COMPARATIVE STUDY ON THE RESISTANCE OF Kobresia humilis GROWN AT DIFFERENT ALTITUDES IN QINGHAI XIZANG PLATEAU
青藏高原不同海拔矮嵩草抗逆性的比较研究

The paper reports comparative studies on the physiological ecological adaptiveness of K. humilis grown at different altitudes (Daban Mt.4000m a.s.l.; HaiBei station 3200m a.s.l.and Xizang 2200m a.s.l.) in Qinghai Xizang Plateau. Results showed that growth and matter accumulation of K.humilis at different altitudes had obvious differences. Plant height, leaf area, content of chlorophyll and dry matter of plants tended to decrease with increasing altitude. the content of carotentoid and flavonoid, photosynthetic rate, light compensation point and light saturation point of plants increase with increasing altitude, and photorespiration rate declined. The content of sucrose, fructose, glucose and the total soluble sugar of aboveground tissue of plants grown at Daban Mt.increased by 65.4%, 110.2%,121.6% and 84.6%,as compared with that of Haibei station respectively during exuberance. The belowground tissue increased by 5.6%,17.8%,88.6% and 43 8% respectively. In addition, the content of sucrose, fructose. glucose and the total soluble sugar of belowground tissue of plants from Dabann Mt.and Haibei station was higher than that of aboveground tissue during winthering I. At the smae time, the peroxidase activity in the leaf of plants from Daban Mt.and Haibei station was increased 90.0% and 28.1% in average than that of Xining respectively. The results demoustrated that plants grown at higher altitude in Qinghai Xizang Plateau possess stronger resistance and adaptiveness. It is clear that the physiological ecological characteristics of K.humilis were associated with its specific structure, with increase of cold resistant matter and peroxidase activity.