华南稻区不同水稻品种耐淹出苗能力及秧苗素质比较

Comparison of Seedling Emergence Capacity and Seedling Quality of Different Rice Varieties with Submergence Tolerance in South China

【目的】评价不同水稻品种淹水直播方式下的耐淹出苗能力以及淹后的秧苗素质。【方法】以前期初筛获得的11份耐淹性水稻种质资源为材料,进行大田淹水直播(淹水5 cm)处理,以湿润直播作为对照,研究淹水直播条件下的出苗率、秧苗期的单株分蘖数、株高、茎高、叶龄、根冠比等主要秧苗素质,比较分析了不同水稻品种对淹水直播的出苗率以及农艺性状的响应差异。以淹水直播和湿润直播条件下各农艺性状为基础数据,对秧苗期的秧苗素质进行比较。【结果】淹水直播对出苗率和秧苗期的根冠比影响较大,出苗率可作为评价淹水直播条件下耐淹出苗能力的重要指标。以出苗率作聚类分析评价各品种的耐淹出苗能力,筛选出吊黎望、朝安龙眼两个耐淹出苗能力强的材料。淹水直播25 d后,各品种秧苗期的单株分蘖数、叶龄减少,根冠比增加,株高和茎高则表现为耐淹出苗能力强的品种呈降低趋势,而耐淹出苗能力弱的品种则相反。【结论】淹水直播显著影响直播稻的出苗率,影响水稻秧苗期的农艺性状,其中对秧苗期根冠比的影响最大。

【Objective】The study was carried out to evaluate the seedling emergence capacity and seedling quality of different rice varieties with submergence tolerance under submerged direct seeding mode.【Method】In this study,11 rice germplasm resources with submergence tolerance obtained from preliminary screening were used as materials for field submergence direct seeding(submergence depth:5 cm) and wet direct seeding was set as control.Main seedling qualities including emergence rate,tiller number per plant,plant height,stem height,leaf age and root-shoot ratio were studied under submerged direct seeding.The differences in responses of different rice varieties to the emergence rates and agronomic traits of submerged direct seeding were compared and analyzed.Based on the agronomic traits of submerged direct seeding and wet direct seeding,the seedling quality at seedling stage was compared.【Result】Submerged direct seeding had great influence on emergence rate and root-shoot ratio at seedling stage,and emergence rate could be used as an important index to evaluate the submergence tolerance under submerged direct seeding.The emergence rate was used as cluster analysis to evaluate the submergence tolerance of various varieties,and two materials with stronger submergence tolerance were selected,namely,Diaoliwang and Chaoanlongyan.After 25 days of submerged direct seeding,the tiller number per plant and leaf age of each variety at seedling stage decreased,while the root-shoot ratio increased.The plant height and stem height showed a decreased trend for the varieties with strong submergence tolerance,whereas the varieties with weak submergence tolerance showed a reversed trend.【Conclusion】Under submerged direct seeding,the emergence rates and the agronomic traits were influenced significantly at seedling stage,especially the root-shoot ratio was influenced most at seedling stage.