摘要：Yield component breeding and modification of the plant architecture offer possibilities to develop more efficient breeding systems for increased grain yield . Heterosis and heterobeltiosis studies were done at Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan following Matzinger approach (1956) among seven wheat genotypes viz., Shahkar-95, Parwaz-94, Iqbal-2000, Uqab-2000, MH-97, 4072 and Punjab-96 for crosses in all possible combinations. Yield and yield related traits like plant height, number of tillers/plant, spike length, spikelets/spike, spike density, grain/spike, 1000-grains weight and grains yield/plant were investigated. Results for analysis of variance indicated significant differences among genotypes for many plant traits under study. Maximum significant heterosis (21.95%) was found in grain yield /plant followed by spike length (14.62%) and grain yield /spike (13.68%). While maximum heterobeltiosis was recorded for grain yield /plant (11.33%), followed by spike length (9.13%). It is concluded that 4072 x Punjab-96 cross showed best performance followed by Parwaz-94 x MH-97, Iqbal-2000 x parwaz-94 than other crosses under study. These crosses cab be utilized in further breeding programme as parents for contributing high yield not only under optimum environment but also under drought conditions as water use efficient crosses. The results of heterosis suggest that hybrid vigor is available for the commercial production of wheat and selection of desirable hybrid among the crosses having heterotic effects in other characters is the best way to improve the grain yield of bread wheat.
