Seed submergence tolerance of four annual species growing in the water-level-fluctuation zone of Three Gorges Reservoir, China, and effects of long-term submergence on their seed germination
Seed submergence tolerance of four annual species growing in the water-level-fluctuation zone of Three Gorges Reservoir, China, and effects of long-term submergence on their seed germination
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DOI：
10.3724/sp.j.1258.2011.00237
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发表时间：
2011-03-01
影响因子：
--
通讯作者：
Huang Wen-Jun
中科院分区：
文献类型：
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作者：
Shen Jian-Hong;Zeng Bo;Huang Wen-Jun
目的 考察我国三峡水库水位消落带中生长的四种常见一年生植物稗、苍耳、蓍草和蓼的种子在水位消落带变化中的淹没和萌发耐受性。方法将水位消落带划分为 根据吴淞高程标准划分为九个高程区。然后，我们将四种物种的种子播种在九个海拔区域后，在“蓄水-水衰退”循环中观察种子的耐淹性以及浸水对种子萌发的影响。种子萌发分为表面有沙粒和无沙粒的种子。 重要发现 4个物种的成熟种子（或果实）在浸水后仍保持活力。淹没结束后种子萌发起始时间和种子萌发持续时间均随海拔降低而逐渐缩短(p < 0.01),且169 m以下种子萌发起始时间显着缩短(p < 0.01)。
Aims Our objective was to examine seeds of Echinochloa crusgalli, Xanthium sibiricum, Aeschynomene indica and Polygonum hydropiper, four common annual species growing in the water-level-fluctuation zone of Three Gorges Reservoir in China, in regard to tolerance of submergence and germination in the changing environment of the zone.Methods We divided the water-level-fluctuation zone into nine elevational zones according to the Wusong Elevation criterion. We then observed seed submergence tolerance and the effects of submergence on seed germination in a "water impoundment-water recession" cycle after seeds of the four species were sown in the nine elevational zones. Seed germination was divided into seeds with and without sand sediment on surface.Important findings Ripe seeds (or fruits) of the four species kept their vitality after submergence. The starting time for seed germination after the end of submergence and seed germination duration both gradually decreased with decreasing elevation (p < 0.01), and the starting time for seed germination was significantly reduced below 169 m (p