濒危药用植物黄芪种质资源的遗传评价与核心种质库的构建

Astragalus membranaceus(Astragali Radix) is one of the common medicinal herbs in China. However, its wild resources are on the verge of extinction and cultivated resources are mixed. Thus, it is imperative to establish a proposal for the effective conservation of germplasm resources. The project aims to reveal the reveal the level of genetic diversity, the degree of genetic differentiation and the phylogeographic pattern in both natural and cultivated populations of Astragalus membranaceus through the combination of the molecular phylogeography theory and nuclear SSR and sequencing analysis of non-coding region of chloroplast genome.Therefore， the core ermplasm will be built and the priority protection unit will be identified. We will select samples from the core germplasm for field cultivation experiment and determine the main content of Astragalus membranaceus, which are the index components according to "Chinese Pharmacopoeia", and finally fliter out the high content plants. The project will provide a theoretical basis for protecting and breeding fine germplasm and make strategies for the construction of core germplasm in Astragalus membranaceus. Simultaneously, it will not only rich the phylogeography theory, but also provide a scientific reference to the historical change of the origin of medicinal plants.

黄芪（Radix Astragali）是我国大宗常用药材之一。但其野生资源濒临枯竭，栽培资源种质混杂，对其种质资源进行有效保育已刻不容缓。本研究拟采用核基因组SSR和叶绿体基因组DNA非编码区测序分析，结合分子谱系地理学理论，揭示黄芪自然居群和栽培居群的遗传多样性水平、遗传分化程度和谱系地理格局，初步构建核心种质，确定优先保护单元。选择核心种质中样本进行田间栽培试验，并利用HPLC测定《中国药典》所规定的指标成分黄芪甲苷和毛蕊异黄酮葡萄糖苷含量，筛选出高含量等优良植株。研究结果可以为黄芪优异种质保护、选育，以及核心种质构建策略的制定提供理论依据。同时可丰富分子谱系地理学理论，为药用植物道地性产地变迁历史研究提供科学依据。

本项目着眼于我国中药产业的快速发展，选择我国重要的大宗常用药材之一黄芪（Radix Astragali）进行了居群取样研究，进行其遗传多样性分析及构建其分子标记核心种质。本研究首先测定了两种黄芪不同变异类型性状指标，并以此分析了两种黄芪的表型多样性，为表型核心种质提供了物质基础。采用了ISSR分子标记进行了居群遗传学的分析，蒙古黄芪的遗传多样性水平高于膜荚黄芪，对此探讨了两物种差异的原因。采用了核基因组 ITS及叶绿体基因组 DNA非编码区域进行了 psbA-trnH、trnL-trnF测序，通过 Contig、DNAMan 软件拼接比对及 Mage 5聚类等分析，有望从不同层面上分析其遗传多样性，寻找出特有基因型或单倍型植株，并根据黄芪EST-SSR特性，筛选出10对SSR引物，将继续进行遗传多样性的评价和分子标记核心种质的构建。结合不同产地膜荚黄芪和蒙古黄芪主要有效成分进行分析得出，蒙古黄芪总黄酮、毛蕊异黄酮、芦丁、芒柄花素等成分多为山西浑源地区含量最高，膜荚黄芪总黄酮、毛蕊异黄酮苷、芒柄花苷、芦丁为黑龙江和辽宁产地为最高。此结果为黄芪的核心种质构建补充了主要有效成分的划分。