新疆产药用植物黑果枸杞遗传多样性的ISSR分析

黑果枸杞（Lycium ruthenicum）隶属于茄科枸杞属，为重要的药用植物，主要分布于中国的西北部。目前该种野生”资源逐渐减少，开展对其居群遗传学研究有利于黑果枸杞野生种质资源的保护和可持续利用。采用ISSR分子标记对新疆南部黑果枸杞6个自然居群及甘肃2个自然居群共115个样品进行了DNA多态性分析。从60个随机引物中筛选出7个有效引物，共产生64条DNA片段，其中50条为多态性条带，多态位点百分率（PPL）为78．1％。相比较而言，黑果枸杞在物种水平上具有较高的遗传多样性，Nei基因多样性（H）和Shannon多样性指数（Ⅰ）分别为0．29和0．43。对黑果枸杞8个居群的AMOVA分析结果表明，其遗传变异主要存在于居群内（77．0％），而居群间的遗传分化较小（23％，Fsr=0．23）。黑果枸杞各居群间的遗传距离在0．0570—0．1913之间变化。居群间的聚类及Mantel检验（r=0．3602，P=0．910）均表明新疆黑果枸杞居群地理距离与遗传距离之间的相关性不明显；黑果枸杞个体间UPGMA聚类结果表明，同一居群的个体不能完全聚在一起，来自新疆和甘肃两区域的黑果枸杞材料也不能完全分开。探讨了可能造成上述居群遗传结构模式的主要因素，同时提出了今后对新疆南部黑果枸杞保护工作中需进一步解决的问题。

ISSR Analysis on Genetic Diversity of Medically Important Lycium ruthenicum Murr. in Xinjiang

Lycium ruthenicum （Solanaceae） is an important medicinal plant mainly distributed in Northwestern China. In recent years, however, the distribution range of this species has been reduced greatly due to human overexploitation and deterioration of its habitat. Studying the population genetics of this species is essential for the conservation and sustainable utilization of the plant germplasm resource. In this study, we used seven ISSR markers to measure genetic diversity of 115 individuals from eight natural populations of L, ruthenicum in Xinjiang （six populations） and Gansu （two populations）. A total of 64 DNA fragments were scored, and 78. 1% of polymorphic loci （PPL） found. High level of genetic diversity was detected in L. ruthenicum （ H = 0. 29; Ⅰ= 0. 43）. AMOVA analysis indicated that most variance （77. 0%） resided within populations, with only a small proportion of total variation residing between populations （23%, FsT=0. 23）. Results of the Mantel test （r=0. 3602, p=0. 910） and UPGMA cluster of the Xinjiang populations indicated that there was no significant relationship between geographical distance and genetic distance. UPGMA cluster of all sampled individuals showed that individuals from each population did not cluster together. The probable causes that have contributed to the current pattern of genetic structure were discussed and suggestions on future protection of the L. ruthenicum from southern Xiniianq were also .qiven.