Identification of microsatellite markers linked to drought tolerance in rice (Oryza sativa L.) through bulked line analysis

Identification of donor parents and markers for traits conferring drought tolerance eventually hastens the breeding for drought tolerance in rice. The extent of variation for water stress indicators, physio-morphological and plant production traits were assessed by evaluating 36 rice genotypes under water stress condition. Significant variation was observed for these traits and thirteen drought tolerant and susceptible genotypes were selected and grouped as tolerant and susceptible bulks based on physio-morphological and biochemical characterization. Genomic DNA was isolated from these rice accessions and pooled, respectively into drought tolerant and susceptible bulks. Bulked line analysis was carried to identify microsatellite markers linked to drought tolerance in rice. Out of 200 SSR primers screened RM 1092; RM 129 and RM157B were polymorphic between the bulks and also co-segregated among the individual genotypes constituting the respective bulks. The genomic regions flanked by these markers have been identified to be associated with various drought tolerance traits in rice and can be useful for marker assisted selection for drought resistance improvement in rice. The genotypes identified as drought tolerant can be used us donars in drought improvement breeding programmes. Key words Rice, drought resistance, microsatellite markers, bulk line analysis