3rd Africa Rice Congress Theme 1: Climate resilient rice Mini symposium: Towards improved resistance to biotic stress Presenter: Yanagahira et al.

1. 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
21 Oct. , 2013
at
rd Africa Rice Congress
3
JIRCAS

2. Strategies for rice variety improvement to increase/stabilize rice production
in Africa under the collaboration between JIRCAS and AfricaRice.
Ⅱ. Introduction of improved lines
from Asia
Ⅰ. Improvement of existing varieties
Problems to be solved
Upland rice
Irrigated rice
①Breakdown of resistance
Actions
①Survey of blast races
and resistance genes in
rice and their utilization.
Actions
①Survey of blast races
and resistance genes in
rice and their utilization.
②Introduction of long
root geneqRL6.1.
②Yield barrier in nutrient
deficiency （Nitrogen）
③Introduction of P def.
tolerance gene, Pup1.
②Introduction of long
root gene qRL6.1.
③ Yield barrier in nutrient
deficiency(Phosphorous）
Introgression lines developed under the
collaboration between JIRCAS and IRRI.
④Utilization of deep root
germplasm
④Drought (Upland and
rainfed lowland)
Prepare improved germplasm for African environment
Evaluate under African environment
and select the best performers.
Selected lines.
Sharing information
Apply for multi-environmental varieties trial by Breeding Task Force.
National institute for breeding or farmers fields in Africa

3. Problem of rice blast disease
-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.

4. 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.

5. Survey of blast resistance in rice germplasm from West Africa
Plant materials used in the survey
Irrigated Rainfed
lowland lowland
Species
Status
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
19
64
53
29
165
Total
Upland Manglove
Total
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

6. Survey of blast resistance in rice germplasm from West Africa
Blast races used for survey and their origin

7. Survey of blast resistance in rice germplasm from West Africa
Cluster analysis for rice germplasm
I
(n=8)
II
(n=53)
III
(n=27)
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

8. Survey of blast resistance in rice germplasm from West Africa
Bn45
Mean
3.3
1.6
3.5
0.2
3.5
1.7
2.5
0.6
( ): No. of differential and control varieties.
1
3.9
0.7
1.5
0.1
4.3 4.4 4.5 3.8 3.6
1.2 1.3 1.6 1.3 1.6
1.8
2 2.6 1.9 2.3
0.2 0.2 0.2 0.3 0.5
Mean
Ina86-137
4.5
1.4
2.9
0.1
Ken53-33
TH68-126
3.8
4 3.7
4
1.6 1.3 1.7 0.9
2.7 2.6 2.3 0.4
0.5 0.2 0.4 0.2
Ina93-3
3.8
1.3
2.7
0.3
3
2
Kyu92-22
TH68-140
Ai74-134
24-22-1-1
IW81-04
Sasamori121
Kyu89-246
GFOS8-H
Mu95
Ai79-142
Mu183
Ao92-06-2
0528-2
P-2b
I
4 1.3 3.7 4.1 3.3 3.9 3.5
4 4.1 3.8
II 0.9 0.7 1.3 1.7 1.2 1.5 1.1 1.3 1.3 1.1
III 1.7 0.6 1.4 3 2.5 2.8 0.6 0.6 0.8 2.8
IV 0 0.1 0.3 0.3 0.4 0.5 0.3 0.3 0.3 0.3
4
Whole mean
9
2.9 4 3.9 3.2
1.7 2.6 2.2 1.2
2.9 4.6 3.9 0.9
0.1 0.4 0.9 0.6
31-4-151-11-1
43
3.7
2.7
3.5
2.5
53
60
3.6 3 3.2 2.8
1.4 1.6 0.8 1.3
0.9 2.3 0.3 2.2
0.4 0.5 0.4 0.3
32
Ma29
4.4
1.4
2.4
0.3
CI14
CI9
Ma37
Ma56
3.7
1.3
2.2
0.1
Mean values of Infection degreed to each blast isolates
Isolates from Japan
1804-4
Resistance group
I
8 ( 8)
II 53(11)
III 27(10)
IV 108( 2)
Ni2
Mean values of Infection degreed to each blast isolates
Isolates from West Africa
No. of accession
Resistance group
Infection scores of rice accessions to standard differential blast isolates
from West Africa and Japan
4
2
3
1

9. Survey of blast resistance in rice germplasm from West Africa
Classification of rice accessions in West Africa based one the reaction patterns to
standard differential blast isolates from West Africa and Japan
Groups based on reaction
patterns to blast isolates
I
II
III
IV
Total
No. and name of rice accessions and differential varieties
1: LTH, 1: US-2,
5: DVs (Pik-s, Pi19(t), Pia, Pish, Pi12(t))
1: Nipponbare
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)
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)
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)
No. of rice
accessions
(Differential
varieties and
checks)
8(8)
53(11)
27(10)
108(2)
196(31)

10. 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.

11. JIRCAS
Thank you for your attention.