Identification of most prominent parents and cross combinations in indian mustard for seed yield and quality traits

Indian mustard is an important oilseed crop with significant economic and nutritional value. Understanding the genetic mechanisms governing key traits like seed yield is crucial for developing high-yielding varieties. This study aimed to evaluate the general combining ability (GCA) of parental lines and the specific combining ability (SCA) of their cross combinations to improve yield potential. A diallel model (excluding reciprocals) was used, involving 45 hybrids (F1's) produced by crossing 10 diverse genotypes: Aashirwad, Basanti, NDR501-26, Rohini, KMR17-5-21, KMR17-5-22, KMR17-5-23, N8501, PR20, and PR21. These hybrids were developed during the Rabi season of 2018-19 and evaluated in the 2019-2020 Rabi season using a Randomized Complete Block Design (RCBD) with three replications at the Student Instructional Farm of CSAUA&T, Kanpur. The study assessed GCA and SCA effects, focusing on additive and non-additive gene actions in trait inheritance. The results showed that SCA variance exceeded GCA variance across all traits, with a predictability ratio and GCA/SCA ratio of less than one, indicating a dominance of non-additive gene action. While GCA variance was high for most traits except primary branches and 1000-seed weight, SCA effects were more significant for traits like maturity days, siliquae per plant, 1000-seed weight, oil yield, and seed yield. Parents like NDR 501-26 and Rohini demonstrated strong GCA effects, making them suitable for breeding. Specific crosses, such as KMR 17-5-22 × KMR 17-5-21 and NDR 501-26 × Rohini, showed desirable SCA effects, suggesting potential for early-maturing and high-yielding hybrids. These findings highlight the potential of heterosis breeding and the use of non-additive gene action for improving Indian mustard yield, offering insights to meet agricultural demands.