The Effect of Drought Stress on Physiological Traits in Lines and Cultivars of Bread Wheat (Triticum aestivum L.)

All around the globe, drought is considered one of the critical threats putting agricultural industries at stake. With such impediments existing, challenges of feeding the population arise. This study evaluated and selected appropriate wheat cultivars with desirable traits. The objective was achievable by accurately assessing quality traits and resistance characteristics under simulated drought-stress conditions. From ۲۰۱۸ till ۲۰۲۰, six cultivars were evaluated using a split-plot design with three repetitions. The study consists of a control plot (regular irrigation throughout the growing season; zero drought stress), moderate drought stress (irrigation halted before booting stage), and complete drought stress. According to the results, the intensity of drought stress has statistically significant impacts on quality traits; in other words, the content of soluble sugars, protein, and proline were affected. Furthermore, alternations in enzyme functions, such as peroxidase and polyphenol oxidase, were observed. The leaf protein content declined under moderate and full drought treatments (-۵۵% and ۷۱%, respectively). However, a significant increase was detected in total soluble sugar (۴ and ۱۰%, respectively) and proline content (۲۶ and ۴۵%, respectively), along with intensified enzymatic functions for peroxidase (۱۰ and ۲۲%, respectively) and polyphenol oxidase (۴ and ۱۰%, respectively). According to the results, certain biochemical traits should be taken into account when selecting drought-tolerant wheat varieties. The most durable cultivar was N-۹۳-۱۷, with the highest yield potentials, followed by Tirgan in terms of water deficiency. Rank sum analysis identified the most drought-tolerant cultivars as ‘N-۹۳-۱۷’ and ‘Aftab’. Results of this investigation would be of great importance in selecting desirable parents for the breeding program to develop wheat cultivars resistant to drought stress conditions

کلیدواژه ها:

Drought stress ، Peroxidase enzyme activity ، Polyphenol oxidase enzyme activity ، Proline content ، Protein content