VARIABILITY ANALYSIS AND SELECTION FROM F2 MATERIALS GENERATED THROUGH INTERVARIETAL CROSSES OF Brassica juncea

Abstract

A research was conducted by using twenty one F2 populations generated through inter-varietal crosses, along with seven parental genotypes of Brassicajwzcea and w'own in the experimental farm of Sher-c-Bangla Agricultural University. Dhaka, during November 2008-March 2009 to study the variation in different characters, correlation between pairs of different characters and the direct and indirect effect of different characters on seed yield per plant of the F2 materials to select the plants with higher potential. From the values of mean, range and CV (%) of seed yield and yield contributing characters it was confirmed that there were considerable variation present among all the genotypes used in the experiment. The values of phcnotypic variances were higher than the corresponding genotypic variances. Days to 50% flowering, days to maturity, number of primary branches per plant, number of secondary branches per plant, length of siliqua, number of seeds per siliqua. thousand seed weight and yield per plant showed least difference between phenotypic and genotypic variances. The values of CCV and PCV indicated that there was least variation present among most of the characters. The days to maturity, length of siliqua. seeds per siliqua, thousand seed weight showed high heritability with low genetic advance and genetic advance in percentage of mean. Yield per plant had significant and highest positive correlation with length of siliqua, seeds per siliqua and thousand seed weight. The path co-efficient analysis revealed that siliquae per plant had the highest positive direct effect lullowed by number of secondary branches per plant, days to 50% flowering. of siliqua, and plant height. Thirty five most promising plants with short and higher yield were selected from twenty one crosses of the F2 of Brassicajuncea.