不同冬小麦对盐处理和干旱胁迫交互作用响应的差异性分析

通过对抗逆性不同的6个烟台冬小麦品种在盐处理和干旱胁迫交互作用进程中叶片相对含水量（RWC）,膜脂过氧化产物（MDA）和抗氧化酶活力（SOD,POD,CAT）及渗透调节物含量（脯氨酸,可溶性蛋白）的分析,以了解不同冬小麦品种对盐处理和干旱胁迫交互作用响应的生理调节差异。研究表明,在水分供应充足条件下盐处理10 d,6个品种冬小麦生长良好并和对照没有差异,但在干旱胁迫中盐处理组较对照MDA含量低,RWC和抗氧化酶活力和渗透调节物含量均高,且叶片萎蔫较对照出现晚。但经盐处理的6个冬小麦品种对干旱胁迫响应有差异。在长期干旱(12 d),抗旱性强的品种RWC（81%）明显高于抗旱性弱的（62%）,前者叶片MDA含量较后者低30%,抗旱性强的品种抗氧化酶活力和渗透调节物含量略低于抗旱性弱的品种,但是差异不明显。在盐处理和干旱胁迫交互作用下,盐离子自身可作为渗透调节物既增加了土壤的持水力又提高了细胞保水力而使冬小麦耐旱性增强。抗旱性强的冬小麦品种对盐处理反应敏感且保水性强,细胞膜脂过氧化程度较低,故耐旱力高,抗旱性弱的品种则相反。研究进一步表明,在未来干旱地区实施适度的盐水灌溉可提高冬小麦的耐旱力,但选择抗旱力强的冬小麦品种是实施这一农业耕作措施的关键。

Responses of Different Winter Wheat Cultivars to Sodium Salt and Drought Treatments

Variation in physiological regulation in response to interaction of salt treatment and drought stress in leaves of six winter wheat cultivars (Triticum aestivam) was studied by measuring the contents of relative water content (RWC), malondialdehyde (MDA), proline and soluble protein, and activities of antioxidant enzymes(SOD, POD, CAT). Results showed that the six winter wheat cultivars with 1.0% NaCl treatment for 10 days under well water supply grew well as control, and there were no significant physiological differences among them. But under drought stress for 12 days, six winter wheat cultivates treated with salt had lower MDA content, higher RWC, higher activities of antioxidant enzymes and higher contents of proline and protein than control without salt treatment. Leaves with salt treatment wilted later than control. While there were different responses to salt treatment and drought stresses for six winter wheat cultivars. In 12 days of drought stress, tolerant cultivars had higher RWC (81%) than susceptible cultivars (62%), and lower MDA contents (decreased by 30%), lower activities of antioxidant enzymes and lower content of protein and proline than susceptible cultivars. But there were no significant diffidence among the winter wheat cultivates. Under interaction of salt treatment and drought stress, it is likely that salt would be a permeable matter to increase winter wheat tolerance to drought by enhancing ability of soil water-holding and leave water-maintaining. Tolerant cultivars of winter wheat had higher ability of salt uptake in leaves under salt treatment, which would result in stronger water-maintaining of tolerant cultivars of winter wheat under drought stress, and lower MDA and lower activities of antioxidant enzymes than susceptible cultivars. This study further indicated that irrigating saline water in arid area can improve winter wheat drought tolerance, but it is a key to select the drought tolerant cultivars in successful agricultural output by irrigating saline water.