"To examine possible effects of soil water conditions in summer in the hydro-fluctuation belt of the Three Gorges Reservoir Area on mulberry, we grew potted mulberry in a greenhouse under three soil water regimes designed to simulate normal irrigation (CK), moderate drought stress (T1) and elevated drought stress (T2). The results showed the following.1) With drought stress increasing, the heights, base diameters, and root surface areas of mulberry trees decreased significantly relative to the corresponding earlier period. The root / shoot ratio increased gradually in the earlier stage, and decreased gradually in the later stage. The specific root area of mulberry trees on the whole increased significantly relative to the corresponding earlier period. 2) With the elongation of treatment time, the growth of mulberry seedlings decreased gradually, and the heights, base diameters, root surface area and root / shoot ratio of the mulberry trees in the three treatment groups increased to different degrees. The specific root area of mulberry trees on the whole decreased gradually. We concluded that under the different degrees of drought stress the growth of mulberry trees would be inhibited, but the plants were also able to adapt to the stress, thereby maintaining physiological and metabolic viability. Biomass appeared to be re-allocated such that
water absorption capacity was improved. Accordingly it can be concluded that the mulberry trees demonstrated potential for resisting and tolerating drought stress."