Oryza sativa is a major food crop in Asia. In recent years, typhoons and sudden downpours have caused field flooding, which has resulted in serious harm to the production of rice. In this study, our data revealed that the plant heights of the five Japonica varieties increased during submergence. The elongation rates of TN14, KH139, and TK9 increased significantly during submergence. Chlorophyll contents of the five varieties significantly decreased after submergence and increased after recovery. Moreover, the chlorophyll content of KH139 was significantly higher than those of the other four varieties after recovery. The plant survival rates of the five varieties were higher than 50% after four-day submergence. After eight-day submergence, the survival rate of KH139 remained at 90%, which was the highest among the different varieties. The KH139 presented lower accumulation of hydrogen peroxide and the catalase activity than those of the other four varieties under submergence. The sucrose synthase 1 and alcohol dehydrogenase 1 were induced in KH139 under submergence. The results presented that different varieties of japonica rice have different flood tolerances, especially KH139 under submergence was superior to that of the other four varieties. These results can provide crucial information for future research on japonica rice under flooding stress.

中文翻译：

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淹水胁迫下不同粳稻品种的幼苗表现出不同的生理特性以调节植物的成活率。

稻 稻是亚洲主要的粮食作物。近年来，台风和倾盆大雨造成了田间洪水，严重危害了水稻的生产。在这项研究中，我们的数据显示五个粳稻的株高淹没期间品种增加。在浸没期间，TN14，KH139和TK9的伸长率显着增加。淹没后，五个品种的叶绿素含量显着下降，而恢复后则增加。而且，恢复后KH139的叶绿素含量明显高于其他四个品种。淹没四天后，这五个品种的植物成活率均高于50％。淹没8天后，KH139的存活率保持在90％，在不同品种中最高。在淹没状态下，KH139的过氧化氢积累和过氧化氢酶活性低于其他四个品种。的蔗糖合酶1和醇脱氢酶1浸没在KH139中被诱导。结果表明，不同品种的粳稻具有不同的耐旱性，其中淹水条件下的KH139优于其他四个品种。这些结果可为今后在淹水胁迫下粳稻的研究提供重要信息。