COMBINING ABILITY OF PLANT HEIGHT, SEED YIELD AND QUALITY TRAITS IN RAPESEED

General and specific combining ability (GCA and SCA) effects of plant height, seed yield, oil and protein contents and also oil and protein yields were estimated for three testers and six lines of spring type of rapeseed using line x tester mating design. Analysis of variance for parents and crosses for all the traits indicated significant genetic variation among the parents and their F-1 offspring. Parents vs crosses mean squares, indicating average heterosis effects, were significant for all the traits except oil and protein contents. High narrow-sense heritability estimates were found for all the traits, except protein yield, indicating the prime importance of additive genetic effects. Correlation analysis based on GCA effects and means value indicating that oil percentage and seed yield had important effects on oil yield. OptxR01, RG06xR01, RG06xR08 and RG3 xR08 with 3241.91, 3213.68, 3334.28 and 3237.45 kg ha(-1) of seed yield were merit cross combinations for improving this trait and all of these combinations had also positive SCA effect for this trait.