Genetic Variability Studies among Yield and Its Contributing Traits in Mustard (Brassica napus L.)

Mustard (Brassica napus) belongs to the Brassiacaceae family and is the major edible oil producing crop of Bangladesh. The country spent a huge amount of foreign currency to import edible oil, which could be minimized through enhancing and improving the existing germplasms. To do this, the genetic variability and diversity of the existing germplasm should be evaluated. Thirty-five genotypes of mustard were evaluated based on randomized complete block design with three replications. The genotypes were found significantly variable for most of the characters. Comparatively phenotypic variances were higher than the genotypic variances for most of the characters studied. The high GCV value was observed for number of seed yield per plant. Seed yield per plant exhibited the highest value of heritability followed by number of siliquae per plant while plant height exhibited the lowest value of heritability. The significant positive correlation with seed yield per plant were found in number of primary branches, siliquae length, number of seed per plant, number of seed per siliquae and thousand seed weight. Path co-efficient analysis revealed that days to maturity, plant height, number of primary branch, siliquae length, number of siliqua per plant, number of seed per siliqua, and thousand seed weight, had direct positive effect on yield per plant. Whereas, days to 50% flowering, length of main raceme and number of secondary branch, had direct negative effect on yield per plant. The genotypes were classified in four clusters. The genotypes of cluster IV showed better mean performance while cluster III showed lower mean performance for important component traits including yield per plant. Considering distance and agronomic performance genotypes G23, G5, G22 and G24 might be recommended for future hybridization program.