Characterization of Bread Wheat Genotypes Using Morpho-Phenological Attributes Related to Yield Under Terminal Heat Stress

Owing to the fluctuations in environmental conditions warrants wheat scientists to develop new heat tolerant cultivars which can significantly increase and stabilize wheat production. For the assessment of genetic variability, twenty wheat genotypes were evaluated to improve their yields under the climate change scenarios. The experiment was conducted at the experimental area of Department of Plant Breeding and Genetics, The Islamia University of Bahawalpur, Pakistan under randomized complete block design following factorial arrangement with three replications. Variety × Treatment × Year interaction of wheat genotypes was studied for various morpho-phenological traits under normal sowing and late sowing conditions for two years in field. Highly significant differences were found among all the genotypes for all traits. Stronger correlations among the studied traits under terminal heat stress over normal further revealed heat stress adversities. The eigenvalues of first three principal components (PCs) were greater than 1 therefore considered as significant explaining 68.50% and 57.33% cumulative variability present in genotypes under normal and late sowings, respectively. The PC biplots showed yield per plant with maximum variability with maximum length of the vector than rest of the parameters. SUBHANI-21 showed maximum yield and number of tillers per plant followed by LASANI-08 and UJALLA-16 for thousand grain weight under heat stress. Selection of the positively associated traits would be fruitful and the tolerant genotypes having heat stress tolerance potential could be utilized in future wheat breeding programs to develop high yielding and heat resilient genotypes.