不同香稻品种苗期耐高温的形态生理响应

【目的】本研究旨在分析不同香稻品种苗期耐高温的形态生理响应特征,筛选出耐热性较好的香稻品种。【方法】在盆栽条件下,于光照培养箱内,以超级常规香稻玉香油占为对照,研究了常规香稻品种巴斯马蒂、桂香占、农香18、湘晚籼13、象牙香占、中香1号、美香占2号在苗期高温处理下的形态生理响应特征。于高温处理前后测定了8个香稻品种苗期各项形态生理指标。【结果】与玉香油占相比,高温胁迫下,巴斯马蒂的株高、单株鲜质量、单株干质量增幅更大,成活率和过氧化物酶活性更高,丙二醛含量反而下降了33.39%,表明巴斯马蒂的耐高温胁迫能力较好。湘晚籼13在高温处理下的单株干质量增幅与玉香油占相近,株成活率较玉香油占低,胞间二氧化碳浓度变幅较小,SOD活性和丙二醛含量的变幅在8个品种中均为最低,说明其耐高温胁迫的能力略低于玉香油占。农香18、象牙香占和美香占2号的成活率分别为13.33%、12.67%和16.00%。桂香占(4.33%)、中香1号(1.33%)在高温处理后的成活率最低,表明两者的耐高温能力均较差。【结论】8个品种耐热性从强到弱依次为巴斯马蒂、玉香油占、湘晚籼13、农香18、象牙香占、美香占2号、桂香占和中香1号。

Morphophysiological Responses of Different Scented Rice Varieties to High Temperature at Seedling Stage

【Objective】The purpose of this research is to study the morphophysiological responses of different scented rice varieties to high temperature at seedling stage and to screen out heat-resistant varieties.【Method】With the super inbred fragrant rice Yuxiangyouzhan as control, a pot experiment was conducted in a light incubator, to reveal morphophysiological responses of seven inbred fragrant rice varieties (Basmati, Guixiangzhan, Nongxiang 18, Xiangwanxian 13, Xiangyaxiangzhan, Zhongxiang 1, Meixiangzhan 2) to high temperature stress. The morphophysiological indexes of the eight scented rice varieties were determined before and after high temperature treatment.【Result】Compared with Yuxiangyouzhan, the plant height, fresh weight, dry weight increased with a langer rate, the survival rate and POD activity in Basmati were higher under high temperature treatment. The malondialdehyde content was decreased by 33.39% for Basmati under high temperature treatment. It indicated that Basmati had higher tolerance to high temperature stress. The dry weight growth rate per plant of Xiangwanxian 13 under high temperature stress was equal to that of Yuxiangyouzhan with lower survival rate than Yuxiangyouzhan, and the change rate of intercellular CO2 concentration was lower after high temperature treatment, the SOD activity and the change rate of malondialdehyde content was the lowest among the eight varieties, indicating that its ability to withstand high temperature stress was slightly lower than that of Yuxiangyouzhan. The survival rates of Nongxiang18, Xiangyaxiangzhan and Meixiangzhan 2 were 13.33%, 12.67% and 16.00%, respectively. The survival rates of Guixiangzhan (4.33%) and Zhongxiang 1 (1.33%) under high temperature stress were the lowest among the eight varieties, indicating their weak high temperature tolerance.【Conclusion】In general, the heat resistance of the eight varieties from strong to weak was Basmati＞Yuxiangyouzhan＞Xiangwanxian 13＞Nongxiang 18＞Xiangyaxiangzhan＞Meixiangzhan＞Guixiangzhan＞Zhongxiang 1.