لیلا کرمی

Dehydration stress is a non-living stress that seriously affects the production of agricultural products in most parts of the world. This study was conducted to evaluate the water stress tolerance in nine of early, medium and late mature maize cultivars, including (260kcs, 570zp , 670zp, 606zp, 704ksc, 640zp, maxima, valbom, 703kcs) the experiment was a complished in randomized complete block design with three replications in 2017 year under three levels of irrigation regimes, normal water stress (normal irrigation), moderate water stress (Irrigation cut from the ear formation stage), severe water stress (Irrigation cut off from the stage of 50% flowering), in the field conditions of the Faculty of Agriculture and Natural Resources of Dashtestan. The evaluated traits was included weight, length and diameter of the ear, number of rows and number of seeds per row, Thousand seed weight, grain yield, harvest index, proline, chlorophyll a, b and total, catalase enzymes, peroxidase, superoxide dismutase, and protein. Simple and compound analysis of variance and comparison of meanings by Duncan method and correlation analysis using SAS statistical program. The results showed that there was a significant difference between the cultivars for most of the traits at a probability level of One percent. In all cultivars, the changes in the weight traits, thousand seed weight, grain yield per unit area, ear length, ear diameter, number of seeds per row, number of rows per ear, protein, and harvest index from normal irrigation to severe stress levels Water was reduced in the 50% flowering stage, but increased for catalase, peroxidase, superoxide dismutase and proline enzymes. The results showed that cultivars 704ksc, 260ksc, 703ksc and maxima had the highest grain yield in three levels of water stress, and were identified as the most resistant cultivars to water stress, 670zp and 570zp cultivars with the lowest grain yield Three levels of stress were identified and identified as th