Diallel analysis for yield and yield component traits in toria (Brassica rapa L.)

Combining ability and reciprocal effects were estimated for yield and its components along with protein and oil content from a study of 8 x 8 full diallel set. Genotypes being open-pollinated and self-incompatible were bud pollinated to get the parental seed before inclusion into diallel mating. Significant sca variances exhibited their importance for all the traits except for oil content, while the gca variance were non-significant for, for plant height, siliqua length and oil content and significant for rest of the characters. However, preponderance of non-additive gene action was observed for all the traits as reflected by the ratio of gca and sca variances. Reciprocal variances were greater than both the gca and sca variances for plant height, number of primary branches/plant, siliquae on main shoot, siliquae length and seeds/siliquae indicating importance of maternal effects for the expression of these traits. The maternal effect, reflected in most of the crosses involved good general combiner as female parent. Genotypes PT-30, PT-9701, PT-9600 and PT-9700 were good general combiners for seed yield and yield contributing characters along with high per se performances. The high performing crosses for seed yield involved parents with high x high, high x low, low x low and low x high gca effects.