Abstract: The agronomic traits and biochemical characteristic of 16 hybrid and traditional rice varieties popularized in Hunan Province of China, were investigated under different submergence stresses at the tillering stage. The submergence tolerance of hybrid rice, revealed by the relative injury rate of leaf, was significantly stronger than those of traditional rice. The plant height of hybrid and traditional rice increased firstly and then decreased with the increase of submergence day, and the highest plant height of hybrid rice appeared on the 4 th day after submergence and on the 2 nd day in the traditional rice. The delay of heading increased with the duration of submergence, but the delay scopes of hybrid rice were less than those of traditional rice. The effective panicle number per plant, grain number per panicle, 1000-grain weight and yield per plant decreased with the increasing days of submergence and the decreasing ranges in hybrid rice were less than those in traditional rice. When the submergence day increased, the increased range of relative conductivity of hybrid rice was less compared with traditional rice. The content of malondialdehyde increased stably in hybrid rice, but increased at first and then dropped dramatically in traditional rice. The increase of proline content in hybrid rice was more than that in traditional rice. All the results showed that the submergence tolerance ability of hybrid rice is superior to traditional rice.

Key words: hybrid rice, traditional rice, submergence stress, agronomic traits, biochemical characteristics

摘要： 在分蘖期对目前湖南省普遍栽培的16个杂交稻和常规稻品种进行不同淹涝强度处理，测定了淹涝胁迫处理对杂交稻和常规稻的农艺性状、相对电导率、丙二醛和脯氨酸含量的影响。结果表明： 1）叶片相对受害率的高低表明杂交稻的耐淹涝能力明显强于常规稻。2）随着淹涝天数的增加，杂交稻和常规稻的株高都呈现出低高低变化规律，杂交稻出现最高株高的天数在处理4 d后，常规稻在处理2 d后。 3）随着淹涝天数的增加，杂交稻和常规稻的始穗期推迟的天数都增加，杂交稻始穗期推迟的天数幅度小于常规稻。 4）随着淹涝天数的增加，有效穗、实粒数、千粒重、单株产量都降低，杂交稻下降的幅度小于常规稻。 5）随着淹涝天数的增加，杂交稻相对电导率上升的幅度小于常规稻；在杂交稻中，丙二醛含量逐步上升，常规稻表现为先升高后急剧降低的变化趋势；杂交稻脯氨酸含量上升的趋势大于常规稻。 杂交稻耐淹涝胁迫的能力强于常规稻。

关键词: 杂交稻, 常规稻, 淹涝胁迫, 农艺性状, 生化特性