Combing ability analysis for nitrogen fixation in blackgram (Vigna mungo L. Hepper)

The present investigation was conducted at Plant Breeding Farm, RCA, Udaipur. Experimental material comprised of ten parents and 45 hybrids (adopting half diallel) raised in RBD with three replications in two environments (first-control; second-seed treated with Rhizobium urd culture). The main objective was to estimate combining ability analysis for nitrogen fixation characters. Interaction of GCA and SCA with environment was significant for nodules fresh weight per plant, nodules dry weight per plant, plant fresh weight, plant dry weight, nitrogen content of plant, carbohydrate content, leghaemoglobin content. The ratio of ²SCA/²GCA was greater than one for all the characters studied, there by indicating the preponderance of non-additive gene effects in the inheritance of all the characters. Estimates of GCA effects indicated that parents RBU 36, RBU 28 and RUD 59 were good general combiner for most of the nitrogen fixing traits. These parents could be further used in breeding programme. The crosses T9 x BGU 54, 99-U-27 x RUD 59 and RBU 28 x RBU 38 were best specific combiner for various nitrogen fixing characters. However, these crosses could be used as a high nitrogen fixing capacity for the varietal development by adopting the pedigree method.