贺兰山丁香自然居群克隆生长格局及遗传多样性的ISSR分析

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(N_C)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(G_ST=0.320),表明自然居群间基因交流有限.

Clonal Structure and Genetic Diversity of Natural Syringa pinnatifolia var. alanshanica Assessed by ISSR

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 (N_C) 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 (G_ST) was 0.320,indicating less differentiation among populations than within populations.