Abstract: Using 4 rice varieties, the dynamic changes of several biological characteristics were studied under different degrees of water saving treatment at tillering stage. The results showed that rice plant could change the transfer of organic matter and root characters to alleviate drought harm in the course of and after water saving treatments, suggesting strong self-adjustment ability. Water saving treatment reduced water consumption of rice plant in the course of treatment and after treatment, but the difference between rice varieties was significant or highly significant. Suitable drought at tillering stage could enhance water use efficiency (WUE) of rice plant significantly in the course of and after treatment. The differences in yield and rice quality between rice varieties in various water saving treatments were significant or highly significant. The effects of water saving treatments on yield and quality depended on rice varieties, suggesting that it is very important to select rice varieties in water saving cultivation.

Key words: Rice, Water saving cultivation, Biological characteristics