华山新麦草居群取样策略的SSR分析

为了研究我国特有植物华山新麦草（Psath yrostachys huashanica Keng）的遗传多样性并获得更为科学、合理的结论，以分布于不同海拔高度黄埔峪（海拔500m）和大夫峪（海拔1218m）的2个华山新麦草居群为研究对象，每个居群分单株采集30株并以6、10、14、18、22、26和30株为单位，利用10对SSR引物对其遗传多样性进行分析。结果表明：（1）分布于较低海拔的黄埔峪居群的平均等住变异数（6．3）和遗传多样性指数（0．713）大于分布于较高海拔的大夫峪居群的等位变异数（5．1）和遗传多样性指数（0．662）；（2）随着分析单位个体数目从6株增加到30株，黄埔峪居群和大夫峪居群的等位变异数（42～63和43～51）和遗传多样性指数（0．643～0．713和0．618～0．662）均表现增大的趋势，但当分析单住的个体数目达到26株以上时，等位变异数和遗传多样性指数基本不再发生变化；（3）当分析单位个体数目为18株时，2个居群的等位变异数和遗传多样性指数分别包含了各自居群95％以上的遗传变异，建议在利用SSR技术进行华山新麦草居群遗传多样性研究中，以单个居群随机采集18株华山新麦草为最佳分析单位个体数目。

SSR Analysis on the Sampling Strategy of Psathyrostachys Huashanic Keng Population

To investigate the Genetic diversity of Chinese endemic grass species Psathyrostachys huashanica Keng effectively,two natural populations distributed in altitude of Huangpuyu(500 m) and Dafuyu(1 218 m) were evaluated by 10 pairs of simple sequence repeat(SSR) markers in 7 sample levels with different sample size.The results showed:(1)the average number of alleles(6.3)and genetic diversity index((0.713)) of low altitude population Huangpuyu were higher than those of high altitude population Dafuyu((5.1) and 0.662,respectively);(2) the number of alleles(42~63 and 43~51) and genetic diversity index(0.643~0.717 and 0.618~0.662) of Huangpuyu and Dafuyu populations increased along with the sampling size from 6 to 30 plants,and became relatively uniform when the sample size over 26;(3) As the sample size was 18,the number of alleles and genetic diversity index of 2 populations owned more than 95 percentage genetic variations of the total population,therefore,we suggested that 18 individuals could represent the whole population of Psathyrostachys huashanica Keng based on the genetic diversity of SSR.