Abstract: Three paddy and upland rice cultivars were treated by drought stress at the heading-filling stage, of them Xiangjing 2 (paddy rice, japonica) had more free water in leaves under drought stress, still maintained the membrane permeability at a higher level and the bound water in leaves declined when the plants regained water irrigation and its mean grain yield decreased by 37. 5 %, a minimum in the three cultivars. As to Qin'ai (upland rice), the properties relevant to grain yield were almost not affected by gentle drought stress and showed the resistance to it to a certain extent, its membrane permeability was very low in the leaves of the plants regained water. Xiangzhongxian 3 (paddy rice, indica) displayed the physiological changes contrary to Xiangjing 2 and its mean grain yield dropped by 71. 4%, so it was highly sensitive to drought stress.

Key words: drought stress, membrane permeability, paddy rice, upland rice, yield component

摘要： 在开花灌浆期对三个水、陆稻品种进行干旱胁迫处理。结果发现，叶片中自由水含量较高的湘粳2号（粳型水稻）在复水后细胞膜透性仍然较高，束缚水含量下降，平均减产幅度最小，表现出明显的耐旱特性。而湘中籼3号（籼型水稻）的表现相反，是不耐旱品种。陆稻品种奉爱的抗旱性明显较强，但产量较低，有待进一步改良。

关键词: 干旱胁迫, 水稻, 陆稻, 膜透性, 产量性状