Heterosis and inbreeding depression for pod yield and its components in groundnut (Arachis hypogaea L.).

Abstract

Thirty-six crosses generated in a diallel fashion excluding reciprocals using nine genotypes were evaluated to study the extent of heterosis and inbreeding depression for pod yield and yield attributing characters in groundnut. Considerable heterosis over better parent (heterobeltiosis) was observed for the number of mature pods per plant, harvest index and biological yield, while the traits like pod and kernel yield per plant showed low heterobeltiosis, and it was absent or in negative direction for the traits like days to 50% flowering, days to maturity, 100-kernel weight, shelling outturn and sound mature kernels in all the crosses. High inbreeding depression was recorded for days to maturity and 100-kernel weight, while fully matured kernels and biological yield did not show any inbreeding depression. The cross combination, TPG 41 × AK 303 exhibited significant and positive heterobeltiosis (16.4%), highest standard heterosis (123.1%) and maximum mean performance (24.2g) for pod yield per plant. Only one cross (NRCG 115 × AK 303) out of 36, showed significant and high inbreeding depression for pod yield per plant. Negative estimates of heterotic effects observed in some traits may be attributed to inter-allelic interactions. No clear-cut relationship between heterosis and inbreeding depression was observed for pod yield and related traits. Superior segregants from the cross, TPG 41 × AK 303 may be selected for further improvement in the pod yield and its contributing traits.