冬季凤眼莲对盐胁迫的盐害表现及生理响应

Salt Injury Symptoms and Physiological Response of Eichhornia crassipes to Salt Stress in Winter

通过模拟试验,探讨了冬季凤眼莲在不同盐胁迫中的盐害表现及生理响应,以期获得其最高耐受的盐度范围,充分发挥凤眼莲在修复河口、内陆咸水湖等污染水体应用中的净水作用。试验设置5、10、14、18、21的盐度梯度,以不添加海盐为对照组进行试验。结果表明,冬季凤眼莲在5和10的盐胁迫下以叶片形态损伤为主,叶片外缘失水卷曲,之后逐渐枯黄,在10的盐胁迫下植株表现出牺牲局部来维系生命的被动适应策略。而在14及更高盐度的环境中,凤眼莲叶柄会因失水而表现为膨压降低,软化倒伏,叶片出现大量失绿的伤斑,之后快速枯黄,其SI不断升高,培养11 d后均达到90%以上。盐胁迫使凤眼莲叶片的细胞膜膜脂过氧化反应加剧,MDA含量增多,表现出SOD活性显著提高以增强自身抗氧化能力,合成并积累Pro以减小水势等的应对策略,而POD活性对盐胁迫不敏感。凤眼莲自我调节能力有限,冬季可耐受的最高盐度可能在10~14之间。

In this paper,simulation experiments were carried out in winter to investigate the salt injury symptoms and physiological responses of Eichhornia crassipes in different salt stress.And the maximum tolerant salinity range was obtained to give full play of E.crassipes the purification effects of polluted water bodies such as estuaries and inland saltwater lakes.In the experiment,the experimental group was set up 5,10,14,18,21 as salinity gradients and the control group was not added salt.It showed that primary injury occurred in leaves of E.crassipes at salinity of 5,10 in winter.Some leaves rolled up and appeared obvious dehydration,and then withered gradually.At salinity of 10,E.crassipes survived with passive adaptation strategy of partial sacrifice.When salinity was equal or greater than 14,however,most petioles of plants were turned to low turgor pressure and leaned resulting from water loss,and leaves appeared scars of losing green,then quickly withered and yellow, which caused that SI reached more than 90% after 11 days. With increasing salinity themembrane peroxidation of leaves became violent resulting in increasing content of maletic dialdehyde (MDA),meanwhile the activity of superoxide dismutase (SOD) significantly increased to improve antioxidant capacity,and proline (Pro) was synthesized and accumulated to reduce water potential, but the activity of peroxidase(POD) was not sensitive to salt stress in winter. Generally, E. crassipes has limited self regulating ability insaline water, and the maximum tolerate salinity in winter may be between 10-14.