Improved technologies on yam for enhancing livelihood of farmers in Africa

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


Seed yams required to plant one hectare

Seed tubers

Stagnation of yam production could be mostly attributed to high production

costs.


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


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


Improve propagation

techniques



management

Off-season yam

cropping system

(Seed tuber from

vine propagation)



propagation

Other research

activities used

seedlings from

vine propagation

as new tool

Capacity building


Communication


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


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


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)


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


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


Accession Media

MS LS B5

TDr 95/18544 1.6A 4.7B 0.0

TDa 98/01183 10.8A 8.7A 0.8B


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)


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


(Current media component used at Gene bank)

MS media + NAA 1.07μM+ BAP 0.67μM+ GA3 0.23μM


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.


Improve propagation

techniques



management

Off-season yam

cropping system

(Seed tuber from

vine propagation)



propagation

Other research

activities used

seedlings from

vine propagation

as new tool

Capacity building


Communication


Healthy seed tuber

production system on yam

through vine propagation


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


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.


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)



vine propagation


vine cuttings





culture)


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


Cond.


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.



vine propagation


vine cuttings





culture)


Type of planting materials



vine propagation

1)Use healthy plant materials as mother plants

of vine cuttings





culture)


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.


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


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


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


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


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


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


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


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


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.



vine propagation


vine cuttings





culture)


Seedlings of vine cutting with new shoots


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.



vine propagation


vine cuttings





culture)


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


Yield of tubers through vine

propagation


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.


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？


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.


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


Improve propagation

techniques



management

Off-season yam

cropping system

(Seed tuber from

vine propagation)



propagation

Other research

activities used

seedlings from

vine propagation

as new tool

Capacity building


Communication


-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


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


• 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


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


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


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


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


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.


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.


【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


Improve propagation

techniques



management

Off-season yam

cropping system

(Seed tuber from

vine propagation)



propagation

Other research

activities used

seedlings from

vine propagation

as new tool

Capacity building


Communication


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.)


Optimum time for collection of root samples for

chromosome observation

Roots from seedlings

of vine cutting

Roots from mini-sett

(dark condition)


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


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


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


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



0

1

2

3

4

5

6

7

8

1 4 7 10 13 16 19 22



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)


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)


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.


Improve propagation

techniques



management

Off-season yam

cropping system

(Seed tuber from

vine propagation)



propagation

Other research

activities used

seedlings from

vine propagation

as new tool

Capacity building


Communication


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


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.


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


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


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.


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


Thanks

*MOFA, Japan and embassy of Japan

*JIRCAS, Japan

*ICCAE, Nagoya University, Japan

*Tokyo University of Agriculture, Japan

*Kinki University (Hirose Project), Japan

Technology

Improved technologies on yam for enhancing livelihood of farmers in Africa