中文摘要：

以高山灌木鲜卑花为研究材料,收集其在中国全部分布区域内的13个居群共139个个体,以查尔酮合酶基因（CHS）的内含子区域为分子标记,探讨鲜卑花的种群动态历史、遗传分化的时间与成因。在鲜卑花中CHS共鉴定了29种单倍型,单倍型多样性和核苷酸多样性分别为0.9248和0.007 545,遗传变异大;贝叶斯分析说明鲜卑花种内遗传分化的时间始于4.37 Ma左右。中性检验与歧点分布分析一致表明鲜卑花在近期经历了明显的居群扩张,估算的扩张时间在55.8 ka左右。研究结果表明鲜卑花在末次冰期间冰阶时期从冰期避难所向外经历了明显的居群扩张;而青藏高原的整体隆升导致的环境剧变,加剧了鲜卑花居群间的遗传分化。

英文摘要：

The demography history and genetic divergence of alpine shrub Sibiraea laevigata were studied with13 populations（139 individuals） collected in the whole distribution area in China,using the intron of chalcone sythase（CHS） as molecular marker. A total of 29 haplotypes were identified in S. laevigata,indicating high haplotype diversity and nucleotide diversity which were 0. 924 8 and 0. 007 545,respectively. Bayesian calculation illustrated the genetic divergence in S. laevigata began at around 4. 37 Ma,proved that the uplift of Qinghai-Tibetan Plateau triggered the genetic divergence. Neutrality test and mismatch distribution analysis consistently indicated the populations of S. laevigata had experienced recent population expansion at about 55. 8 ka.