长江下游不同类型水稻分蘖期耐淹能力比较

Comparison on submergence tolerance of different type rice at tillering stage in lower reaches of Yangtze River

在分蘖期对长江下游稻作区主栽的9个水稻品种进行大田模拟没顶淹涝处理,研究淹涝胁迫对水稻植株农艺性状、生理指标和产量性状的影响,比较分析了常规粳稻、杂交籼稻和杂交粳稻对淹水胁迫环境适应性的差异.结果表明:淹水胁迫4 d后,水稻株高及顶部全展3片叶长均比对照有不同程度的增加,伸长程度为杂交粳稻>杂交籼稻>常规粳稻.杂交粳稻的茎蘖数、绿叶数和地上部干质量损失率分别为18.0%、41.4%、13.2%,显著小于常规粳稻;杂交籼稻则介于杂交粳稻和常规粳稻之间,且整株死亡率显著低于常规粳稻.常规粳稻叶片中丙二醛(MDA)含量比对照增加1.91μmol·g-1FM,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性明显降低;杂交粳稻和杂交籼稻MDA含量分别降低2.32和2.10μmol·g-1FM,SOD和CAT活性显著提高.不同类型品种的减产程度差异显著,常规粳稻的产量损失率达到38.5%,显著高于杂交粳稻和杂交籼稻,杂交粳稻产量损失率仅为4.1%.长江下游水稻分蘖期的耐淹涝能力为杂交粳稻强于杂交籼稻,常规粳稻的耐淹能力最低.

The agronomic traits,physiological characteristics and yield traits of 9 rice varieties popularized in lower reaches of Yangtze River were investigated under submergence stress at the tillering stage. The differences of environmental adaptability to submergence stress for conventional japonica rice,indica hybrid rice and hybrid japonica rice,were also analyzed and compared. The results showed that the stem and the upper three leaves under submergence stress were elongated compared with the control. And the elongation of the different varieties was shown as,hybrid japonica rice 〉 indica hybrid rice 〉 conventional japonica rice. As to the numbers of tillers and green leaves,and the aboveground dry mass,the reduction of indica hybrid rice was all between hybrid japonica rice and conventional japonica rice. The damage of hybrid japonica was the lightest. The content of MDA in the leaves of conventional japonica rice increased,while the activities of SOD and CAT decreased. However,the performances of hybrid japonica rice and indica hybrid rice were opposite with conventional japonica rice. The yield loss of conventional japonica rice was significantly higher than those of the other types of rice. These results suggested that the submergence tolerance ability of hybrid japonica rice is superior to indica hybrid rice,and the submergence tolerance ability of conventional japonica rice is the weakest.