PERFORMANCE AND STABILITY OF PROMISING BREAD WHEAT LINES

Abstract

The present study was conducted to evaluate 40 promising bread wheat lines compared to their 4 parents and 6 commercial cultivars for their productivity and estimating stability under eight environmental conditions. Wheat genotypes were sown on two planting dates (14 November “recommended date” and 13 December “late sowing date”) under two nitrogen fertilization treatments (Biofertilizer + 40kg N/fed. and 80kg N/fed.) in two growing seasons (2018/2019 and 2019/2020) at the Experimental Farm of the Faculty of Agric., Ain Shams Univ. at Shalakan, Kalubia Governorate. The results revealed that the mean squares of genotypes, sowing dates, and nitrogen fertilization treatments were significant for grain yield and its contributions (days to heading, flag leaf area, plant height, number of spikes/plant, spike length, number of spikelets /spike, number of kernels /spike, 1000-kernel weight and grain protein content), indicating that these characters are influenced by factors used in this investigation. Yield and yield contributes increased by planting wheat genotypes at the recommended sowing date in mid-November under optimum nitrogen levels (80 kg N/fed.). Conversely, planting under delayed sowing dates and low nitrogen conditions led to a drastic reduction in grain yield/plant and its contributes. The mean squares of environments were highly significant for all studied traits, suggesting that the environments affected differently the wheat studied traits. Environment (E) + (G x E) and pooled deviation were highly significant for all the studied traits except flag leaf area (cm2) for pooled deviation, indicating the presence of genetic differences among genotypes for their regression on the environmental index. This study revealed that the lines number 9, 10, 11, 26, 27, 28, 29, 30, 31 and 33 gave high mean values for grain yield and its contributions and exhibited general adaptability across different environments; thus, such lines are considered to be promising genotypes and could be used in breeding programs for wheat improvement.