[P4] Crop Genetics and Physiology

[P4-15] Pyramiding of Disease Resistance Genes into Popular Rice Varieties of Bangladesh

*Nominated for Presentation Awards

^○Tapas Kumer Hore, Corinne Mira Marfori-Nazarea, Mary Ann Inabangan-Asilo, Ratna Wulandari, BP Mallikarjuna Swamy (RGDV Platfrom, International Rice Research Institute, Philippines)

Rice is the major staple food of Bangladesh, contributing to 65-70% of the daily caloric intake. Its stable production is essential to meet the food and nutritional demands. However, rice production is affected by several biotic constraints such as bacterial blight, blast and tungro. Most of the popular rice varieties released during the last two decades are becoming susceptible to major diseases, so pyramiding disease resistance genes by marker-assisted backcrossing is a fast-track approach to address biotic stresses. We introgressed bacterial blight (Xa5, Xa13 and Xa21) and blast genes (Pi9, Pita2 and Pi35) into BRRI dhan28, BRRI dhan63 and BRRI dhan81 rice varieties. We also introgressed tungro resistance gene tsv1 into BRRI dhan71 rice variety. Materials have been advanced to BC₃ generation and homozygous lines selection is in progress using gene-specific markers. While twenty-three BC₃F₃ tungro resistance homozygous lines phenotypically similar to recipient parent have been selected and field evaluated. The overall results of the work will be presented during the conference.