Analysis of Combining Ability Variance and Their Effects for Yield and Its Contributory Traits in Progenitors and Offsprings of Greengram (Vigna radiata L. Wilczek)

The current investigation was conducted at the Student Instruction Farm of Chandra Shekhar Azad University of Agriculture and Technology Kanpur, encompassing a genetically diverse nineteen greengram genotypes (comprising 16 lines and 3 testers). These genotypes were crossed in a line x tester fashion during the kharif season of 2021, resulting in the production of 48 F1 hybrids. Analysis of variance revealed that the mean sum of squares attributed to genotypes or treatments was highly significant for all traits in F1 generation, except for the number of branches per plant, indicating limited variability among genotypes for this particular trait. The analysis of variance for combining ability unveiled highly significant disparities for all traits, excluding the number of branches per plant. There was a pronounced variance due to general combining ability (GCA) for traits such as days to 50% flowering, days to maturity, plant height, number of branches per plant, number of clusters per plant, number of pods per plant, and number of seeds per pod, suggesting the predominance of additive gene action for these characteristics. Conversely, for traits such as pod length, 100-seed weight, biological yield, harvest index, protein content, and seed yield per plant, the variance due to specific combining ability (SCA) was more substantial in magnitude. The level of dominance exhibited over dominance for traits including the number of branches per plant, number of clusters per plant, number of pods per plant, pod length, 100-seed weight, biological yield, harvest index, protein content, and seed yield per plant. Partial dominance was observed for traits like days to 50% flowering, days to maturity, plant height, and number of seeds per pod. Specific parental lines, namely SML664, HUM12, KM2426, KM2427, and KM2404, displayed desirable GCA effects and superior individual performances for seed yield per plant. These lines hold promise for utilization as parental components in breeding programs aimed at enhancing seed yield. Furthermore, cross combinations such as KM2403 X KM2241, KM2408 X KM2241, KM2399 X K851, KM2404 X K851, and SML681 X KM2241 exhibited favourable SCA effects for seed yield per plant along with superior individual performances. These combinations can be further exploited in selection schemes to obtain desirable transgressive segregants in subsequent generations.