GENETIC VARIABILITY AND CHARACTER ASSOCIATION OF ADVANCED LINES IN Brassica rapa L.

Abstract

An experiment was carried out with 24 genotypes including 4 check varieties of the species Brassica rapa L. in the experimental farm, Sher-e-Bangla Agricultural University (SAU), Dhaka during November, 2013-March, 2014 for estimating the magnitude of variations in characters, heritability, genetic advance, character associations, direct and indirect effect of different characters on seed yield per plant. The phenotypic variances were higher than the genotypic variances. Significant variation was observed among all the genotypes for all the characters studied. Days to 50% flowering, days to 80% maturity showed moderate difference between the phenotypic and genotypic variance whereas minimum differences were found in number of primary branches per plant, number of secondary branches/plant, number of seeds per siliqua, siliqua length and thousand seed weight and yield per plant. Number of secondary branches per plant showed high heritability coupled with high genetic advance in percentage of mean. On the other hand days to 50% flowering, no. of siliqua per plant, yield per plant showed high heritability with moderate genetic advance in percentage of mean. Days to 80% maturity, no. of primary branches per plant, no. of seed per siliqua showed high heritability coupled with low genetic advance in percentage of mean. The significant positive correlation with seed yield per plant were found in thousand seed weight, no. of siliqua per plant, no. of primary branches per plant. Path coefficient analysis revealed that plant height, no. of primary branches per plant, no. of siliqua per plant, siliqua length, thousand seed weight showed positive direct effect with yield per plant. Days to 50% flowering, days to 80% maturity, no. of secondary branches per plant, no of seed per siliqua showed negative direct effect on yield per plant. Beside these days to 50% flowering, days to 80% maturity, no. of secondary branches per plant, no of seed per siliqua showed negative direct effect on yield per plant. Considering all the characters related to yield and early maturity the two advanced lines G3 and G17 have the potentiality toward the development of improved variety that might be a trademark in Brassica rapa L. It may be concluded that a scope relies for further work with G1 (SAUSR-03) that was the earliest matured line with moderate yield.