Researches on drought resistance of mulberry trees applied to vegetation recovery engineering in Chongqing Section of the Jialing River Basin, China

摘要

To examine possible effects of soil water conditions in summer in Chongqing section of Jialing River Basin on mulberry trees, we grew potted mulberry in a greenhouse under three soil water regimes designed to simulate normal irrigation (CK), moderate drought stress (T1) and extraordinary drought stress (T2). The results showed the following. 1) With drought stress increasing, the heights, base diameters and root biomass all decreased significantly. The root/shoot ratio, specific root area and root activity of mulberry on the whole showed an increasing trend as drought stress increasing. The leaf water potential of mulberry after drought stress on the whole decreased significantly compared with CK; 2)With the elongation of treatment time, the heights, base diameters root biomass and root/shoot ratios of mulberry in the three treatment groups still increased to different degrees. The root activity of mulberry in each treatment group first increased and then decreased basically, but still maintained a higher level compared with CK, moreover, the leaf water potential of mulberry also decreased gradually on the whole. We concluded that under drought stress conditions the growth of mulberry will be inhibited in a way, but the plant can actively improve its absorption ability by some ways, thereby maintaining its normal physiological metabolism, accordingly demonstrating strong drought resistance.