International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Improved technologies on yam for enhancing
livelihood of farmers in Africa
-Progressed activities & further challenge-
Hidehiko KIKUNO (Yam physiologist)
International Institute of Tropical Agriculture
(IITA) Ibadan, Nigeria
14 October 2010
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Seed yams required to plant one hectare
Seed tubers
Stagnation of yam production could be mostly attributed to high production
costs.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Seed Tubers of Yam
• Expensive (as much as 63% of total variable cost)
• Bulky to transport
• Low multiplication rate in the field (1:5 – 1:10)
• Take time to release new varieties and breeding period
• Potential carriers of pests, pathogens and nematodes
Need for rapid methods for mass propagation
of high quality and healthy seed tubers
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Improve propagation
techniques
Development of meristem culture
protocol for yam germplasm
management
Off-season yam
cropping system
(Seed tuber from
vine propagation)
Healthy seed tuber production
system on yam through vine
propagation
Other research
activities used
seedlings from
vine propagation
as new tool
Capacity building
Network Collaboration
Communication
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Improve propagation
techniques
Development of meristem culture
protocol for yam germplasm
management
Off-season yam
cropping system
(Seed tuber from
vine propagation)
Healthy seed tuber production
system on yam through vine
propagation
Other research
activities used
seedlings from
vine propagation
as new tool
Capacity building
Network Collaboration
Communication
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Low regeneration rate of shoots from meristem
IITA has been maintaining germplasm collection
of yams (more than 3,000 accessions of
Dioscorea spp.) for distribution to NARIs
In vitro yam germplasm conservation
at IITA genebank
Meristem culture is an essential techniques
for virus free material and cryopreservation
for long term conservation
Obstacle for clean germplasm collection and distribution
Obstacle of meristem culture on yam
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Combination of plant growth regulators (NAA, BAP and GA3)
Basal media: MS, LS and B5 media
NAA (μM) BAP (μM) GA3 (μM)
0.05 0.20 0.00
0.05 0.20 0.30
0.05 0.60 0.00
0.05 0.60 0.30
0.10 0.20 0.00
0.10 0.20 0.30
0.10 0.60 0.00
0.10 0.60 0.30
0.50 0.20 0.00
0.50 0.20 0.30
0.50 0.60 0.00
0.50 0.60 0.30
10 meristems x 12 treatments = 120 x 3 media = 360 x 3 reps
= 1,080/accession (5meristem/petri-dish), 36 combinations
Materials and methods of meristem culture
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Plant materials
(IITA Screen house)
Sterilization method
70% ethanol for 1 minute
1% sodium hypochlorite solution
for 15 minutes
meristem
Meristem on medium
Procedure of meristem culture on yam
TDr 95/18544 (White yam)
TDa 98/01183 (water yam)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
NAA BAP N (%) N (%) N (%)
0.05 0.2 30 70.0 ab 29 55.9 abcd 21 85.7 a
27 55.2 abcd 29 58.9 abcd 21 76.0 a
0.6 30 73.3 a 30 26.7 e 21 76.0 a
30 73.3 a 30 63.3 abc 19 77.7 a
0.1 0.2 29 63.3 abc 30 66.7 ab 21 66.7 a
30 40.0 cde 30 51.8 abcd 21 90.7 a
0.6 30 73.3 a 25 33.3 de 21 71.7 a
25 66.7 ab 30 50.0 abcde 21 85.7 a
0.5 0.2 30 63.3 abc 25 66.7 ab 20 90.3 a
30 46.7 bcde 25 63.3 abcd 21 85.7 a
0.6 29 69.8 ab 30 53.3 abcd 21 62.0 a
29 58.1 abcd 30 40.0 cde 21 61.7 a
349 62.8 A 343 52.5 B 249 77.5
GA3
Concentration of plant
growth regulator (μM)
0.3
0.0
0.3
0.0
0.3
0.0
0.3
0.0
0.3
0.0
0.3
0.0
MS
Medium
LS B5*
Different letters imply significant difference at 5%
level
*B5 medium was separately
tested
Effect of plant growth regulator and media on shoot
regeneration (%) of (TDr 95/18544) 8 weeks after
meristem culture
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
NAA BAP N (%) N (%) N (%)
0.05 0.2 30 33.3 bc 30 40.0 b 30 80.0 a
0.3 29 18.0 bcdefg 29 23.7 bcde 30 30.0 bcd
0.6 0.0 30 20.0 bcdefg 30 23.3 bcdef 30 3.3 g
0.3 29 6.7 efg 30 13.3 cdefg 30 3.3 g
0.1 0.2 0.0 30 23.3 bcdef 29 32.0 bc 30 66.7 a
0.3 28 0.0 30 3.3 g 25 36.7 bc
0.6 0.0 25 3.3 efg 29 6.7 efg 30 0.0
0.3 28 3.3 fg 30 0.0 30 0.0
0.5 0.2 0.0 30 16.7 cdefg 30 10.0 defg 29 20.0 bcdefg
0.3 29 3.3 fg 30 0.0 29 34.0 bc
0.6 0.0 30 10.0 defg 30 6.7 efg 30 0.0
0.3 29 0.0 30 0.0 30 0.0
347 11.5 B 357 13.3 B 353 22.8 A
GA3
0.0
Concentration of plant
growth regulator (μM)
Medium
MS LS B5
Different letters imply significant difference at 5% level
Effect of plant growth regulator and media on shoot
regeneration (%) of (TDa 98/01183) 8 weeks after
meristem culture
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Accession Media
MS LS B5
TDr 95/18544 1.6A 4.7B 0.0
TDa 98/01183 10.8A 8.7A 0.8B
Different letters imply significant difference at 5% level
Effect of media component on callus formation(%)
of yam 8 weeks after planting
D. alata 8 weeks after planting
(MS+NAA 0.5μM,BAP 0.6μM)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
NAA BAP GA3 N (%)
0.05 0.6 0 37 92.0 a
1.07 0.67 0.23 39 54.0 b
Concentration of plant growth
regulator (μM)
Comparison of media component with PGRs between
IITA current media and best media with PGRs
combination for meristem culture
(The best component under this trials)
MS media + NAA 0.05μM + BAP 0.6μM
Effect of plant growth regulator and media on shoot regeneration
(%) of D. rotundata (TDr 95/18544 ) 8 weeks after planting
Different letters imply significant difference at 5% level
(Current media component used at Gene bank)
MS media + NAA 1.07μM+ BAP 0.67μM+ GA3 0.23μM
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
1) Best media component with PGRs combination showed
higher rate of regeneration compared with current media
component to have been used at IITA Gene bank
2) Application of GA did not enhance regeneration of shoot and
3) B5 media showed less callus formation compared with MS
and LS
For stable conservation of germplasm of yam, it is best to use a
media which has less callus and high regenereation of shoot.
Although B5 media has a potential, further trials to test on more
species and accessions for making the protocol are needed.
Conclusion
Y. Hasegawa, H. Kikuno, B. Gueye, D. Dumet, O. Oyelami, H. Shiwachi and H. Takagi. (2010)
Preliminary screening of growth regulator and mineral combination to establish in vitro
meristem regeneration protocol for yam genebanking. Japanese Society for Tropical
Tropical Agriculture, Research for Tropical Agriculture Vol. 3, Extra issue 2, pp115-116.
October 09-10.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Improve propagation
techniques
Development of meristem culture
protocol for yam germplasm
management
Off-season yam
cropping system
(Seed tuber from
vine propagation)
Healthy seed tuber production
system on yam through vine
propagation
Other research
activities used
seedlings from
vine propagation
as new tool
Capacity building
Network Collaboration
Communication
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Healthy seed tuber
production system on yam
through vine propagation
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
1) High multiplication (more than 50 times)
(Depend on plants, variety, growth, and season)
2) Elimination of nematodes from tubers
(Clean land without nematodes is needed for culture)
3) To reduce usage of tubers which can use for foods or
seed tubers for next cropping season
4) To be able to produce mini-tubers with high sprouting
rate and uniformity of sprouting compared with those
of mini setts
Advantages of vine propagation of yams
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
5) To be able to produce tubers (seed or ware) through
year round, leading off-season yam cropping
6) To be able to produce healthy seed tuber production
system (Availability of seedlings from tissue culture
materials propagated from meristem)
7) Rapid propagation of high yield improved varieties at
the beginning stage of dissemination to NARS or
farmers
8) Usage of research tools (i.e. screening materials,
rapid multiplication of breeding line or F1 plants)
Cond.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Important technical points for
vine propagation studied
1)Healthy plant materials as mother plants of
vine cuttings
2) Type of planting materials
3) Physiological age of mother plants
4) New shoots formation from vine cutting
5) Timing of vine propagation (excising &
culture)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Important technical points for
vine propagation
1)Healthy plant materials as mother plants of
vine cuttings
2) Type of planting materials
3) Physiological age of mother plants
4) New shoots formation from vine cutting
5) Timing of vine propagation (excising &
culture)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Meristem culture
Established plants in screen house
Seedlings acclimatized
In vitro plantlets
Preparation of vine cuttings
Production system for healthy plant materials as mother
plants of vine cuttings
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Cond.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Effect of flowering & virus infection on the survival rate
Of vine cutting of white yam
Clone Survival %
Flowering
(No=0,
Yes=1)
Score of virus infection
(Nil=0,Low=3, Middle=6,
High=9)
Amula 80.0ab 1 3
TDr 95/19177 62.2bcde 0 3
TDr 95/18544 55.6cdef 0 3
TDr 93-31 75.6abc 0 3
TDr 99/02789 37.8 1 6
TDr 96/00604 82.2a 0 0
TDr 97/00925 17.8 0 6
TDr 96/01818 15.6 1 6
Meccakusa 48.9 0 3
TDr 95/01932 64.4abcde 1 3
TDr 89/02665 71.1abcd 0 3
TDr 98/01946 71.1abcd 0 6
TDr 96/01750 15.6 1 3
TDr 01/00382 6.7 0 9
TDr 00/00365 53.3 1 9
Mean 50.5 0.4 4.4
● Flower and virus infection effects on survival rate of vine propagation.
Flowering Mean of
survival
rate (%)
0 54.6A
1 44.4B
Virus Inf. Mean of
survival
rate (%)
0 82.2A
3 59.2B
9 33.7C
Different letters indicate significant differences at the 1% level.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Important technical points for
vine propagation
1)Healthy plant materials as mother plants of
vine cuttings
2) Type of planting materials
3) Physiological age of mother plants
4) New shoots formation from vine cutting
5) Timing of vine propagation (excising &
culture)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Type of planting materials
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Important technical points for
vine propagation
1)Use healthy plant materials as mother plants
of vine cuttings
2) Type of planting materials
3) Physiological age of mother plants
4) New shoots formation from vine cutting
5) Timing of vine propagation (excising &
culture)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Time course of rooting of vine cuttings and growth of
tubers of mother plants on yams (D. alata cv. TDa
95/00361). Bars in each fig indicate % of vine cuttings
with rooting.
Correlation between rooting of vine cutting and dry weight
of tuber formed on mother plantsR
oo
tin
g (
%)
100
80
60
40
20
0
60 90 120 150
Days after transplanting
(Field)
Dry
we
igh
t o
f tu
be
rs
Pe
r p
lan
t (g
)
300
250
200
150
100
50
0
Roo
tin
g (
%)
50
40
30
20
10
060 90 120 150
Dry
we
igh
t o
f tu
be
rs
Pe
r p
lan
t (g
)
100
80
60
40
20
0
Days after transplanting
(screen house)
H. Kikuno, R. Matsumoto, H. Shiwachi, H. Toyohara and
R. Asiedu. (2007) Comparative effects of explants sources
and age of plant on rooting, shooting and tuber formation of
vine cuttings from yams (Dioscorea spp.). Japanese Journal
of Tropical Agriculture Vol. 51, Extra issue 2, October 13-14.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Matsumoto R., H. Shiwachi, H. Kikuno, K. Irie, H. Toyohara, A. Komamine and H. Fujimaki. Characterization of sprouting and shoot-forming
processes of rooted cuttings of water yam (Dioscorea alata L.). Japanese Journal of Tropical Agriculture, Vol. 54 (3 or 4) (In press)
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
Type C
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
Type C
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-1 K-42
K-45 Arata
a a
aa
a a
aa
b
b
b
b
Type A
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-1 K-42
K-45 Arata
a a
aa
a a
aa
b
b
b
b
Type A
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
rate
(%
)
K-44 Obuko.a
b
b b
b
a
Type B
*
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
rate
(%
)
K-44 Obuko.a
b
b b
b
a
Type B
*
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
Type C
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-31 K-32
Growth stage of mother plant
Type C
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-1 K-42
K-45 Arata
a a
aa
a a
aa
b
b
b
b
Type A
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
ra
te (
%)
K-1 K-42
K-45 Arata
a a
aa
a a
aa
b
b
b
b
Type A
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
rate
(%
)
K-44 Obuko.a
b
b b
b
a
Type B
*
0
10
20
30
40
50
60
70
80
90
100
1st 2nd 3rd 4th
Sh
oot
form
ati
on
rate
(%
)
K-44 Obuko.a
b
b b
b
a
Type B
*
Changes in shoot formation rate of vine
cuttings at different collection times.
Note) Different letters indicate significant
difference at the 5% level by LSD test.
*Obuko. stands for Obukosumbori
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Effect of collecting time of scions and, treatment of gibberellin and
uniconazol-P on the growth of vine cuttings in water yam
56 DAP*
(28 Jul.)
87 DAP
(28 Aug.)
130 DAP
(10 Oct.)
56 DAP
(28 Jul.)
87 DAP
(28 Aug.)
130 DAP
(10 Oct.)
56 DAP
(28 Jul.)
87 DAP
(28 Aug.)
130 DAP
(10 Oct.)
90 a** 100 a 50 ab 100 a 65 b 0 0 35 b 100 a
10 mgl-1 30 c 50 b 50 ab 0 8 c 0 100 a 92 a 100 a
100 mgl-1 50 bc 60 ab 20 b 0 0 0 100 a 100 a 100 a
5 mgl-1 65 b 60 ab 65 a 44 b 83 ab 13 a 56 b 38 b 88 a
25 mgl-1 65 b 90 ab 30 ab 60 b 90 a 8 a 40 b 10 b 92 a
** Different alphabets indicate significant difference at the 5% level by LSD test.
* Day after planting (date of cutting)
UZP
control
Treatment
GA
Table 2 Effect of collecting time of scions and, treatment of gibberellin and uniconazol - P
on the growth of vine cuttings in water yam
Rate of mini tuber formationRate of shoot formationRate of root fomation
Matsumoto R., H. Shiwachi, H. Kikuno, K. Irie and H. Toyohara. Effect of collecting time of scions and treatment of gibberellin and uniconazole-P
on the growth of vine cuttings in water yam (Dioscorea alata L.). Japanese Journal of Tropical Agriculture Vol. 3 (2) or Vol. 4 (1) (2010) (In press).
R. Matsumoto, H. Shiwachi, H. Kikuno, K. Irie and H. Toyohara. (2010) Effect of collecting time of scions and, treatment of gibberellins and
uniconazol-P on the growth of vine cuttings in water yam (Dioscorea alata L.). Japanese Society for Tropical Agriculture, Research for Tropical
Agriculture Vol. 3, Extra issue 2, pp51-52. October 09-10, Okinawa, Japan.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Important technical points for
vine propagation
1)Healthy plant materials as mother plants of
vine cuttings
2) Type of planting materials
3) Physiological age of mother plants
4) New shoots formation from vine cutting
5) Timing of vine propagation (excising &
culture)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Seedlings of vine cutting with new shoots
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
New shoots formation from vine
cutting
Table. Comparison of survival rate (%) of seedlings from vine cuttings of
yam (TDr 95/18544) at 60 days after transplanting at open-field under dry
season with irrigation.
Vine cuttings (VC) with
new shoots
Vine cuttings (VC) without
new shoots
No of planted
vine cuttingsn = 120 n = 640
No of survived
vine cuttingsn = 102 n = 145
% of survived
vine cuttings85.0 ± 5.0 22.7 ± 9.0
Vine cuttings both planting materials (with and without new shoots) were
excised same day (10 October). Seedlings were cultured in screen house
for 1 month, then transplanted at open field by 25cm x 1m spacing. Data of
VC with new shoots and VC without new shoots were collected from 3 and
4 replications respectively.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Important technical points for
vine propagation
1)Healthy plant materials as mother plants of
vine cuttings
2) Type of planting materials
3) Physiological age of mother plants
4) New shoots formation from vine cutting
5) Timing of vine propagation (excising &
culture)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
This results obtained from collaborative research with NARS partner
(NRCRI Umudike, Nigeria, Mazza Mary-Ann and Ikeorgu J. G.) in 2009
Effects of seasons of vine cutting on the development of roots and tubers of yam
D.rotundata (TDr 89/2665) at 21days after vine cutting (DAC) each month.
Date of preparation of
cuttings
Number of
cuttings
% of vine cuttings
with new roots
% of vine cuttings
with new roots &
tubers
2009-05-26 n = 75 47 41
2009-06-25 n = 75 64 48
2009-07-30 n = 75 20 9
2009-08-30 n = 75 11 4
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Yield of tubers through vine
propagation
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
0
20
40
60
80
100
120
140
160
180
200
Frequence
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170
Fresh weight of tuber (g)
Difference size of tubers harvested from plants which were propagated from vine cutting of
white yam (cv. TDr 95/ 18544) without rooting stage before planting into open field. Black and
white bars show frequency of tubers propagated from vine cuttings excised from plants
cultured in screen house which originated from tissue culture materials and from plants
cultured in open field propagated by mini sett of tuber. Plants were cultured from June 2008 to
December 2008 under natural weather condition.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Yield of tubers harvested from plants which were used different size of seed
tubers produced by vine propagation.
Size of seed tubers
and mini-setts
Fresh weight of tubers (g) /
plant
Estimated yield per ha
(Mt)
Less 10g (SHM) 427.6ab 17.2
Less 10g (FM) 325.6b 13.2
10-30g (SHM) 570.0a 22.8
10-30g (FM) 555.8a 22.4
25-30g sett
(Control) 391.6b 15.6
Mean 454.1±105.9 18.2±4.2
Seed tubers were planted by 25cm x 1m spacing on ridges. Seed tubers were
produced by vine propagation. Vine cuttings were directly planted in field
without rooting stage in July and seedlings established were cultured by
December for 6 months under natural rain condition. SHM: Plants (originated
from tissue culture materials) cultured in screen house, FM: Plants cultured
in open field (from mini-sett).
How size of tuber can we harvest from seed tubers
propagated by vine cuttings?
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Harvested tubers from the plants
which seed tubers were propagated
by vine cuttings
From Mini-sett
*This trial has been repeated to use different clones in 2010.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
1) Stabilize shooting and rooting from vine cutting for all
type of plant materials (species and varieties)
2) To reduce technical steps for vine propagation (direct
planting of vine cutting)
3) Find alternative of carbonized rice husk (CRH) for
rooting media or reduce of quantity of CRH
4) Introduce virus detection test into this system
5) Expansion of usage of vine propagation for research
tools (i.e. breeding)
Further direction for innovation to stabilize
vine propagation on yams
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Improve propagation
techniques
Development of meristem culture
protocol for yam germplasm
management
Off-season yam
cropping system
(Seed tuber from
vine propagation)
Healthy seed tuber production
system on yam through vine
propagation
Other research
activities used
seedlings from
vine propagation
as new tool
Capacity building
Network Collaboration
Communication
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
-Control of tuber dormancy-
Breakthrough of off-season (all year round)
yam cropping
Selection early or late sprouted tuber (traditional)
Broken dormancy
Plant growth regulators
(Gibberellic acids: GAs synthesis inhibitors)
Prolong dormancy
GA treatment
Low temperature storage (15℃)
Controlled cultivation through year round
Acclimatized plants from in vitro plantlets
Seedlings from vine propagation
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Dorman-cy
Dorman-cy
Sprout-Planting
Sprout-Planting
Growth of top
Growth of top
Growth of top
Tuber enlargem
ent
Tuber enl.-
Harvest
Tuber enl.-
Harvest
Maturing-Harvest
Maturing-Harvest
Model of natural growth cycle of yam (cultivation) and
controlled growth cycle of yam for off-season cropping
Sprout-Planting
Growth of top
Growth of top
Growth of top
Tuber enlarge
ment
Tuber enl.-
HarvestTuber enl.-
Harvest
Maturing-Harvest
Maturing-Harvest
Dorman-cy
Dorman-cy
Sprout-Planting
Natural growth cycle of yam Controlled growth cycle of yam
Jan
Feb
Apr
JanDec
Nov
Oct
Sep
Aug
Jul
Jun
Feb
May
Mar
Dec
Nov
Jul
Oct
AugJun
May
Apr
Mar
Sep
★Clones from dormancy season shifted tubers will keep same life cycle. Control dormancy of tubers would be
Preferred by research institutes and it’s special seed tubers as like breeding variety disseminate to farmers.
Famers will just plant field in inland valleys, wet land or irrigated land under dry season.
Milking
Milking
i.e. VC
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
• Strong price fluctuation of yam through year
• Yam price higher than other crops
Note: rainfall data is only available from 2005 to 2008.
0
20
40
60
80
100
120
140
160
180
200
2004.01 2004.07 2005.01 2005.07 2006.01 2006.07 2007.01 2007.07 2008.01 2008.07
Pri
ce
(N
air
a/k
g)
Year
Retail prices of major crops in Bida market
Millet
Rice
Sorghum
Cassava
GariYam Tubers
Regina H. Y. Fu, H. Kikuno, M. Maruyama. Research on yam production, marketing and consumption of Nupe farmers of Bida region, Niger
State, central Nigeria. 47th Japan Association for African Studies, May 2010, Nara, Japan.
Yam
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Preliminary surveys to understand basic back ground of agricultural environments,
production of Bida, Niger state, Nigeria---JIRCAS collaborative research
Effects of nitrogen application on growth and yield under “Rice – Yam cropping
system”----JIRCAS collaborative research
1) Enhance income of small householders to access in land valleys, wetland,
and irrigation land
2) Diversify crops to be adopted into wetland, irrigation land and inland
valleys with or without rice based cropping system
3) Supply foods in off crop season (especially beginning of rainy season)
Off-season yam cropping
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Season Rain Rain
Dry
Dry Dry Dry Dry Dry Dry
Rain
Rain Rain Rain Rain
Traditional
culitvation
R R R R C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
R = Rice, C = Cassava, V = Vegetables
Cultivated crops during dry season in inland valley
in Bida, Niger state Nigeria
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug
Season Rain Rain
Dry
Dry Dry Dry Dry Dry Dry
Rain
Rain Rain Rain Rain
Traditional
culitvation
R R R R C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
C
or
V
Off-season
yam cropping
(2009-2010)
R R R R R
Y
C
F
Y
C
F
Y
C
F
Y
C
F
Y
C
F
Y
C
F
Y
C
F
Y
C
F
Off-season
yam cropping
(2010-2011)
R R R R R
Rice-Yam cropping system tested at inland valleys (3 villages)
in Bida, Niger state, Nigeria (support of WIN2000)
R = Rice (WITA4), C = Cassava, V = Vegetables, Y = Yam (TDr 95/18544), and F = Fallow
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Rice-Yam cropping system tested at inland valleys (3 villages)
in Bida, Niger state, Nigeria (support of WIN2000)
Jul
2010
Nov
2009
Jan
2010
Jul
2010
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Cassava Yam
Village SiteFresh weight of
tuber (kg) /plant
Water
content (%)
Fresh weight of tuber
(kg)/plant
Water
content (%)
Lagun
A 1.06 69.8 1.29 70.6
B 1.12 63.5 0.98 66.6
C 1.77 62.4 1.22 69.1
Mean 1.32ac 65.2 1.16 a 68.8
Ejeti
A 0.24 68.4 0.76 65.8
B 0.76 61.8 1.26 67.2
C 0.77 57.8 0.83 71.5
Mean 0.59 b 62.6 0.95ab 68.2
Emitundata
A 1.04 64.3 0.66 70.6
B 1.68 56.4 0.82 71.8
C 0.47 64.8 0.94 70.8
Mean 1.06 c 61.8 0.80 b 71.0
Mean
(Total) 0.99 63.2 0.97 69.3
Yield of yam & cassava in dry season cropping in inland valleys at Bida,
Niger state
Different letters indicate significant differences at the 1% level.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
N treatment (t/ha) No of
tuber/plant
Fresh Weight of
tubers/plant (kg)
Water content in
tuber(%)
Dry Weight of
top/plant (g)
Rice 0 -Yam 0 1.7 1.74 63.4 157.2
Rice 0 -Yam 60 2.0 2.62** 60.9** 224.8**
Rice 30 -Yam 0 1.4 1.43 63.1 136.1
Rice 30 -Yam 60 1.7 2.55** 59.1** 215.0**
Mean 1.7 2.08 61.7 183.3
Effects of nitrogen application on growth and yield of
yam under “Rice – Yam cropping system”
Oct 2009 Jan 2010 July 2010
** indicates significant differences at the 1% level.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
【Further
plan】
As those trials have been carrying out, all some
data will be collected by middle of 2011.
1)Identify the growth and yield of rice
2)Analysis of soil fertilities before rice, after yam
and after rice
3)Analysis of nutrients uptake from rice and yam
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Improve propagation
techniques
Development of meristem culture
protocol for yam germplasm
management
Off-season yam
cropping system
(Seed tuber from
vine propagation)
Healthy seed tuber production
system on yam through vine
propagation
Other research
activities used
seedlings from
vine propagation
as new tool
Capacity building
Network Collaboration
Communication
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Effective chromosome observation protocol for yam are needed.
Obstacle of chromosome observation on yam
● Large number & very small size of chromosome (0.5μm~2.9μm)
● Acicular crystal in cell
● Difficult to collect picture of chromosomes in metaphase in cell which
is appropriate to chromosome observation.
Optimum time for collection of root samples for
chromosome observation on yams
(Dioscorea spp.)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Optimum time for collection of root samples for
chromosome observation
Roots from seedlings
of vine cutting
Roots from mini-sett
(dark condition)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
1 2
4 5
3
Periodicity in the cell division, TDr. 95/18544
(white yam)
1 Interphase
2 Prophase
3 Metaphase
4 Anaphase
5 Telophase
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Chronometrical changes in the frequency of metaphase cells of root tips from minisett.
Different letters indicate significant differences at the 5% level. (Fisher’s LSD test)
【Results】
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
tim e period from sunrise (hours)
mean no. of metaphase cell
b
a
bab
b
TDr. 95/18544
LSD: 3.09
bb
ab
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
tim e period from sunrise (hours)
mean
no. of metaph
ase cell
b
a
bab
b
TDr. 95/18544
LSD: 3.09
bb
ab
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
tim e period from sunrise (hours)
mean no. of metaphase cells
TDa. 98/01183
LSD: 3.56
a
a
a aa
a
aa
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
tim e period from sunrise (hours)
mean no. of metaphase cells
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
tim e period from sunrise (hours)
mean no. of metaphase cells
TDa. 98/01183
LSD: 3.56
a
a
a aa
a
aa
Roots from minisett
White yam Water yam
● The peak in the frequency of metaphase cells is at 7 hr after sunrise (13:00pm)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
tim e period from sunrisemean no. of metaphase cell
b
a
b
ab
TDa. 98/01183
LSD: 3.13
b
bb
ab
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
tim e period from sunrisemean
no. of metaph
ase cell
b
a
b
ab
TDa. 98/01183
LSD: 3.13
b
bb
ab
White yam Water yam
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
timeperiod from sunrise (hours)
me
an n
o. o
f m
eta
ph
ase
ce
ll
aba
bb
ab ab
TDr. 95/18544
LSD: 3.19
b
ab
0
1
2
3
4
5
6
7
8
1 4 7 10 13 16 19 22
time period from sunrise (hours)
me
an n
o. o
f m
eta
ph
ase
ce
ll
aba
bb
ab ab
TDr. 95/18544
LSD: 3.19
b
ab
【Results】
Roots from seedlings of vine cuttings
● The peak in the frequency of metaphase cells is at 4 hr after sunrise (10:00am)
Chronometrical changes in the frequency of metaphase cells of root tips from seedlings
of vine cutting. Different letters indicate significant differences at the 5% level. (Fisher’s
LSD test)
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Identified optimum time for collection of root
samples for chromosome observation through
year round due to usage of minisett (tuber-
under storage period) and seedlings of vine
cutting (growth stage)
【Conclusion】
Babil P.K., H. Kikuno, H. Shiwachi, H. Toyohara, J. Fujigaki,
H. Fujimaki, and R. Asiedu. Optimum time for collection of
root samples for chromosome observation in yams
(Dioscorea spp.). Tropical Agriculture and Development
Vol. 54 (3) (2010): pp.71-75.H.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Improve propagation
techniques
Development of meristem culture
protocol for yam germplasm
management
Off-season yam
cropping system
(Seed tuber from
vine propagation)
Healthy seed tuber production
system on yam through vine
propagation
Other research
activities used
seedlings from
vine propagation
as new tool
Capacity building
Network Collaboration
Communication
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Capacity building (Major research fellows)
1) 2007: Mr. Babil Pachakkil Kalari Thotathil (Msc), Tokyo Univ. Agri. Japan, India
2) 2008: Mr. Kabindra Prasad Kandel (Msc), Tokyo Univ. Agri. Japan, Nepal
3) 2009: Mr. Yuichi Hasegawa (Msc), Tokyo Univ. Agri. Japan
4) 2010: Mr. Jyunya Ohata (Msc), Tokyo Univ. Agri. Japan
1) 2007: Mr. Acha Ivo (Ph. D), Univ. Ibadan, Cameroon
2) 2009: Ms. Delphine Mapiemfu (Ph. D), (as adviser) Cameroon
3) 2010: Mr. Oyelami F. Olayemi (Msc), Univ. Ibadan, Nigeria
4) 2010: Ms. Okunade Adnike Oluwagade (Msc), Univ. Ibadan, Nigeria
Degree related students from African countries (more than 12 months)
Degree related students from Asian countries (6-7 months)
Japan-CGIAR Fellowship Program (2 months)
1) 2009: Mr. Takuya Koyama (Msc), Nagoya Univ., Japan
2) 2009: Ms. Saori Namba (Msc), Kobe Univ., Japan
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
1) 2007: Mr. Shaali Mohamed Shaali, Kizimbani Research Station,
Zanzibar, (Tanzania)
2) 2007: Mr. Gerald Sereje, Root and Tuber Improvement Program, Mutanda
Research Station, Solwezi, Zambia
3) 2008: Mr. Yahaya Asieku, CSIR, Savanna Agric Research Institute (SARI),
Ghana
4) 2009: Mr. Ikoro Ikoro Anyim, NRCRI Umudike, Nigeria
5) 2009: Mr. Ouyabe Michel, CSRS/ESA (INP-HB), Cote d’Lvoire
6) 2010: Ms. Christine Kaari Gitonga, Kenya Agricultural Resaerch Institute,
National Genebank of Kenya, Kenya
Rapid & mass propagation system for yams (Dioscorea spp.)
based on vine cuttings and tissue culture techniques
On-the Job training (3-5 months)
Japan capacity building program for African
Agricultural Researchers funded by MAFF and
implemented by ICCAE, Nagoya Univ.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Communication, Collaboration &
Network
Communication (Media)
2009: NHK-BS special and General, Japan, “Root and tuber
crops save the world” on air at 3 times
2009: NHK-BS, Japan, “World-Agora”
2010: Press tour 2010 hosted by the embassy of Japan
2007-2010: News papers, Magazines
Collaboration & Network
JIRCAS (2009-)
Tokyo University of Agriculture (2006-)
Kinki University (2006-)
Private sectors in Japan
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Further challenges for enhancing
livelihood of farmers in Africa
through improved technologies on
yam
Packaging & distribution of clean seed production
system through improved propagation technologies
Development screening tools for agricultural traits
of yam using mini tubers or seedlings through vine
propagation
Other physiological & agronomic research activities
Expanding and strengthen research networks,
funding and collaboration
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Packaging & distribution of clean seed
production system
through improved propagation
Activity 1:
Identification of robust technologies for propagation (vine
propagation, minisett techniques and in vitro micropropagation)
of high quality breeder’s and foundation seed to be adopted by
NARS in West Africa
Activity 2:
Backstopping study on vine propagation to be used by
commercial seed production farmers or intensive farmers with
potential to adopt mechanization
Activity 3:
Introduce clean & mass yam seed tuber production system
through vine propagation with/without in vitro micropropagation
for 5 NARS partners in West African countries.
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Development diagnostic tools for agricultural traits
of yam using mini tubers or seedlings through vine
propagation
Activity 1:
Develop screening tools for resistance of nematodes using seedling
of vine cuttings
Activity 2:
Rapid & small-footprint method to identify and screen physiological
traits on yam (screening of maturity of plants, response of chemical
fertilizer, day length response, dormancy as well as drought
resistance) using seedlings or mini-tubers produced by vine
propagation
International Institute of Tropical Agriculture – Institut international d’agriculture tropicale – www.iita.org
Thanks
*MOFA, Japan and embassy of Japan
*JIRCAS, Japan
*ICCAE, Nagoya University, Japan
*Tokyo University of Agriculture, Japan
*Kinki University (Hirose Project), Japan