The twenty-eight CGMS based pigeonpea [Cajanus cajan (L.) Millsp.] hybrids were examined in the experiment, which involved mating four CMS lines with seven restorer lines in a line by tester mating design evaluated to study heterosis and the combining abilities of hybrids and parents, along with two checks; GT 104 and GTH 1. The mean sum of squares resulting from genotypes was significant for all traits, in accordance with the analysis of variance. It indicates that the parents utilized in hybridization have an appropriate amount of variation. Five cross combinations, viz., GNP 3A × GNPR-20-18, GNP 3A × GNPR-20-10, GNP 4A × GNPR-21-23, GNP 1A × GNPR-20-18, and GNP 4A × GNPR-21-29, manifested significant and positive heterobeltiosis as well as significant standard heterosis over checks GT 104 and GTH 1. The presence of both additive and non-additive gene effects was found by means of combining ability analysis. With the exception of days to 50% flowering, days to maturity, and primary branches per plant, which showed a preponderance of non-additive genetic variation for the inheritance of these traits, the ratio of σ2gca/σ2sca demonstrated that all the characters under consideration showed less than unity. Among parents, GNP 3A and GNPR-20-18 were trustworthy general combiners for yield and other yield related traits among lines. The crosses GNP 4A × GNPR-21-23 and GNP 4A × GNPR-21-29 were found promising hybrids having significant sca effects for seed yield per plant. From the overall study, the crosses GNP 3A × GNPR-20-18, GNP 3A × GNPR-20-10, and GNP 4A × GNPR-21-23 showed higher per se performance along with significant and positive heterobeltiosis, standard heterosis, and a high sca effect for seed yield per plant, which suggested that these hybrids may be used for commercial cultivation. Hybrids with greater sca estimations were the consequence of average × average, good × average, good × good, and average × good general combiners.

Pigeonpea, Cytoplasmic male sterile hybrids, heterosis and combining ability

In order to potentially increase production through the creation of hybrid cultivars in pigeonpea, heterosis breeding has been employed extensively. The estimates of heterosis for seed yield per plant showed that the five hybrids viz., GNP 3A × GNPR-20-18, GNP 3A × GNPR-20-10, GNP 4A × GNPR-21-23, GNP 1A × GNPR-20-18 and GNP 4A × GNPR-21-29 based on superior parent, standard heterosis, and per se performance, were deemed to be the most promising. Both additive and non-additive gene effects, with non-additive gene effects predominant, had an impact on the inheritance of seed yield and its constituent parts. On the basis of general combining ability the most promising parents identified was GNP 3A, among CMS lines and GNPR-20-18 among R lines.

Denish Savaliya, Chirag Chandramaniya, Mukeshkumar Parmar, Manoj C. Suthar, Nileshkumar Tamboli, Hardik H. Patel and D. A. Chauhan (2023). Heterosis and combining ability study in hybrids developed from A2 cytoplasm of Cajanus scarabaeoides in pigeonpea [Cajanus cajan (L.) Millspaugh]. Biological Forum – An International Journal, 15(12): 69-74.