Inheritance of Resistance to Spotted Stem Borer in Sorghum Genotypes

The spotted stem borer, Chilo partellus is one of the most destructive insect pests of sorghum in East Africa. A study was carried out to determine the inheritance of resistance to C. partellus and other agronomic traits in sorghum. 10 East African adapted high yielding sorghum parents were crossed to 3 resistant donor parents obtained from India using a NC II mating design. The resulting 30 single crosses with their parents and 6 susceptible checks were evaluated under conditions of artificial infestation at two locations. Data were recorded on stem borer damage, grain yield and agronomic traits. Significant differences (P¿0.05) for all the traits examined were found. Additive genetic effects were predominant in the inheritance of leaf damage, deadhearts, number of exit holes, plant height, number of harvestable tillers, panicle length and panicle diameter while both additive and non-additive types of gene action were important for stem tunnel length, days to 50% flowering, panicle weight, 100 seed mass and grain yield.