小麦族中间鹅观草不同居群的形态多样性分析

小麦族（Triticeae）植物的野外调查、收集通常是以形态学为依据的。为了探讨小麦族植物在野外调查、收集的科学取样策略，本项研究以小麦族具有自花授粉习性的3个中间鹅观草（Roegneria sinica．vat．media Keng）居群、每个居群30个单株为材料，对11个形态学性状的多样性进行了分析。结果表明，3个居群的总遗传多样性指数为1．991，遗传多样性主要集中于居群内（91．76％），而居群间的遗传变异（8．24％）相对较小；不同取样梯度下的遗传多样性指数随单株取样数目的增加呈现增大趋势，但当取样数目达到18株时，遗传多样性指数达到最高值。上述结果说明，对于小麦族自花授粉植物野外调查、收集时，应以居群为单位，而且每一居群至少应调查、收集18个单株，才能代表居群的遗传多样性。以形态学为依据的取样策略的建立，对于指导野外调查、收集具有现实意义。

Diversity of Morphological Traits in Roegneria sinica .var. media Keng Populations of Triticeae

Field investigation and collecting of Triticeae wild species are generally based on morphological traits.In order to put forward the sampling strategy of Triticeae in the wild investigation and collecting,the diversity of eleven morphological traits were studied using three populations of Roegneria sinica .var. media Keng(self-pollination)with 30 plants chosen randomly for each population.The results showed that genetic diversity indexes of the three population was 1.9911.The genetic diversity within populations was higher(91.76%)than that of among populations(8.24%);and the diversity indexes in different sampling strategies increased along with the increasing of plant number.The diversity indexes were the highest when the sample number was 18.All together,the wild investigation and conservation of Triticeae plants in self-pollination should be based on population as a unit and the genetic diversity of populations could be represented with 18 individuals at least in each population. There was of practical significance for wild investigation and conservation to establish the guidance to sampling strategy based on morphology.