VARIABILITY STUDY IN F2 PROGENIES OF THE INTER-VARIETAL CROSSES OF Brassica rapa

Abstract

This research work was carried out by using the F 2 population of some inter-varietal crosses of the species Brassica rapa in the experimental farm. Sher-e-I3angla Agricultural University (SAt)). Dhaka during November 2005-March 2006 for estimating the magnitude of variations in characters, heritability, genetic advance, character associations, direct and indirect effect of different characters on seed yield. There were significant variations among the different genotypes used in the experiment. Genetic parameters, number of primary branches/plant. number of secondary branches/plant, length of siliqua. number of seeds/siliqua. days to 50% flowering. 1000 seed weight and yield/plant showed least difference between genotypic and phenorypic variance. Plant height, length of siliqua, number of seeds/siliqua and days to 50% flowering showed low genotypic and phenotypic coefficient of variation. Number of primary branches/plant and secondary branches/plant showed high heritability coupled with high genetic advance and very high genetic advance in percentage of mean. Ilowever. the yield/plant. days to maturity and length of siliqua showed low heritability. Correlation co-efficient analysis revealed that yield/plant had non significant positive association with plant height, number of secondary branches/plant, days to 50% flowering, length of siliqua. number of siliquae!plant and number of seeds/siliqua. Path coefficient analysis revealed that number of seedsisiliqua showed highest direct effect on yieldJplant followed by plant height, number of secondary branches/plant and number of siliquac/plant. Based on the variability study. some F 2 plants showing high heritability for yield contributing characters were selected from some of the cross combinations of the intenarietal crosses of Brassica rapa.