GENETIC VARIABILITY, CORRELATION AND PATH ANALYSIS IN F3 GENERATION OF Brassica napus L.

Abstract

An experiment was carried out with 69 genotypes of Brassica napus L. in the experimental farm, Sher-e-Bangla Agricultural University (SAU), Dhaka during November 2015 to February 2016 for estimation of character association and genetic diversity. Analysis of variance revealed significant differences among the genotypes for days to 50% flowering, days to 80% maturity, plant height, branches per plant, siliqua per plant, seeds per siliqua, thousand seeds weight and seed yield per plant. The phenotypic variance and phenotype coefficient of variation were higher than the corresponding genotypic variance and genotypic coefficient of variation. High heritability with high genetic advance in percent of mean was observed for secondary branches per plant, siliqua per plant, 1000-seed weight and seed yield per plant. The significant positive correlations of seed yield per plant were found with plant height, primary branches per plant, secondary branches per plant, siliqua per plant and 1000-seed weight in both genotypic and phenotypic level. Siliqua length, days to 50% flowering and days to 80% maturity was correlated negatively with seed yield per plant. Partial correlation was significant for 1000seed weight, siliqua per plant, plant height and primary branches per plant. Yield showed a significant linear regression coefficient with 1000-seed weight, siliqua per plant, plant height, and primary branches per plant. Path analysis revealed that plant height, primary branches per plant, siliqua per plant, seeds per siliqua and 1000 seeds weight had the positive direct effect on yield per plant. Sixty nine genotypes were grouped into six different clusters and the highest 26 genotypes included in the cluster III. Eigen values of principal component axes showed that three Eigen values above unity accounted for 58.004%. The present study revealed that the cluster V with high mean values for four traits were desired to be crossed with cluster I which possessed low mean values of three characters for getting high heterosis. Same cross between clusters V and II; V and IV. The highest inter-cluster distance was observed between clusters I and VI and the maximum intra-cluster distance was found in cluster V. The results of the present experiment revealed that identification of superior genotypes were G42, G33, G67, G2, G65, G5, G62, G28, G59, G64 and G69. They might be used as open pollinated varieties and parents in future hybridization program.