The effects of altitude and growing season on the physiological characteristics of Kobresia pyg-maea were investigated by analyzing the physiological indices in its leaves and roots during different phe-nological stages and altitudinal gradients in the Qilian Mountains.The results showed that the malondial-dehyde(MDA)and soluble sugar(SS)content in the leaves were highest in September,while the proline(Pro)content highest in June.In the later growth stage,the activities of superoxide dismutase,peroxidase and catalase decreased,and the MDA content in the roots also decreased,while the SS and Pro content increased.The activities of the three antioxidant enzymes increased in the later stages of growth.The physiological indicators in the leaves were higher than those in the roots during different growth periods.The temperature for the highest comprehensive efficiency of physiological factors in the leaves and roots were different with regard to the temperature of stress,indicating that the organs had significant effects on the osmoregulatory substances and antioxidant enzyme activities.A comparison of cold resistance in different growth seasons of K.pygmaea under different temperature stresses revealed a pattern of Sep-tember＞June＞July＞August.With increasing altitude,the leaves of K.pygmaea showed greater sensitivity to low temperatures,while the roots exhibited stronger antioxidant capabilities in the later stages of growth.There were considerable differences between the leaves and roots at the same altitude during different growth seasons.Although plants growth in high-altitude areas exhibited various physiological adaptation features,their membrane systems were still somewhat affected by the cold environment.
维普
万方数据
