Heterosis studies for yield and yield-contributing traits in bread wheat (Triticum aestivum L. em. Thell)

Ten bread wheat genotype and their all-possible cross combinations excluding their reciprocals (10 parents+45 F1s) were evaluated in a randomized block design with three replications during Rabi 2022-2023 at Student’s Instructional Farm, C. S. Azad University of Agriculture and Technology-208002, Kanpur, U.P to get the extent of variability and related parameters to select effectively for grain yield and quality character. It is the big challenge for researchers to get high grain yield with high protein. The data was recorded on fourteen characters viz., days to heading (50%), days to maturity, plant height (cm), chlorophyll content, number of productive tillers per plant, spike length (cm), number of spikelets per spike, number of grains per spike, weight of grain per spike (g), 1000 grain weight (g), biological yield (g), harvest index (%), protein content (%) and grain yield per plant (g). Observations were recorded on five randomly selected plants per replication for traits including phenology, morphology, yield components, and quality parameters. Analysis of variance revealed highly significant differences among parents, hybrids, and parent vs. hybrid comparisons, indicating substantial genetic variability and scope for heterotic improvement. Mid-parent heterosis estimates revealed desirable and significant negative heterosis for earliness traits days to 50% heading (up to-11.61%) and days to maturity (up to-11.08%) and plant height (up to-10.62%), which are advantageous for early-maturing and short-statured wheat. Positive and significant heterosis was recorded for yield-contributing traits, with the highest values for number of productive tillers (70.00%), spike length (31.60%), number of spikelets per spike (31.63%), number of grains per spike (29.27%), grain weight per spike (37.63%), 1000-grain weight (14.37%), biological yield (37.10%), harvest index (30.54%), protein content (19.57%), and grain yield per plant (61.79%). The cross DBW 14 × K 9423 consistently exhibited superior performance for multiple yield traits, suggesting its potential for developing high-yielding wheat cultivars. The results emphasize the utility of heterosis breeding for simultaneous improvement in earliness, yield, and quality traits in wheat.