三种湿地植物抗寒性的初步研究

Preliminary Study on Cold Resistance of Three Kinds of Wetland Plants

在阶段性降温条件下,研究了三种常用湿地植物黄鸢尾(Iris pseudacorus L.)、花菖蒲(Iris ensata Thunb.)及水芹(Oenabthe javanica)叶片抗寒性相关生理指标(可溶性蛋白质含量、可溶性糖含量、游离脯氨酸含量、丙二醛含量、超氧化物歧化酶活性、过氧化物酶活性、过氧化氢酶活性以及细胞质膜相对透性)的变化。结果表明,冷锻炼使湿地植物通过对抗氧化酶活性及渗透性的调节来提高其机体的抗寒性。低温条件下,黄鸢尾的抗氧化酶活性显著增加,5℃时SOD活性是初始值的5.77倍;花菖蒲保持较高的CAT活性,5℃时其CAT活性是黄鸢尾CAT活性的8.95倍,是水芹CAT活性的3.77倍;水芹叶片中脯氨酸含量明显提高,温度和脯氨酸含量呈负相关(R=-0.755,P=0.050)。综合比较各项生理指标可以得到这三种湿地植物的耐寒性大小顺序依次为:黄鸢尾>花菖蒲>水芹。

This paper investigated the effect of temperature grading decrease on cold resistance of three kinds of common wetland plants：Iris pseudacorus L.,Iris ensata Thunb.and Oenabthe javanica.Changes in cold resistance of the plants were reflected by some physiological in-dexes.The physiological indexes included soluble protein,soluble sugar,proline,EL,MDA,SOD,POD and CAT.The results showed that cold resistance of the plants was improved in the process of cold hardening by adjusting antioxidant enzyme activities and permeability.The step by step cooling brought about changes in some cold resistance related enzymes and permeability regulatory substances.In addition,dif-ferent species showed different change law in physiological indexes.Antioxidant enzyme activity of Iris pseudacorus L.increased obviously in low temperature.SOD activity of Iris pseudacorus L.at 5 ℃ was 5.77 times higher than the initial value.CAT activity of Iris ensata Thunb.maintained a high level,and it was 8.95 times and 3.77 times more active than that of Iris pseudacorus L.and Oenabthe javanica respectively at 5 ℃.Concentration of proline of Oenabthe javanica remarkabley increased and it was negative related to temperature（R=-0.755,P= 0.050）.After a comprehensive comparison of all the indexes,the cold resistant ability could be ranked as follows：Iris pseudacorus L.Iris ensata Thunb.Oenabthe javanica.