金钟藤和葛藤在干旱与复水条件下的生理比较

对外来入侵种金钟藤和本地种葛藤进行干旱胁迫和水分恢复处理,比较了两种植物抗氧化酶(SOD、CAT)活性、丙二醛(MDA)含量及叶绿素荧光参数的变化。研究表明,干旱胁迫下两种植物SOD、CAT活性均高于复水后,金钟藤高于相同处理下的葛藤;金钟藤在干旱与复水条件下的MDA含量无差异,而葛藤干旱下高于复水后,不同处理下葛藤均高于金钟藤;干旱条件下金钟藤比葛藤有更强的抗氧化能力,膜脂过氧化水平明显较低,MDA与SOD、CAT呈明显的负相关。两种植物在复水后Fv/Fm、ETR与ΦPSⅡ值均显著高于干旱时,葛藤变化程度略大于金钟藤。复水后金钟藤的NPQ值增加而葛藤降低,且干旱时葛藤大于金钟藤,复水后金钟藤大于葛藤。综合比较,金钟藤比葛藤对干旱的生理适应能力强,这可能是其入侵性的重要特征。

Physiological compare Merremia boisiana with Pueraria lobata under drought stress and rewatering conditions

The activities of antioxidant enzymes,such as superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA)content and chlorophyll fluorescence parameters were compared between invasive exotic plant Merremia boisiana and native plant Pueraria lobata under drought stress and rewatering conditions. The results showed that SOD and CAT activities of these plants under drought stress were higher than that after rewatering,and M.boisiana had stronger enzymes activities than P.lobata under same treatments. The difference of MDA content was not evident after drought and rewatering treatments in M.boisiana,while MDA content in P.lobata under drought stress was higher than that of rewatering treatments. Moreover,MDA content in P.lobata was higher than that of M.boisiana under different treatments. These results indicated that M.boisiana had stronger antioxidant activities under drought stress,and its membrane lipid peroxidation level was obviously low. As a result,MDA content was evidently negative relative to the activities of SOD and CAT. Chlorophyll fluorescence parameters Fv/Fm,ETR and ΦPSⅡ after rewatering were significantly higher than that of drought treatments,and the changes of the parameters in P.lobata were a little evident than that in M.boisiana. The value NPQ of M.boisiana rose while that of P.lobata reduced after rewatering,and the latter was higher than the former under drought stress. In contrast,M.boisiana was higher than P.lobata after rewatering. Summarily,it was analyzed that M.boisiana possessed stronger physiological adaptability to drought than P.lobata,which was possibly an important invasive characteristic.