JIRCAS

21 Oct. , 2013at

3rd Africa Rice Congress

Genetic diversity in rice (Oryza spp.) for resistance to blast disease

in West Africa

T. Odjo, Y. Koide, S. Yanagihara, M. Sié, Y. Séré, D. Silué, T. Kumashiro and Y. Fukuta

①Breakdown of resistance

①Survey of blast races and resistance genes in

rice and their utilization.

Prepare improved germplasm for African environment

Apply for multi-environmental varieties trial by Breeding Task Force.

National institute for breeding or farmers fields in Africa

②Introduction of long root geneqRL6.1.

④Utilization of deep root germplasm

③ Yield barrier in nutrient deficiency(Phosphorous）

④Drought (Upland and rainfed lowland)

Actions

Problems to be solved

Actions

Upland rice Irrigated rice

②Yield barrier in nutrient deficiency （ Nitrogen）

③Introduction of P def. tolerance gene, Pup1.

Ⅰ. Improvement of existing varieties Ⅱ. Introduction of improved lines from Asia

Introgression lines developed under the collaboration between JIRCAS and IRRI.

Selected lines.

Strategies for rice variety improvement to increase/stabilize rice production in Africa under the collaboration between JIRCAS and AfricaRice.

②Introduction of long root gene qRL6.1.

Evaluate under African environment and select the best performers.

①Survey of blast races and resistance genes in

rice and their utilization.

Sharing information

-Rice blast disease caused by Pyricularia oryzae Cavara (syn. Magnaporthe oryzae B. Couch) is a fungal disease of rice known to cause yield losses in most rice producing areas of the world.

-In Africa, it is a major constraint of rice production.

-The most economical and effective way of controlling rice blast in resource-poor farmers’ fields shall be the development of resistant cultivars.

Problem of rice blast disease

Problem of rice blast disease 2

-However, the causal fungus is able to overcome the resistant varieties after they became popular.

-Thus, ideal high performance varieties require lower inputs with more stable resistance to blast disease.

-To achieve this breeding goal, it’s important to assess rice accessions from Africa.

Survey of blast resistance in rice germplasm from West Africa

Species StatusIrrigatedlowland

Rainfedlowland

Upland Manglove Total

O. sativa Improved 9 18 22 6 55

O. glaberrima Landrace 10 4 8 23 45

Interspecific Improved 0 42 18 0 60

O. barthii Wild 0 0 5 0 5

Total 19 64 53 29 165

Plant materials used in the survey

In addition,- 23 monogenic lines targeting for 23 resistance genes　（ Tsunematsu et al., 2000),- 2 NILs for Pik and Pik-h with a Chinese Japonica-type variety Lijiangxintuanheigu

(LTH) genetic background（ Telebanco-Yanoria et al, 2010),- 2 NILs for Pi5(t) and Pi12(t) with a Indica type susceptible line US-2 genetic

background（ unpublished materials),- and Nipponbare, Kasalath, US-2, and LTH as control varieties

Blast races used for survey and their origin

Survey of blast resistance in rice germplasm from West Africa

Survey of blast resistance in rice germplasm from West Africa

Cluster analysis for rice germplasm

I(n=8)

III(n=27)

II(n=53)

IV(n=108)

Rice germplasm in West Africa and control varieties were classified into 4 cluster groups based on the reaction patterns to blast isolates from Japan and West Africa

Ma

56

Ni2

CI9

Ma

37

CI1

4

Ma

29

60

43

32

53 9

Bn

45

Mea

n

I 8 ( 8) 3.7 4.4 3.6 3 3.2 2.8 3.7 2.9 4 3.9 3.2 3.3 3.5II 53(11) 1.3 1.4 1.4 1.6 0.8 1.3 2.7 1.7 2.6 2.2 1.2 1.6 1.7III 27(10) 2.2 2.4 0.9 2.3 0.3 2.2 3.5 2.9 4.6 3.9 0.9 3.5 2.5IV 108( 2) 0.1 0.3 0.4 0.5 0.4 0.3 2.5 0.1 0.4 0.9 0.6 0.2 0.6

Res

ista

nce

gro

up

No

. o

f a

cces

sio

n Mean values of Infection degreed to each blast isolates

Isolates from West Africa

18

04

-4

P-2

b

05

28

-2

Ao

92

-06

-2

Mu

18

3

Ai7

9-1

42

Mu

95

GF

OS

8-H

Ky

u8

9-2

46

Sa

sam

ori

12

1

IW8

1-0

4

Ai7

4-1

34

24

-22

-1-1

TH

68

-14

0

Ina

93

-3

Ky

u9

2-2

2

TH

68

-12

6

Ina

86

-13

7

31

-4-1

51

-11

-1

Ken

53

-33

Mea

n

I 4 1.3 3.7 4.1 3.3 3.9 3.5 4 4.1 3.8 3.8 3.8 4 3.7 4 4.5 3.9 4.3 4.4 4.5 3.8 3.6II 0.9 0.7 1.3 1.7 1.2 1.5 1.1 1.3 1.3 1.1 1.3 1.6 1.3 1.7 0.9 1.4 0.7 1.2 1.3 1.6 1.3 1.6III 1.7 0.6 1.4 3 2.5 2.8 0.6 0.6 0.8 2.8 2.7 2.7 2.6 2.3 0.4 2.9 1.5 1.8 2 2.6 1.9 2.3IV 0 0.1 0.3 0.3 0.4 0.5 0.3 0.3 0.3 0.3 0.3 0.5 0.2 0.4 0.2 0.1 0.1 0.2 0.2 0.2 0.3 0.5

Mean values of Infection degreed to each blast isolates

Res

ista

nce

gro

up

Wh

ole

mea

nIsolates from Japan

( ): No. of differential and control varieties.

Infection scores of rice accessions to standard differential blast isolates from West Africa and Japan

Survey of blast resistance in rice germplasm from West Africa

1

23

4

1

23

4

Groups based on reaction patterns to blast isolates

No. and name of rice accessions and differential varieties

No. of rice accessions

(Differential varieties and

checks)

I 1: LTH, 1: US-2, 5: DVs (Pik-s, Pi19(t), Pia, Pish, Pi12(t)) 1: Nipponbare

8(8)

II

10: DVs (Pi20(t), Pib, Pi12(t), Pit, Piz, Piz-5, Pita x2, Pita-2 x2) 4: JA(UP-I), 2: JA(UP-L), 1: JA(LO-I) 1: Kasalath, 1: IN(DW-L) 1: NO(LO-I) 3: NERICA (UP-IS) 9: AF (DW-L) , 10 AF (LO-L) , 9: AF (UP-L) 2: W (UP)

53(11)

III 10: DVs (Pii, Pi3, Pi5(t) x2, Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t) ) 14: AF (DW-L) , 2: AF (LO-L) 1: W (UP-L)

27(10)

IV

2: DVs (Pi9(t), Piz-t) 6: JA(UP-L) , 1: JA (UP-I), 2: JA (UP-L) 14: IN(LO-I), 3: IN(LO-L) , 4: IN (DW-I), 1 IN(DW-L), 9: NO(LO-I), 1: NO (UP-L) , 5: NO (UP-I) 15 NERICA (UP-IS) , 42 NERICA (LO-IS) 1: AF (LO-L) 2: W (UP)

108(2)

Total

196(31)

Classification of rice accessions in West Africa based one the reaction patterns to standard differential blast isolates from West Africa and Japan

Survey of blast resistance in rice germplasm from West Africa

Conclusion

-Rice accessions from West Africa, DVs and check varieties were classified into 4 groups I, II, III and IV, based on the reaction patterns to the 20 standard differential blast isolates from Japan and the 12 isolates from West Africa.

-106 accessions including 15 rainfed upland NERICAs, all lowland NERICAs, one O. glaberrima, two O. barthii, 46 Asian varieties, and two DVs for Pi9, and Piz-t were categorized in the strongest group.

-The wild rice, O. barthii, showed more variation than in O. glaberrima. However, more number of accessions are to be investigated.

JIRCAS

Thank you for your attention.