شناسایی تیپ ایده‌آل کلزا در شرایط تنش خشکی براساس صفات مورفوفیزیولوژی

In order to identify of effective traits in drought stress tolerance at Rapeseed, experiments were conducted at two locations, Shahre Qods-Shahriyar (semi-arid region) and Yazd (arid region) in 2011-2012. In this study, four commercial Rapeseed genotypes (GKH2005, Opera, Okapi and SLM046) were examined from drought tolerance at stem elongation, flowering, silique formation stages in four separate experiments based on randomized complete block design. The results indicated that the suitable ideotype for treatment of irrigation withholding from stem elongation until physiologic maturity was defined as a plant with shorter growth period, higher catalase enzyme activity, great relative water content and stomata conductivity, higher silique number per secondary branch and great remobilization. Under conditions of irrigation withholding from flowering until physiologic maturity, some characteristics such as higher peroxidase enzyme activity, great stomata conductivity, proline accumulation, high silique number per secondary branch, high remobilization efficiency and lower secondary branch number and lipid peroxidation were more effective in drought tolerance. In contrast, suitable ideotype for treatment of irrigation withholding from silique formation until physiologic maturity was defined as a plant with higher peroxidase enzyme activity, great leaf stomata conductivity and high remobilization efficiency, shorter growth period, low secondary branch number and higher silique number per secondary branch which have a low silique length.