COMPARATIVE AND GENETIC STUDY OF THE ADVANCED POPULATIONS OF Brassica rapa L.

Abstract

An experiment was conducted by using seventeen F14 generation of Brassica rapa obtained through advancing generation of different inter-varietal crosses and one check variety in Randomized Complete Block Design with three replications at the experimental field of Sher-e-Bangla Agricultural University (SAU), Dhaka during November 2015 to February 2016 growing season to compare the various populations and to study the variability, heritability, genetic advance, correlation and direct and indirect effect of different characters on seed yield. The characters showed significant variations among the genotypes. Phenotypic variance was higher than the genotypic variance for every character. Minimum difference between phenotypic and genotypic variance was seen in number of primary branches per plant, number of secondary branches per plant, siliqua length, number of seeds per siliquae, days to 50% flowering, days to 80% flowering, days to 80% maturity, thousand seed weight and seed yield per plant. Moderate heritability with low genetic advance and high genetic advance in percentage of mean was found in number of secondary branches per plant while high heritability with moderately high genetic advance in percentage of mean was observed in number of primary branches per plant, number of siliqua per plant and seed yield per plant. Significant positive association with seed yield per plant was observed in number of primary branches per plant, number of secondary branches per plant, number of siliqua per plant and thousand seed weight. On the other hand significant negative correlation was found in number of seeds per siliquae, days to 50% flowering, days to 80% flowering and days to 80% maturity. Path coefficient analysis revealed that all the characters had positive direct effect on seed yield per plant except plant height and days to 80% flowering. From this comparative study two advanced populations G16 and G17 were selected based on their better performances over the check variety and other advanced populations in respect of days to maturity, number of primary branches per plant, number of siliqua per plant, thousand seed weight and seed yield per plant to release as a new variety.