基于简化基因组技术的云南蓝果树群体遗传分析

极小种群野生植物云南蓝果树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。为有效保护其遗传资源，本研究通过二代测序技术，对其进行简化基因组测序，开发一批特异性高的单核苷酸多态性标记，分析现存群体的遗传结构和遗传多样性。经过遗传变异检测，本次研究中共获得SNP位点98 498个，通过样品最低测序深度>2，样品缺失率<0.5，次要基因型频率（MAF）>0.05筛选以后，得到有效SNP位点6 309个。基于过滤后的SNP，运用生物信息学分析方法，对云南蓝果树完成了群体的遗传分析，其中：系统进化树分析将云南蓝果树划分为3大类，研究分析了云南蓝果树各分类的私人等位基因数目（Private）、平均观测杂合度（H_o）、平均期望杂合度（H_e）、核苷酸多样性（π）和平均近交系数（F_IS）5个遗传多样性参数；群体结构和主成分分析进一步证明了，云南蓝果树现存植株之间亲缘关系较远，遗传多样性差异较大，具有很高的遗传资源保存价值。本研究结果将为基于遗传管理的云南蓝果树就地保护、遗传资源保存和种群重建等保护工程提供科学依据。

Population Genetic Analysis of Nyssa yunnanensis by Reduced-representation Sequencing Technique

Nyssa yunnananesis, a plant species with extremely small populations(PSESP), has become the flagship species in national and provincial conservation programs of PSESP. For effectively preserving the existing genetic resources, the recently developed technology restriction-site associated DNA sequencing(RAD-seq), which is based on next-generation sequencing(NGS), was used to develop a batch of highly specific single nucleotide polymorphism(SNP) markers and analyze genetic structure and genetic diversity of existing populations. After detection of genetic variation, a total of 98 498 SNPs were got. Under these conditions, the minimum sequencing depth of samples>2, sample missing rate < 0.5 and MAF > 0.05 screening from all 98 498 SNPs, 6 309 effective SNPs were obtained. Population genetics analysis of N.yunnananesis was analyzed using bioinformatic method with screening SNPs. Results demonstrated that the phylogenetic tree was divided into three clusters, in which the genetic diversity parameters, such as private, the nucleotide diversity(π), observed heterozygosity(H_o), expected heterozygosity(H_e) and inbreeding coefficient(F_IS) were elucidated. Population structure and PCA analysis further proved that N.yunnananesis had far relationships and quite different genetic diversity between the existing plants. Therefore, preserving genetic resources was of very high value. This study will give scientific evidences to protection engineering in particular the in-situ conservation, genetic resource preservation and population reestablishment with genetic management related methods and techniques.