中文摘要：

对披碱草幼穗分化和发育过程进行解剖观察,结果表明披碱草幼穗经历了初生期、伸长期、结节期、小穗突起期、颖片突起期、小花突起期、雌雄蕊形成期、抽穗期共8个不间断的分化时期。在披碱草分蘖期,幼穗分化经历了初生期、伸长期和结节期3个时期;在拔节期,幼穗分化经历了小穗突起期和颖片突起期2个时期;小花突起期和雌雄蕊形成期集中于孕穗期,幼穗分化结束于抽穗期。分化过程中,穗中上部的小穗先发育,后向上下两个方向发育,穗基部的小穗发育较晚;小穗基部的小花先发育,然后由基部向上逐渐发育。

英文摘要：

The differentiation and development of young spikes of Elymus dahuricus Turcz.were dissected and observed.The results showed that the young spike differentiation of Elymus dahuricus Turcz. was a consecutive process,which can be divided into eight stages：vegetative stage,elongation stage,single ridge stage,spike protuberances stage,glume protuberances stage,floret differentiation stage,gynoecium and stamen formation stages and heading stage.Vegetative stage,elongation stage and single ridge stage of the young spike differentiation occurred in tillering stage.Spike protuberances stage and glume protuberances stage occurred in elongation stage.Floret differentiation stage,gynoecium and stamen formation stages occurred in booting stage.The young spike differentiation was ended in heading stage.During the process of differentiation,the spikelets in the middle and upper parts of spike developed first,and then developed gradually upward and downward,the spikelets in base part of the spike developed later, the florets in base part of spikelets developed first,then developed from base to top gradually.