Combining Ability of Yield Attributed Traits in Rapeseed under Adequate and Low Nitrogen Levels = قدرات الجمع المنسوبة للإنتاج في نبات اللفت تحت مستويات ملائمة و منخفضة للنيتروجين

Abstract

Six rapeseed parents and their 15 F2 diallel progenies were studied under stress (N0: no application of nitrogen) and no stress (N1: application of nitrogen) conditions. Significant mean squares of specific combining abilities (SCA) for all the traits, implied the important role of non additive genetic effects for the traits. Nitrogen levels × GCA (general combining ability) mean square was not significant for all the traits which indicating the stability of additive genetic effects in nitrogen application conditions. Nitrogen levels × SCA mean squares were significant for oil content and oil yield, revealed that significant variation of SCA effects of these traits under two nitrogen application conditions. The traits including plant height, 1000-seed weight and seed yield had high narrow-sense heritability estimates at the N0 but 1000-seed weight had high narrow-sense heritability estimates at the N0 and N1conditions. Most of the crosses exhibited significant SCA effects for seed yield at the N0.