陕西唐棣遗传多样性和遗传分化的AFLP分析

采用扩增片段长度多态性分子标记技术对陕西省分布的6个野生唐棣居群的96个个体进行了遗传多样性分析, 以明确野生唐棣资源的亲缘关系，为唐棣资源的保护、良种选育和开发利用提供理论依据。结果显示：(1)从64对引物组合中筛选出8对扩增条带清晰、多态性高的引物组合，共扩增出277条清晰条带，其中多态性条带116条，多态性位点百分率为42.86%。(2)UPGMA聚类、主坐标分析(PCoA)和遗传结构分析结果相似，将6个陕西野生唐棣居群分成2大支，秦岭南北居群间遗传分化明显，且群体间存在一定基因流。(3)分子方差分析(AMOVA)结果显示遗传变异主要存在于居群内(63%)，居群间遗传变异为37%。Mantel检验表明陕西唐棣居群地理距离与遗传距离之间无明显相关性(r = 0.192，P = 0.220)。研究表明，AFLP分子标记可以准确、有效地用于唐棣遗传多样性分析；唐棣遗传变异主要来源于居群内，居群间的基因交流有限；陕西野生唐棣遗传多样性水平较低，但部分居群的遗传多样性较高。该研究结果可为野生唐棣资源的保护、良种选育和开发利用提供理论依据。

Genetic Diversity and Genetic Differentiation of Amelanchier sinica in Shaanxi Province as Revealed by AFLP

Amelanchier sinica has important ornamental, nutritional, and ecological value. Genetic diversity studies could lay a foundation for the protection and utilization of its resources. We analyzed the genetic diversity of 96 individuals from 6 natural populations in Shaanxi Province using amplified fragment length polymorphism (AFLP) markers, so as to clarify the genetic relationship of A. sinica and provide theoretical basis of the protection, breeding and utilization for A. sinica resources. The results showed: (1) eight primers with strong polymorphism were identified from 64 AFLP primers, generating a total of 277 bands, of which 116 (42.86%) showed polymorphism. (2) The results of UPGMA clustering, principal coordinate analysis (PCoA) and structure analysis indicated that the 6 wild populations of A. sinica were divided into two groups. (3) There was obvious genetic differentiation between north and south in the Qinling Mountains, and there was some gene flow among the populations. The results of molecular variance analysis (AMOVA) indicated that 37% of genetic variation is derived from among populations and that 63% is derived from within populations. The results of the Mantel test (r = 0.192, P = 0.220) of the wild populations of A. sinica in Shaanxi Province indicated that the correlation between geographical distance and genetic distance was not significant. The results showed that AFLP molecular markers could be used to analyze the genetic diversity of A. sinica accurately and effectively; more genetic variation in A. sinica existed within populations, while gene exchanged among populations was limited. The overall genetic diversity of A. sinica in Shaanxi Province was relatively low, while some populations had higher genetic diversity. These results provide a theoretical basis for the protection of wild germplasm resources, breeding of elite varieties and development and utilization of the resources of wild populations of A. sinica.