Abstract: The responses of different leaf age seedlings to water deficit for two cultivars (Shanyou 63 and Wuyujing 2) were studied in test pots. The whole process from growth stagnate, leaf curl to seedling death was observed. The results show that the sensitivity and tolerant ability to water deficit have obvious difference at different leaf stages of rice seedling. Besides extreme sensitiveness at bud stage, the sensitivity of seedling to water deficit enhances with leaf age increase, but tolerant ability is the most weak at stage of 2-3 leaf age of seedling. These response differences above-mentioned depened mainly on the size of leaf area of seedling, cultivar types and thickness of soil layer.

Key words: Leaf age, Unflooded seedling, Water deficit

关键词: 水稻, 秧苗, 叶龄, 缺水反应