Heterosis and Combining Ability for Yield and Yield Components of Cotton (Gossypium hirsutum L.)

Abstract

Heterosis and combining ability for yield and yield components were determined in a population derived from half diallel crossing of six cotton genotypes. Heterosis and heterobeltiosis occurred in varying degrees. The highest heterosis for lint yield was 66.4 % and for seedcotton yield was 46.3 %. Five of fifteen crosses showed significant heterobeltiosis for seedcotton yield. Significant heterobeltiosis was predicted for crosses of GL-7 X Cucurova1518 and Del Cerro X Cucurova1518 for seedcotton yield, which resulted in 19.5 and 19.0 %, respectively. The analysis of variance to compare between parents and F1 crosses showed that the mean squares of genotypes and general combining ability (GCA) were significant (P<0.01) for all traits studied. However, the mean square of specific combining ability (SCA) was significant only for lint percentage and seed index. The magnitude of GCA was higher than SCA in all cases, indicating that additive gene action was more important than non-additive in the inheritance of the traits. In this study, Cucurova 1518 and GL-7 were good combiners for yield and yield components. The two best crosses for seedcotton yield were GL-7 X Cucurova1518 and Del Cerro X Cucurova1518. Best parents and best crosses could be used to develop high yield breeding materials.