苦玄参遗传差异分析及优良种质特征SSR分子标记筛选研究

Picria fel-tearrae Lour., as one of the medicinal plants that being collected by the Chinese Pharmacopoeia edited in 2010, was one of the ten medicinal plants that were major supported by Guang Xi in the 12th Five-Year period. The quality of the Picria fel-tearrae medicinal material that mainly comes from artificial production at present was diversity for its differences in germplasm sources, and that made it difficult for herb doctor and traditional Chinese medicine enterprises to determine the dosage. The quality of the Chinese medicinal materials were determined by the composition and content of chemical components that were mainly affected by the germplasm and producing area. Germplasm was the internal and main cause that made it was one of the important scientific problems to select high-quality germplasm. Based on the magnetic beads enriched method, SSR molecular marker primers were developed and SSR molecular markers that was associated with synthesis of piefeltarraeninIA of the Picria fel-tearrae population and single plant from different producing areas were established using the developed primer in this research. The characteristic SSR molecular marker of the high quality Picria fel-tearrae would be established by analysis the difference of the SSR molecular marker of the Picria fel-tearrae population and single plant that was diversity on the content and proportion of active substance. The result could finally guide the elite germplasm identify and selection, fine seeds selection, genetic improvement and genetic diversity analysis for the artificial cultivation of Picria fel-tearrae .

苦玄参是2010版中国药典收录的药用植物，是广西十二五期间重点扶持的 十大中药材之一。目前苦玄参药材主要来源于人工种植，由于其野生种质来源差异较大，药材质量良莠不齐，给中医用药及企业药材用量规范带来困难。药材质量主要与其化学成分的组成和含量有关，而化学成分组成和含量主要受药材的种质特性及生长环境的影响。种质是内因，优良种质的鉴定和筛选，是中药材生产需要解决的关键科学问题之一。项目以不同地理来源的苦玄参居群及形态差异显著的单株为研究对象，拟采用磁珠富集法开发与苦玄参苷合成相关的SSR分子标记引物，并利用开发的引物构建不同居群及单株的SSR分子标记。通过分析不同地理居群及单株的遗传差异，筛选优势居群及优质苦玄参特征SSR分子标记图谱，最终确定苦玄参优势地理居群及建立优质苦玄参种质的鉴别方法。其结果将为人工种植苦玄参药材的优良种质鉴别和筛选、良种选育、遗传改良及遗传多样性分析提供科学依据。

本项目以来源于广西和云南两省18县的苦玄参居群，及基于表型性状差异在广西苦玄参主产区梧州和龙州筛选出的苦玄参株系为实验材料，进行了以下研究:1.以苦玄参苷IA和IB含量为评价指标，筛选含量较高的优良种质；2.采用SSR、SNP分子标记技术，研究不同来源苦玄参遗传多样性及亲缘关系；3.基于苦玄参苷含量与SSR、SNP分子标记的相关性，构建苦玄参优良种质特征DNA指纹图谱。通过研究，明确了不同苦玄参种质间的遗传结构和亲缘关系；筛选优良苦玄参株系5株，并已进行扩繁，有望通过繁育，培育优良新品种1~2个；挖掘出与苦玄参苷含量相关联的分子标记和相关位点，并对其功能进行了注释，同时建立了苦玄参优良种质特征SSR指纹图谱。该研究结果可为苦玄参优良种质筛选和培育提供方法和依据。项目基本完成了任务书规定的研究内容及预期目标。