 26.5 1.2 23.1 22.923.0 24.4

0.2 1.4 20.8 21.7 0.9

23.5 27.1 3.6* 21.0 22.923.4

1.9**23.4 0.0 23.8

21.5 24.722.6 1.2

9.0 3.2* 16.1 17.9 1.8**

9.7 0.7 9.97.3

10.78.1 0.8 7.5 7.6 0.1

2.3*0.9

0.8

The International Rice Research News-

letter (IRRN) invites all scientists to

contribute concise summaries ofsignificant rice research for publication.

Contributions should be limited to oneor two pages and no more than two

short tables, figures, or photographs.

Contributions are subject to editing

and abridgment to meet space

limitations. Authors will be identified

by name, title, and research organizatio

a Significance at the 1% (**) and 5% (*) levels.



20/40

Yield evaluation of F1 hybrids in the

Mekong Delta, Vietnam

Pham Cong Voc and Nguyen Van Luat,

Cuu Long Delta Rice Research Institute

(CLRRI), Omon, Hau Giang, Vietnam

We evaluated 29 FI hybrids introduced

from IRRI and 60 FI hybrids developedat CLRRI in yield trials with 3

replications 1983-86. Single seedlings

were transplanted at 22 d, at 20- 15-

cm spacing in 2- 2.5-m plots.

Fertilizer was 40-30 kg PK/ha applied

as basal and 75 kg N/ha in 3 equal

splits: at puddling, tillering, and panicle

initiation.

Nine percent of the combinations

yielded significantly higher than check

varieties NN3A and NN4B. The

promising F1 hybrids had 10-33%

positive heterobeltiosis and 11-22%standard heterosis (see table).

Yield, heterobeltiosis, and standard heterosis of some promising F1 hybrids identified at CLRROmon, Hau Giang, Vietnam, 1986.

Year F1 hybridYield Heterobeltiosis Standard heterosi

(t/ha) (%) (%)

1983-84 V20A/NN4B97A/NN4BNN4B

CV (%)

LSD (0.05)1984-85 IR48483A/IR36

IR48483A/IR54NN3A

CV (%)LSD (0.05)

1985-86 IR46831A/OM90NN7A

CV (%)LSD (0.05)

1985 V20A/NN3ANN3A

CV (%)LSD (0.05)

1986 IR46831A/OM90NN7ACV (%)LSD (0.05)

Dry season

6.55.54.8

15.3

1.15.85.54.8

16.70.4

5.34.4

13.00.5

Wet season6.65.2

12.70.6

6.25.2

13.60.6

33.3917.57

19.9110.00

21.31

26.67

17.73

16.1 110.50

19.9114.10

22.27

26.67

17.78

Genetic Evaluation and UtilizationTISSUE CULTURE

Induction of productive semidwarf

mutants of Basmati rice

M.S. Sajjad and M. A. Awan, NuclearInstitute for Agriculture and Biology,

Faisalabad, Pakistan

Basmati rices are prized for their good

cooking quality and aroma. Basmati

370, isolated from the local

germplasm, currently is cultivated

predominantly in Punjab Province. The

cultivar is matchless in cooking quality

and aroma, but is tall and has weak

straw, so that it is unable to respond to

fertilizer and to withstand lodging.

Hybridization involving the Dee-Geo-

Woo-Gen dwarfing gene source has

been tried to modify these two inherent

characters.

Induced mutation could be another

approach. We induced semidwarf

mutants of Basmati 370 during 1980.

with 14% moisture content were

exposed to 0, 15, 20, and 25 kR from a

Healthy uniform seeds of Basmati 370

Performance of semidwarf mutants and parent Basmati 370 in micro yield trial. a Faisalabad, Pakitan, 1983-84.

Plant Productive Panicle Grains Panicle 1,000- Yield

(t/haMutant orheight tillers length (no./panicle) fertility grain wt

variety (cm) (no./plant) (cm) (%) (g)

Basmati 370 177.0 a 9.3 b 30.6 a 112.3 a 85.3 a 21.3 a 3.6 SDM18 132.8 b 10.9 a 28.0 c 121.6 a 89.1 a 19.1 b 4.5 a

(15 kR)SDM20 133.2 b 11.8 a 28.3 c 119.5 a 88.9 a 19.3 b 5.1 a

(15 kR)SDM22 134.1 b 11.3 a 29.2 b 127.3 a 89.1 a 19.3 b 5.2 a(15 kR)SDM24 132.8 b 11.8 a 29.2 b 127.4 a 89.6 a 19.3 b 5.4 a(20 kR)SDM25 131.5 b 11.3 a 28.3 c 124.3 a 89.5 a 19.1 b 5.2 a(20 kR)SDM38 131.8 b 12.0 a 28.4 c 118.0 a 89.3 a 19.5 b 5.2 a(25 kR)

a In a column, figures followed by the same letters are not significantly different at the 5% level significance by DMRT.

60Co source (5,000 seeds/ treatment). seedling/ hill, 20- 20-cm spacing.

Seedlings were transplanted 1/hill at Some semidwarf mutants were

15- 15-cm spacing to suppress profuse selected and their breeding behavior

tillering. Three first-emerging panicles studied during 1982-83. True-breeding

per plant were harvested and bulked by mutants (gross plant size 8 m2) were

treatment. The M2 was grown at 1 tested in a micro yield trial during 1983



21/40

84, in a randomized complete block length and 1,000-grain weight were higher number of productive tillers pe

design with 4 replications. Seedlings significantly inferior. Mutant strains plant.

were transplanted at l/hill, 20- 20 cm were similar in grains per panicle and All the mutants exhibited semidwar

spacing. Fertilizer was 80-40-0 kg panicle fertility. Their yield potential plant posture along with higher yieldin

NPK/ ha. was 25-51% higher than that of Basmati capability, and may be used directly a

All mutant lines were 24-26% shorter 370. The attribute of mutant lines that indirectly as new gene sources for sho

than Basmati 370 (see table), but panicle may enhance yield potential seems to be culm for Basmati rices.

Pest Control and ManagementDISEASES

Effect of sclerotia size of

Rhizoctonia solanion infectivity on

rice plants

Yin Shangzhi and T. W. Mew, IRRI

Sclerotia of R. solani, the causal

organism of rice sheath blight (ShB), are produced in large numbers on infected

plants and often drop to the soil after

harvest. Because they can survive for a

Table 2. Effect of R. solani sclerotia size andnumber on infectivity on rice plantsa in the

greenhouse. IRRI, 1985.

Numberinoculated

Lesionlength

Lesionnumber

(mm)

0.7 0.7 mm1 0 02 0 03 0 04 9.5 2.95 10.4 5.2

1.2 to 5.1 and average lesion size from

9 4 to 19 5.6 mm as sclerotia size

increased from 1 1 to 2 2 mm

(Table 1). On seedlings in pots, averag

lesion number increased from 0 to 31.

and lesion length from 0 to 23.7 mm,

sclerotia size increased from 0.7 0.7

2 2 mm and sclerotia numbers fromto 5 (Table 2).

long time, they tend to accumulate in 1 1 mm

the soil and are a primary source of

inoculum. We examined sclerotia size2 11.4 5.13 14.0 8.2

1 10.5 4.3 Time of spraying to control sheath

(ShR)

and distribution in a naturally infested

field and the effect of sclerotia size and

number on infectivity of rice plants.

Surface soil from a ShB-infested

ricefield was collected after harvest and

processed in the laboratory. The

sclerotia recovered were measured andgrouped by size. The effect of sclerotia

size and number on infectivity was

tested by inoculating detached rice

leaves and rice seedlings with different

size and numbers of sclerotia recovered

from soil or grown on potato dextrose

agar (PDA). Sclerotia produced

naturally, sizes 1 1, 1.5 1.5, 1.8

Table 1. Effect of R. solani sclerotia size oninfectivity on detached rice leaves.a IRRI, 1985.

Sclerotia sizeb Lesionsc Lesion sized

(mm) (no.) (mm)

2 2 5.1 19 5.61.8 1.8 4.3 17 4.51.5 1.5 2.8 13 4.11 1 1.2 9 4

a Data collected 4 d after inoculation. bSclerotia

counted on each leaf blade inoculated: 2 repli-recovered from naturally infested soil. cNumher

cations with 10 blades each. dAv size lesionmeasured.

45

1

2345

12345

15.216.5

1.5 1.5 mm17.819.220.220.620.7

2 2 mm20.621.122.022.223.7

11.813.6

12.414.916.317.017.4

10.314.522.528.431.6

aRice cultivar IR36

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International Rice Research Newsletter Vol12 No.6

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