Estimation of yield and grain qualities of marker assisted backcross derived lines of submergence rice against sheath blight disease

Sheath blight caused by Rhizoctonia solani is one of the most devastating diseases of rice (Oryza sativa) and causes enormous yield losses over the world after blast, the disease can cause yield loss upto 50 per cent in advanced stage and adversely affects quality of straw. Breeding for resistant varieties is the only viable option to combat the disease efficiently. In this study, our findings showed a significant increase in number of spikelet’s per panicle (3.45 %), test weight (0.62 %) and grain yield (0.72 %) compared to recurrent parent Swarna sub-1. The range of mean performance of 18 BC2F1 selected improved lines varied for per cent disease severity from 26.75 to 43.58 at 16 days after inoculation. Among the 18 improved lines, only four lines (Swarna sub-1-6, Swarna sub-1-32, Swarna sub-1-13 and Swarna sub-1-29) showed resistance score of 1-3. The remaining fourteen lines showed moderate resistance with a score of 3-5. Hence, the resistance line could be exploited in sheath blight resistance breeding programme and the same line can also be released as a variety against sheath blight of rice after testing over multilocation trails.