基于SSR标记与化学成分构建十堰地区天师栗核心种质库＊

目的 利用筛选出十堰的天师栗中高多态性SSR位点评价天师栗种质资源的遗传多样性，结合有效药用成分含量，构建十堰地区天师栗核心种质库。方法 收集十堰地区114份天师栗种质资源，以七叶树基因组为参考，采用荧光毛细管电泳筛选出高多态性SSR位点，对天师栗种质资源进行遗传多样性分析。利用HPLC测定不同种质干燥娑罗子中七叶皂苷的含量。采用最小距离逐步聚类取样策略（LDSS），根据遗传多样性保留程度初步筛选出核心种质，并对该核心种质与原始种质的遗传多样性参数进行T检验，选择与原种质差异不显著的核心种质为最佳核心种质。结果 筛选出13对高多态性SSR分子标记，遗传多样性评价结果表明十堰地区天师栗种质资源遗传多样性较高，遗传分化较小，存在着较大的基因流，114份种质资源未分为不同的亚群，周家坝和辽叶居群间具有较近的遗传亲缘关系，且周家坝居群娑罗子中的七叶皂苷A及七叶皂苷B含量普遍较高。最终筛选出的核心种质共23份，占总种质资源的20.17%，其中周家坝12份样本、辽叶6份样本、普龄5份样本。结论 将SSR分子标记与主要有效药用成分结合，采用LDSS取样策略构建十堰地区天师栗种质资源核心种质库的方法具有可行性，能够有效的保存与管理天师栗种质资源，也为当地天师栗品种改良、新品种选育研究等提供了研究基础。

Construction of Aesculus wilsonii Core Germplasm Library in Shiyan Area Based on ISSR Markers and Chemical Constituents

Objective To construct the Core Germplasm Bank of A. wilsonii in Shiyan, by evaluating the genetic diversity of germplasm resources, screening high polymorphic SSR loci in A. wilsonii in Shiyan, and combined with the content of medicinal ingredients.Methods 114 A.wilsonii germplasm resources were collected, and SSR loci with high polymorphism were screened by fluorescence capillary electrophoresis based on the genome of A. chinensis to analyze the genetic diversity of A. wilsonii germplasm resources. HPLC was used to determine the contents of Aescines in different germplasm of A. wilsonii. The least distance stepwise sampling method (LDSS) was used to select the core germplasm according to the degree of genetic diversity retention, and T test was performed on the genetic diversity parameters between the core germplasm and the original germplasm. The core germplasm which had no significant difference from the original germplasm was selected as the best core germplasm.Results 13 pairs of highly polymorphic SSR markers were screened out. The genetic diversity evaluation results showed that the germplasm resources of A. wilsonii in Shiyan area had low genetic diversity, low genetic differentiation and large gene flow. The genetic differentiation was small and there was a large gene flow. The 114 germplasm resources were not divided into different subgroups. There was close genetic relationship between Zhoujiaba population and Liaoye population. Moreover, the contents of Aescin A and Aescin B were generally higher in seeds of A. wilsonii in Zhoujiaba population. A total of 23 core germplasm resources were screened out, accounting for 20.17% of the total germplasm resources, including 12 samples from Zhoujiaba, 6 samples from Liaoye and 5 samples from Puling.Conclusion It is feasible to combine SSR molecular markers with main effective medicinal ingredients and adopt LDSS sampling strategy to construct the core germplasm library of A. wilsonii germplasm resources in Shiyan area. The core collection will contribute to preserving and managing the wild germplasm resources of A. wilsonii and also provide the research foundation for the improvement and breeding of new varieties of A.wilsonii.