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

Abstract

This research work was carried out by using the F2 population of some inter-varietal crosses of th species Brassica rapa in the experimental farm, ~ her-e-Bangla Agricultural niversity ( AU), Dhaka during No ember 2005-Marc.h 2006 for estimating the magnitude of ariations 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 parameter , 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 phenotypic variance. Plant height .. length of siliqua, number of seeds/siliqua and days to 50% flowering showed low genotypic and phenotypic coefficient of variation, umber 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. However .. the yield/plant, days to maturity and length of siliqua showed low heritability, orrelation co-efficient anaJysi revealed that yield/plant had non significant positive association with plant height .. numb r of secondary branches/plant days to 50o/o flowering, length of siliqua .. number of siliquae/plant and number of seeds/siliqua. Path coefficient analysis revealed that number of s eds/siliqua showe highest direct effect on yield/plant followed by plant height number of secondary branches/plant and number of siliquae/plant. Based on the variability study, some F2 plants showing high 11 ritabiliry for yield contributing characters were selected from some of the cross combinations of· the intervarietal crosses of Brassica rapa.