Direct and Indirect Selection for Grain Yield in Bread Wheat (Triticum aesitivum L.)

Abstract

Direct and indirect selection for grain yield through 1000grain weight, spikelet fertility and spike density were achieved in bread wheat at the Exper. Farm Fac. Agric., Minia Univ. Egypt during the three successive seasons of 2016/17 to 2018/19. After two cycles of pedigree selection phenotypic variation of grain yield/plant, 1000grain weight, spikelet fertility and spike density decreased rapidly from F2 base population to F4. Indirect selection through high 1000 grain weight resulted in the highest grain yield/plant (23.62g) followed by direct selection for grain yield/plant (20.66 g). Average direct gain for the ten selected families of direct selection for grain yield showed highly significant increase in percentage of the bulk sample of 62.95% and the better parent of 39.25%. Pedigree selection was effective in detecting the high yielding families. Family No. 145 gave significant (P≤0.01) grain yield in percentage of the better parent and bulk sample by 77.09 and 107.23%, respectively. Average direct response in percentage of the bulk sample was significant and reached 21.08% for 1000 grain weight, 31.12% for spikelet fertility and 7.27% for spike density. Three families; No. 15, No. 72 and No. 153 surpassed significantly the bulk sample by 33.83, 43.01 and 29.28%, respectively, when selection practiced for 1000 grain weight. Family No. 145 considered to be a promising line in grain yield and spikelet fertility. High strong positive genotypic correlation was found between grain yield with each of weight of spikes/plant (0.81), no. of grains/spike(0.71), weight of grains/spike (0.91), 1000grain weight(0.92) and spikelet fertility(0.70).