h. modarse zade

Water stress is the main limitation in the production of many crops and causes many physiological and morphological reactions in plants. This problem has been observed in different cultivars of the same species, including soybeans. The aim of this research was to study the effect of water stress on water relations, proline content and morphological characteristics of two soybean cultivars including Pershing and DPX. For this purpose, an experiment was carried out in pots and water treatments of 80 (flooded), 60, 40 and 20% (dry) of the water saturation capacity of the soil were applied on them. The results of the studies showed a significant difference in the measured measurements in two soybean cultivars. In both cultivars, reducing the amount of irrigation caused a decrease in plant height and root length, and in the flooding treatment, it was associated with a significant increase in misplaced roots. In the Pershing variety, the decrease in the amount of irrigation led to a decrease in the relative amount of water (RWC), but in the DPX variety, the lowest amount of RWC was observed in the 40% treatment. Leaf water loss (LWL) was higher in all treatments in Pershing variety than similar treatments in DPX variety. The highest amount of proline in leaves and roots was related to treatments with lower RWC, which was observed in Pershing and DPX cultivars in 20% and 40% treatments, respectively. In both cultivars, the amount of proline amino acid was higher in the leaves than in the root. The results showed that in both cultivars, leaves were more affected by water stress than roots, and Pershing cultivar showed more sensitivity in low water levels.