基于遗传管理的云南蓝果树种群恢复与重建研究

Nyssa yunnanensis is a critically endangered species with only two small populations in China, which has been listed in the national grade I protection and become the flagship species in national and provincial conservation programs of plant species with extremely small populations (PSESP). For effectively preserving genetic resources and reducing the risk of inbreeding depression, it is urgent to introduce genetic management related methods and techniques in conservation practices. Here, we use RAD-seq methods with the combination of SSR and SNP to establish an effective technique for paternity testing of N. yunnanensis. Phylogenetic relationships among natural and reestablished populations and their individuals are going to be unveiled, so as to provide reliable evidences for population restoration and reestablishment. The project contains: 1) analysis of genetic structures and genetic lineages of N. yunnanensis populations and establishment of its genetic profiles; 2) selection of hypervariable sites and development of paternity analysis and test techniques for N. yunnanensis; 3) evaluation of the effectiveness of reintroduced populations in in-situ conservation site and populations reestablished in quasi in-situ and ex-situ conservation sites based on genetic data, and optimization of population restoration and reestablishment plans. Research results give scientific evidences to protection engineering in particular the in-situ conservation, germplasm preservation and population reestablishment. At the same time, achievements in N. yunnanensis can be extended to other PSESPs through its demonstration effect, so that the conservation and management of wild plant species would be enhanced technically.

国家一级重点保护植物云南蓝果树（Nyssa yunnanensis）野外仅存2个种群，是国家和云南省实施极小种群野生植物保护工程的代表性物种。为有效保存遗传资源，降低近交衰退风险，急需在保护实践中引入遗传管理的技术方法。本项目拟采用二代测序技术，将SSR和SNP相结合，分析云南蓝果树天然、人工种群及其内部植株间的亲缘关系和遗传特征，为种群恢复和异地重建提供依据。具体内容包括：（1）分析天然和早期回归种群的遗传结构和遗传谱系，建立遗传档案；（2）筛选高变位点，建立高效准确的亲本分析和遗传鉴定技术；（3）根据遗传数据评价回归引种、近地和迁地保护种群，优化种群恢复重建方案。研究成果将为云南蓝果树的就地保护、种质保存、种群重建等保护工程提供科学依据，同时为其他极小种群野生植物的拯救保护提供示范，带动野生植物保护管理水平的提升。

云南蓝果树天然更新困难，物种濒临灭绝，是国家I级重点保护的野生植物和IUCN极度濒危种，也是国家和云南省实施极小种群野生植物保护工程的代表性物种。为有效保存遗传资源，降低近交衰退风险，急需在保护实践中引入遗传管理的技术方法。本项目通过二代测序技术，对其进行简化基因组测序，开发了一批特异性高的单核苷酸多态性标记，分析了现存群体的遗传结构和遗传多样性。具体内容包括：（1）分析了云南蓝果树天然种群和早期回归种群的遗传结构和遗传谱系，用 SNP 位点刻画其遗传特征，为每个成株建立了详细的遗传档案，构建了云南蓝果树的遗传谱系。（2）筛选了分辨率最高的遗传变异位点，建立了云南蓝果树的亲子鉴定技术，并选择了1个人工种群进行实际测试，最后优化并集成云南蓝果树亲子鉴定技术体系。（3）应用遗传谱系和亲子鉴定技术，检测、评价近地和迁地种群的保护有效性，提出重建种群的改造或建设方案。研究成果将为云南蓝果树的就地保护、种质保存、种群重建等保护工程提供科学依据，同时为其他极小种群野生植物的拯救保护提供示范，带动野生植物保护管理水平的提升。