Enhancing breeding potential in Indian mustard (Brassica juncea L. Czern & Coss): variability and association studies in Three F2 populations

This research was conducted to investigate the genetic variability, heritability and relationships among traits in F2 populations of Indian mustard (Brassica juncea L. Czern & Coss) to identify practical breeding approaches for improving yield. Considerable variation was noted in traits associated with growth, yield and its components, highlighting the genetic diversity in the studied populations. Key characteristics such as the number of primary and secondary branches per plant, siliqua per raceme, racemes per plant and seed yield per plant exhibited high phenotypic and genotypic coefficients of variation (PCV and GCV), suggesting significant genetic variability. Traits with high heritability and genetic advance, including primary and secondary branches per plant, racemes per plant, siliqua per raceme and seed yield per plant, indicate a strong influence of additive genetic variance, making them ideal for direct selection. Through correlation and path analysis, key traits such as primary and secondary branches per plant, siliqua per raceme, number of racemes per plant and 1000-seed weight were identified as crucial for enhancing yield. The F2 population from the cross TM-138-1 × KMR(E) 16-1 demonstrated superior breeding potential, as evidenced by higher mean values, broader absolute and standardized ranges, increased phenotypic coefficient of variation and a higher frequency of transgressive segregants compared to other crosses. These results offer valuable insights for breeders seeking to improve productivity and adaptability in oilseed crops.