Water potential with Phyllostachys edulis in its fast-growth periods

To determine whether 1） water transport from mature to young Phyllostachys edulis bamboo and 2） water potential were key factors driving growth of young Ph. edulis in its fast-growth period, a PSYPRO water potential system with L-51A leaf water potential probes and PCT-55 soil potential probes were used to measure leaf and soil water potential at the physiological-ecological monitoring station of Zhejiang A F University. Analysis included analysis of variance（ANOVA）, Turkeys test for multiple comparisons and a correlation analysis. Results for the period of rapid growth with new to six-year-old Ph. edulis bamboo showed that the water potential value significantly increased （P ＜ 0.05） with an increase in age. Leaf water potential of same-aged bamboo was lower in the rapid growth period than before and after. However, among mature Ph. edulis, leaf water potential differences in the rapid growth period were not significant. Also, during the rapid growth period correlation of water potential to soil-leaf （P = 0.627）, soil-atmosphere （P = 0.908）, and leaf-atmosphere （P =0.716） were all highly significant （P ＜ 0.01）. Thus, existence of a strong water potential gradient meant that a key factor with mature Ph. edulis water transport to young Ph. edulis mainly relied on the water potential gradient for driving fast-growth.［Ch, 5 tab. 21 ref.］