Combining ability and heterosis in bittergourd (Momordica charantia L.)

Abstract

The present investigation "Combining ability and heterosis in bittergourd (Momordica charantia L.)" was conducted in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, involving seven parents, 21 hybrids without reciprocals and the check variety Preethi with a view to assess the general and specific combining abilities, the nature of gene action and to estimate the extent of heterosis for 13 characters in bittergourd. Significant differences were noticed among the 29 genotypes for all the characters studied with respect to the mean performance. Among the parents MC 17 (P,) and MC 40 (P6) and among the hybrids MC 18 x MC 40 (P2 ~ P6) had the high mean performance for yield and most of the yield attributes. The estimates of PCV and GCV for most of the traits were comparatively high with very high estimates of heritability and genetic advance indicating the scope of improvement through selection. The combining ability analys.is revealed that both GCA and SCA variances were significant for all the characters indicating the involvement of both additive and non-additive gene action. However, the ratio of additive to dominance variance was less than unity for most of the characters indicating the predominance of non-additive gene action and thereby suggesting the importance of heterosis breeding programme in crop improvement. The parent MC 40 (P6) and the hybrid MC 18 x MC 40 (P2 x P6) were the best general and specific combiners respectively for yield and most of the yield related components.

Several )1ybrids possessed significant relative heterosis, heterobeltiosis and standard heterosis for all the characters except significant standard heterosis for 100 seed weight. The hybrid MC 18 x MC 40 (P2 x P6) recorded the maximum positive standard heterosis for yield and most of the yield attributes. However, the hybrids MC 17 x MC 40 (PI x P6), MC 17 x MC 53 (PI x P7) and MC 18 x MC 53 (P2 x P7) also exhibited good performance with regard to yield and related characters.