Combining ability and gene action studies in F1 generation for yield and yield components in wheat (Triticum aestivum L.)

Wheat is a staple food of about 35% of the world population and provides more calories and protein in the world's diet than any other crop. Wheat is the leading food grain of Pakistan occupying the largest area under single crop. It contributes 2.1 % to GDP and 10% to value added in agriculture. Pakistan population derives 40% to 45% of nutrition from wheat. Efforts are being made to improve wheat yield to ensure food security. In this study 5 x 5 diallel analysis was performed involving five wheat genotypes (9718, 9719, 9873, 9874 and Millat 2011) to estimate the combining ability and gene action for yield and yield components. During 2014-2015 these genotypes were crossed in all possible combinations and in 2015-2016 twenty F1s along with their parent were grown in field using randomize complete block design with three replications in the research area of Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad. Traits under study were plant height, total number of tillers, spike length, spikelets per main spike, number of grains per spike, weight of grains per spike, peduncle length, number of fertile tillers per plant, 1000-grain weight and grain yield per plant. Analysis of variance showed highly significant differences among all genotypes for all traits. The Wr/Vr graphical representation indicated that additive type of gene action with partial dominance governed the inheritance of plant height and peduncle length, emphasis that the pedigree selection is promising approach for further improvement of these traits. While over dominance was observed for spike length, grains per spike, productive tillers per plant, spikelets per main spike, 1000 grain weight, tillers per plant, weight of grains per spike and grain yield per plant suggesting heterosis breeding might be fruitful for further improvement.