Correlation, Path and Regression Analysis in Some Bread Wheat (Triticum aestivum L) Genotypes under Normal Irrigation and Drought Conditions

THE OBJECTIVE of this study was to assess correlation, path and regression analysis in 39 F6 bread wheat (Triticum aestivum L) genotypes during two seasons, i.e., 2015/2016 (F7) and 2016/2017 (F8) under irrigation and drought stress conditions at Fac. Agric. Edu. Farm, Minia University, Egypt. A positive correlation was found between grain yield and each of the number of spikes/plant and number of grains/spike under the two conditions. Path analysis revealed high positive direct effects on grain yield/plant via the number of grains/spike (0.929) under irrigation and number of spikes/plant (0.973) under drought. The direct effect of 100-grain weight on grain yield/plant was positive under irrigation (0.649) and drought (0.260). The indirect effects of these traits were negative under the two conditions. Stepwise regression analysis revealed that three models no. 8, 9 and 10 were fitted for each environment. The model no. 8 included one trait; the number of grains/spike under irrigation and number of spikes/plant under drought. Its relative contributions in grain yield were 0.180 and 0.693 under irrigation and drought; respectively. The model no. 9 in the two environments included two traits; the number of grains/spike and number of spikes/plant, its relative contributions in grain yield/plant were 0.544 and 0.836 under normal and drought conditions, respectively. The model no. 10 included three traits number of grains/spike, number of spikes/plant and 100-grain weight, its relative contribution in grain yield/plant were 0.0.931 and 0.978 under normal and drought conditions, respectively. This model no. 10 is fit and superior to use in selection for grain yield/plant.