Combining Ability and Heterosis in Rapeseed

The study was initiated to evaluate six female parents (CMS lines) and 3 male parents (testers) in a line × tester mating design at the research field of Sher-e-Bangla Agricultural University, Dhaka, during November 2009 to March 2010 to estimate their combining ability and heterosis.BARI Sharisha-7 was taken as check. The data recorded on 18 F1s and their parents for their combining ability indicated that GCA effect was significant for days to fifty percent flowering, plant height, No. of siliqua per plant, seed per siliqua, primary branches &secondary branches per plant and seed yield per plant . The specific combining ability (SCA) effect was significant for all the characters. High ratio of SCA and GCA variance was observed, indicating preponderance of non additive gene effects in the inheritance of the yield and yield relating characters under study. Among the lines, CMS2, CMS3 and CMS5 were found good general combiners. But seven hybrids were found good specific combiner among eighteen hybrids. The average heterosis for seed yield of eighteen hybrids over mid parent was 19.26% and that of better parent and standard check was7.96% and 73.90% respectively.