PHYSICAL AND MORPHOLOGICAL MARKERS FOR ADAPTATION OF DROUGHT-TOLERANT WHEAT TO ARID ENVIRONMENTS

The threat of climate change has instilled a demand for multi-faceted genetic diversity coupled with resourceful tools and technologies to attain biotic and abiotic resistance in crops. The present study was designed to investigate and compare common physiological and morphological traits under normal and water-stressed conditions. Seven selected (Pakistani, Indian and CIMMYT) water stress-tolerant (WST) genotypes were crossed with seven local water stress-susceptible (WSS) lines using a line × tester mating approach. The hybrids, together with parents, were sown in two different environments. Combining ability effects determined the behavior of both parents as well as offspring and allowed the best combiners for different traits to be selected. Different traits showed additive and non-additive types of gene action under both environmental conditions. The present study concluded that genotypes Nesser, Dharwar Dry, Inqilab-91, among others, served as good combiners while Bakhar-2002 × 9247, Dharwar Dry × 9021, Bakhar-2002 × 9244, and Nesser × 9244 are promising cross combinations. Regarding grain yield, genotype 9252 and Dharwar Dry performed best under normal irrigation and water-stressed conditions, respectively. A change in water provision resulted in a shift in gene action, broad sense heritability and proportional share that each trait contributed. When these traits were pooled, it was possible to discriminate between WST and WSS genotypes and, through line × tester experiments, develop drought- and water stresstolerant lines based on morphological markers under changing climatic conditions.