PHYSIOLOGICAL AND BIOCHEMICAL RESPONSES OF WHEAT SPECIES WITH DIFFERENT PLOIDY LEVEL UNDER DROUGHT STRESS

Drought is crucial abiotic stress that limits growth and causes a yield reduction in wheat, So, the identification of susceptible and tolerant wheat curtivars to drought is critical for breeders. In this study, physiological and biochemical responses against drought stress were investigated in wheat varieties, Siyez (Triticum monococcum), Kiziltan-91 (Triticum turgidum) and Yaregir-89 (Triticum aestirum) possessing different ploidy levels. Some growth, physiological parameters (membrane permeability, malondialdehyde. H2O2, proline and ascorbic acid) and antioxidant enzyme activity (SOD, CAT, APX and GPX) analyses were performed. The first effect of drought was the increase in root lengths for all species. Ascorbic acid and proline amount raised in roots and shoots at a maximum in Yilregir-89 and at a minimum in Siyez. An increase in the CAT activity was observed in the roots of Ytiregir-89 and in the leaves of Kiziltan-91. Similar defensive patterns of SOD and GPX enzymes were monitored in Ytiregir-89 and Kiziltan-91 tissues. Genotypic variation arisen from ploidy level contributed by various parameters was also determined by principal component (PCA) analysis under drought stress, As a result of all analyses, Kiziltan-91 and Ytiregir-89 wheat varieties could be considered as resistant to drought and Siyez wheat was susceptible to drought. The possible explanations for this might be strong enzymatic and non-enzymatic antioxidant defense mechanisms and high ploidy levels mechanisms in Kiziltan-91 and Ytiregir-89 varieties, This study has the potential to become a reference source for studies of the identification of wheat species with a high survival rate under drought in the future.