Heterosis and Combining Ability in Grain Sorghum (Sorghum bicolor) (L.) Moenche

Abstract

Substantial degree of heterosis was observed for all the characters. The maximum heterosis was expressed by the plant height and earhead length. The next in descending order were seed size, days to maturity, panicle width, grain yield and days to 50% bloom. Hybrids involving locals were higher yielding and early in maturity.For grain yield and its associated characters like height, maturity and seed size, additive genetic variance was found in preponderance. Although in certain cross combinations and for yield contributing components, like panicle length and panicle width non-additive genetic variance was also observed in predominance. Thus it indicated the utility of both conventional and heterosis breeding for sorghum improvement work.The local varieties B. P. 53, Sona-108 and Surat-1 have emerged out good general combiners but they could not be used directly since they are tall and late in maturity. Hence these varieties are to be converted into suitable types to be used in hybrid production. Both GCA and SCA effects are of importance for grain yield in sorghum