GENETIC DIVERGENCE AND YIELD POTENTIAL OF MUSTARD (BRASSICA JUNCEA L.) GENOTYPES UNDER THE AGRO-CLIMATIC CONDITIONS OF SOUTH PUNJAB, PAKISTAN
Abstract
Mustard (Brassica juncea L.) is an important oilseed crop; however, its productivity is constrained by limited genetic improvement and environmental stresses. The present study was conducted to evaluate the genetic variability, trait associations, and genetic divergence among twenty-five mustard genotypes under the agro-climatic conditions of South Punjab, Pakistan. Field experiment was carried out at the Regional Agriculture Research Institute (RARI), Bahawalpur using a randomized complete block design with three replications. Data were recorded for days to 50% flowering, days to maturity, plant height, leaf area, primary branches per plant, siliqua length, number of siliquae per plant, number of seeds per siliqua, thousand-grain weight, and seed yield. Analysis of variance revealed highly significant differences among genotypes for most traits, indicating substantial genetic variability. Correlation analysis showed that seed yield was strongly and positively associated with the number of seeds per siliquae (r=0.997**), thousand-grain weight (r = 0.961**), number of siliquae per plant (r = 0.955**), and plant height (r = 0.944**), suggesting these traits as reliable indirect selection criteria. Principal component analysis demonstrated that the first two principal components explained 79.35% of the total variation, with yield-related traits contributing most to genetic divergence. Cluster analysis grouped the genotypes into two distinct clusters, where Cluster-2 exhibited superior performance for plant height, siliquae per plant, seeds per siliqua, thousand-grain weight, and seed yield. The study confirmed the existence of considerable genetic diversity among the evaluated germplasm and identified promising genotypes and key yield-contributing traits that can be effectively utilized in future mustard breeding programs aimed at improving productivity and adaptation.
