Abstract: The sap flow rate of Hippophae rhamnoides L. subsp. sinensis Rousi in Huangfuchuan Basin was measured by using thermal dissipation probe method, and the related environmental factors such as incident solar radiation, air temperature, relative air humidity, wind speed, and soil temperature at the depth of 10 cm were recorded continuously by using automatic weather station. At the same time, the leaf transpiration rate during 6:00-18:00 was also measured by LI-6400. The results showed that in the period of no rainfall, the sap flow rate of H. rhamnoides varied regularly, with higher value in daytime than in nighttime and more apparent fluctuation in daytime than in nighttime. The sap flow rate increased significantly at the beginning of rainfall, but after then, it descended and became steady. Taking the incident solar radiation, air temperature, relative air humidity, wind speed, and soil temperature at the depth of 10 cm as independent variables and the sap flow flux per unit dry foliage mass as dependent variable, a multiple linear equation was established by stepwise regression, and the regression was significant.

Key words: Environmental conditions, Phytochelatins, Cd biotoxicity, Triticum aestivum