Marker-assisted Selection for Incorporating Bacterial Blight Resistance Genes in the Segregating Generationof Rice Variety CO 43

Apopular rice variety of South India, CO 43 is tolerant to high salinity and alkalinity stress but is susceptible to bacterial blight. In the present study, gene-based molecular markers were used for the foreground selection of bacterial blight disease resistance genes Xa21 and xa13 in an inter cross F generation of CO 43. B95-1 X Tetep and B95-1 X Abhaya were used as the donors for Xa21 and xa13 genes. Two hundred and ten plants of the inter cross F₃ generation were genotyped for the two genes. Eleven plants having both the genes in homozygous condition were selected and advanced to F₃ generation for disease screening and agronomic evaluation. All the selected lines recorded a high level of resistance against bacterial blight. Agro-morphological evaluation of the inter cross F₄ lines led to the identification of two lines 59–44 and 59–62 which were superior to CO 43 with respect to both agronomic performance and disease resistance. The selected inter cross F₄ lines will be screened for disease resistance under field conditions and subsequently advanced for yield trials.