IRRI’s Collaborative Rice Research Activities in Kenya

Rosemary Murori, ScientistIRRI - ESA

1. Evaluation and selection of new breeding lines

2. On farm demonstrations

3. Sharing of best performing lines with NARES to facilitate their breeding programs

4. Characterization

5. Seed production training

6. Small scale farm machinery fabrication

7. Rice Knowledge Bank

8. Pathology studies

Results

Recommendations

Activities

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Evaluation and selection of new breeding lines and on Farm Demos

ON -40 GSR Lines -33- RBW-Uganda

AYT- 13 MET 2012 for stability and adaptability of target environment.

-IRRI-KARI Kibos joint demonstration

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3. Sharing of best performing lines with NARES

3. Characterization of Local Germplasm

Neighbour-Joining tree of simple matching dissimilarity coefficient using SSR

Dendrogram using all genotypes included in study

Judy Joachim, Msc

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5. Seed production Training

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6. Small scale farm machinery fabrication

Hydro-Tiller testing at Mwea

KARI (Kenya) Rice knowledge Bank

8. Pathology studies

Characterization of Pyricularia oryzae population in irrigated ecosystem in Kenya

By:Benson Ouma Nyongesa, Joseph Bigirimana, Beatrice A.

Were, Rosemary Murori

NIB and Collaborators

• Rice blast caused by P. oryzae is one of the major constraints to rice production in irrigated ecology in Kenya.

• Understanding the diversity of blast population in target areas

• Is essential for rice breeding programs focused on disease resistance.

• Objectives: Characterize diversity of blast population and identify genes effective against blast population in irrigated ecosystem in Kenya.

Rice blast disease in a farmers’ fields at the coastal region

MATERIALS AND METHODS

• Sites: Mwea, West Kano and TARDA-Garsen.

• 51 lines, (NILs & monogenic lines ) and 2 parents (CO39 & LTH genetic and 4 local varieties (BW 96, Basmati 270, I|TA 310).

• Basmati 370 was used as susceptible check

• Design: Row-Column design with 3 reps.

• Scoring stage: 60 DAT using 0-5 scale rating system.

RESULTSMean squares for leaf blast lesion type across experimental sites in 2013.

Source of Variation DF SS MS Pr>F

Row 7 0.1303 0.0186*** <.0001

Column 6 0.1372 0.0.0229*** <.0001

Rep 2 0.0011 0.0005 0.8625

Site 2 1.5277 0.7638*** <.0001

Variety 55 3.4732 0.0631*** <.0001

Site*Variety 110 2.1892 0.0199*** <.0001

Error 307 1.1431 0.0036  

General Mean 0.5289

R-Square 0.8671

CV (%) 11.2831

Root MSE     0.0597  

***: Significant at P≤ 0.01

Reaction patterns of 51 differential rice lines to natural blast population at experimental sites in 2013.

Sites R MR S HS

Mwea 2 15 29 5

West Kano 2 8 36 5

TARDA-Garsen 27 5 15 4

Key: R = resistant (scale: 0-2); MR = moderately resistant (scale = 3); S = susceptible (scale = 4); HS = highly susceptible (scale: 5)

Sites % lines/varieties overcome by blast

Mwea 66

West Kano 80

TARDA-Garsen 36

Lines/varieties attacked by blast population at different sites in 2013.

• Significant interaction between sites and lines, indicating that P. oryzae population and pressure differed in all the three sites was observed

• Pathogen diversity:West ano (80%)>Mwea (66%)> TARDA-Garsen (36%)

• Incidence of predominant lesion type: West Kano (90%)> TARDA-Garsen (82%)> Mwea (34%).

Table 4. Differential lines carrying effective genes at different sites in 2013

Sites Resistant genesModerately Resistance genes

Mwea Pish and Pi9Pik-s [IRBLks-S], Piz, Piz-t, Piz5

West Kano Piz-t and Pik Piz-5, Pish, and Pi9

TARDA-Garsen Pik-s from Shin2], Pik, Piz-t, Pik-h, Pik-p, Pi7(t), Pib

 Piz5, Pish, Pi1, Pi9, Pik-m, Pi20 and Pita-2  

Reaction patterns of differential lines to natural blast population at Mwea in 2013.

Plate 3. Reaction patterns of differential lines to natural blast population at West Kano in 2013.

Reaction patterns of lines to natural blast population at TARDA-Garsen. Line 28 (Pita-2), Line 45 (Pik-p) in 2013.

• High diversity of P.oryzae population was observed across the sites.

• Disease pressure: West Kano> TARDA-Garsen>Mwea.

• Re-evaluation of identified blast R genes in 2014.

• Collection of blast pathogens races particularly from East Africa to be used along side others in the development of rice differential system.

CONCLUSION/RECOMMENDATION

ACKNOWLEDGEMENT

•KARI, •MIAD,•NIB-(Ahero/West Kano & TARDA

Thanks

r.murori@irri.org