Combining ability in bhindi

Abstract

The study was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1994 – 95 to estimate the combining ability of six genetically divergent parental strains of bhindi and their 30 F1 hybrids obtained by crossing the six parents in a diallel pattern. The magnitude of heterosis and nature of gene action governing the yield of fruits and other important yield attributes was also elicited through Hayman’s numerical and graphical approach. The combining ability analysis by the Method 1 of griffing’s (1956) approach revealed that the parent P 4 (NBPGR/TCR 864) was the best general combiner for yield and a few yield related characters. Among the hybrids, P1 x P4 (NBPGR / TCR 893 x NBPGR/TCR 864) exhibited outstanding s.c.a. effects for yield. Non additive gene action was found to govern days to first flowering number of flowers per plant, length of fruit, girth of fruit, weight of single fruit, weight of fruits per plant and number of seeds per fruit while the remaining characters were governed by additive gene action. The numerical and graphical analysis indicated overdominance for almost all characters except leaf axil bearing the first flower and incidence of shoot and fruit borer for which complete dominance was seen and leaf number for which partial dominance was noticed. The Vr-Wr graph also indicated the presence of epistasis for weight of fruits per plant, number of seeds per fruit, fruiting phase and height of plant. There was manifestation of heterosis for all the characters studied. The hybrid P2 x P1 (NBPGR/TCR 861 x NBPGR/RCR 893) was the most outstanding for yield and yield related characters when compared to the mid parent, better parent and the standard check and it also exhibited heterosis for tolerance to shoot and fruit borer. The cross P1 x P4 (NBPGR/TCR 893 x NBPGR/TCR 864) was also heterotic for earliness in flowering. In general, the parents NBPGR/TCR 893 and NBPGR/TCR 861 either alone or together produced heterotic combinations.