VARIABILITY STUDY IN F4 POPULATIONS OBTAINED THROUGH INTERVARIETAL CROSS OF Brassica rapa

Abstract

A research was conducted by using twenty F4 populations generated through intervarietal crosses. along with two check varity of Th'avsica rapti and grown in the experimental lhrnt of Sher-e-FIangla Agricultural tinriversity. Dhaka, during October 2010-March 2011 to study the variation indifferent characters, correlation between pairs of different characters and the direct and indirect eflect of dilicrent characters on seed yield per plant of the F4 material to select the plants with high 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 - It was shown that more seggregation exhibited in 14 material. The values of phenotypic variances were higher than the correspondi ig genotypic variances. Days to 50% t1otering. 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 plienotypic and genotypie variances. The values oIGCV 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 the 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 followed by number of secondary branches per plant. days to 50% flowering, length of siliqua, and plant height. Night most promising plants with short duration and higher yield were selected flom twenty crosses ol'thc F4 populations of/irav.cica rapu