Nature and genetics of response to pigeonpea sterility mosaic virus disease infection in recombinant inbred lines

Sterility mosaic disease (SMD) of pigeonpea caused by pigeonpea sterility mosaic virus (PPSMV) and transmitted by eriophyid mite, Aceria cajani is one of the most important diseases which can cause yield loss up to 95% under favourable conditions. Development and deployment of SMD resistant cultivars is the most eco-friendly and economical method for mitigating losses due to SMD. In the present study, 120 recombinant inbred lines (RILs) derived from SMD resistant (ICP 7035) and susceptible parents (TTB 7) were screened for response to SMD following leaf stapling technique for use in locating genomic regions controlling SMD resistance. Positively skewed and leptokurtic distribution of RILs suggested that the responses to SMD infection were controlled by fewer genes with decreasing and unequal additive effects with complementary epistasis in desired direction. The implications of the results are discussed in relation to the effectiveness of selection for SMD resistance.