Studies on Heterosis, Residual Heterosis and Inbreeding Depression for Yield and Related Traits in Sorghum (Sorghum bicolor L.)

Background: Selection of genotypically superior parents is most challenging task for the development of potential hybrids. In conventional plant breeding, magnitude of heterosis and inbreeding depression has been proved very effective in identifying vigorous parental combinations. Methods: The present investigation was carried out to study the heterosis, residual heterosis and inbreeding depression of forty sorghum crosses (F1s and F2s) obtained by crossing of eight restorer lines with five cytoplasmic male sterile lines in Line x Tester mating design in 2013 and 2014. Observations were recorded on morphological traits viz. days to 50% flowering, days to maturity, plant height, flag leaf length, flag leaf width, panicle length, panicle width, panicle weight,1000 seed weight and grain yield per plant. Result: Among all crosses, ICSA467 x UPC2 and MR750A2 x UPC2 were found to be best for most of the characters. Inbreeding depression was recorded as significantly positive for plant height for most of the crosses indicates the occurrence of transgressive segregants in F2 generation.