Clonal diversity,growth structure,and genetic diversity of 8 natural Syringa pinnatifolia var. alanshanica populations were assessed by ISSR molecular markers. Results showed that 16 ramets of 3 individual genets shared the same genotype,whereas 136 genotypes were differentiated among the other 239 samples from 7 populations. Clonal diversity revealed that S. pinnatifolia var. alanshanica was a phalanx clonal species and each population was composed of several clones. Most genets contained one ramet and the highest quantity of one genet consisted of 8 ramets. A relatively high clonal diversity of genotype Simpson' s index (D= 0. 994) and distributional uniformity of genotype Fager' s index (E=0. 985) was detected. Individuals per genotype (Nc) and mean genotype proportion (PD) were 1. 729 and 0. 578,respectively, at the species level. In addition,high genetic diversity was detected at both population and species level. The coefficient gene differentiation ( GST) was 0. 320,indicating less differentiation among populations than within populations.%运用ISSR分子标记技术,通过制定挖掘采样、“+”形采样及“垂直”采样3种采样方案,对贺兰山丁香(Syringa pinnatifolia var.alanshanica)不同居群的克隆多样性、克隆生长格局及其遗传多样性进行了分析.克隆多样性分析表明:挖掘采样方式采到的3个克隆系内,各自所包含的单株间具有完全相同的基因型；“垂直”采样及“+”形采样的7个居群、239个样品表现出136个不同的基因型或克隆,显示贺兰山丁香具有较高的克隆多样性(D=0.994)及基因型分布均匀性(E=0.985).克隆生长空间格局分析表明,贺兰山丁香为密集型克隆植物.每个居群都由多克隆组成,克隆生长只发生在同一丛内,多数基株只含有1个分株,最多可达8个.物种水平上的平均克隆大小(Nc)和平均基因型比例(PD)分别为1.757和0.569.对贺兰山丁香遗传多样性分析的结果显示,在居群水平和物种水平上都保持着较高的遗传多样性,其遗传变异主要存在于居群内；但居群间分化程度较低(GST=0.320),表明自然居群间基因交流有限.
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