中文摘要：

将野外观测与室内实验相结合,研究不同贮藏条件对大赖草种子萌发的影响。结果表明：室内干藏与野外埋藏于地表的种子随贮藏时间的延长,种子萌发率呈现缓慢升高后逐渐降低的趋势,说明大赖草种子存在着后熟现象;埋藏5 cm深度的种子,埋藏2、7、8个月时,种子自然萌发率分别为5.15%、7.52%和94%,剩余种子在室内条件下萌发率大于95%。而埋藏于原生境的种子埋藏2个月无萌发现象,埋藏8个月自然萌发率为90%;说明大赖草的种子在土壤中属于瞬间种子库;黑暗有利于大赖草种子的萌发。不同贮藏条件下大赖草种子的含水量表现为：埋藏5 cm深度〉埋藏于地表〉室内干藏,大赖草种子萌发的最低含水量为19.5%。在自然生境中,野外埋藏的种子被动物搬运的占12%～90%,平均达44.5%,致使土壤中种子数量锐减。因此,大赖草种子在土壤种子库中数量匮乏;自然生境中干旱少雨、水分缺少,导致种子萌发后易＂闪苗＂。这些因素是大赖草有性繁殖更新率低的主要原因。

英文摘要：

In this paper, the effects of different storage conditions on the germination of Leymus racemosus seeds were studied manipulatively both in field and laboratory. The results showed that the seed germination was in- creased initially and then decreased slowly as the increase of dry storage time and the buried time in topsoil, which revealed that there was an after-ripening in this species. The natural germination rates of the seeds buried in 5-cm depth in topsoil for 2, 7 and 8 months were 5.15%, 7.52% and 94% respectively. The percentage of un-germina- ted seeds under natural conditions could be 〉 95% in laboratory. There was no germination after the seeds were buried in natural habitat for 2 months, and the germination rate was as high as 90% after the seeds were buried for 8 months; thus, it could be considered that the seeds in soil formed a transient seed bank. Germination rate of L. racemosus seeds was increased under darkness. Moisture content of seeds under different storage conditions was in an order of seeds buried at 5-cm depth 〉 seeds buried in topsoil 〉 dry storage in laboratory, and the minimum moisture content of seeds was 19.5%. In the natural habitat, the proportion of seeds removed by animals varied in a range of 12% -90% （44.5% in average）, as a result, the number of seeds in soil was sharply decreased. Seedlings of L. racemosus in the natural habitat may die in short period under drought, so the renewal of sexual reproduction of L. racemosus was low in the natural habitat.