| 【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. |
