| Chamber cultured and pot experiments were used to evaluate the effects of soaking seeds with Chlormequat (CCC) on the germination, seedling growth and water use efficiency of different wheat cultivars. The results showed that, in chamber cultured experiment, the germination ratio (GR), germination index (GI), and dry weights of shoot and root of Xiaoyan 22 and Shaan 229 were increased by soaking seeds with low concentration of CCC (≤10.0 g/kg); these parameters were obviously decreased when the concentration of CCC was high (>50.0 g/kg); compared to Shaan 229, Xiaoyan 22 was more sensitive to high concentration of CCC. In pot experiment, soaking seeds with CCC increased the content of chlorophyll in leaves and photosynthetic rate of Xiaoyan 22 and Xiaoyan No. 6, and also improved the root growth and dry matter accumulation. The effects of soaking seeds with CCC on water use efficiency were related with wheat cultivars and soil water content. The increase rate of water use efficiency of Xiaoyan 22 was higher than Xiaoyan No.6 under normal water condition; but it was reverse under water stress condition, and the increase rate of water use efficiency of Xiaoyan No. 6 was the highest when the seeds were soaked with the concentration 2.0 g/kg of CCC. The adequate concentration of CCC was 2.0 g/kg for both chamber cultured and pot experiments. |