Wilson, DBhadra, KKAU2019-05-022019-05-021998171414http://krishikosh.egranth.ac.in/handle/1/5810101662PGThe research programme was carried out in diallel manner at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, Thiruvananthapurarn during 1996-98. The objective was to assess the general and specific combining abilities and gene action involved in the inheritance of biological nitrogen fixation traits and yield attributes in green gram. The study was conducted in a diallel model in a replicated field experiment using seven varieties of greengram, out of them four were high yielders and three with good nitrogen fixing capacity. Seven parents and twenty one hybrids were also raised in pots with seven replications to study the nodulation efficiency of hybrids and parents. Analysis of variance revealed highly significant differences among the genotypes for all the characters. Except for nitrogen content at 50% flowering and harvest index, gca effects were not significant, for all the other characters both gca and sea effects were significant. The additive to dominance ratio indicated a preponderance of non-additive gene action for all characters except number of secondary roots and weight of nodules. The combining ability analysis revealed that NDM-88-14 was the good general combiner with respect to important nitrogen fixation traits where as P-9333 was the best general combiner with respect to yield and 2 other yield attributes. P-9333 x NDM-88-14 was the best specific combiner for nitrogen content. P-9333 x IIPRM-3, IIPRM-3 x LGG-444 and P-9333 x COGG-902 were the best specific combiners for yield and yield attributes. Combining the mean performance, sca effects and heterobeltiosis P-9333 x NDM-88-14 was identified as the good hybrid combination for nitrogen fixation traits. Re~arding yield, the hybrids P-9333 x IIPRM-3, P-9333 x COGG-902 turned out to be outstanding. Therefore, these hybrids can be utilized for crop improvement programme.ennullThesis