College of Nature Conservation, Beijing Forestry University, Beijing, China.
Fangcheng Golden Camellia National Nature Reserve Management Center, Fangchenggang, China.
PLoS One. 2024 Sep 4;19(9):e0309283. doi: 10.1371/journal.pone.0309283. eCollection 2024.
Annamocarya sinensis (Dode) Leroy, a relict plant from the Tertiary period, is a member of Annamocarya genus in the Juglandaceae family. Despite its wide distribution in Guangxi Province, the habitats of this species had become fragmented and isolated, causing it facing deterioration. For protecting this endangered species, it is crucial to understand its status in the wild and genetic diversity. In this study, 216 A. sinensis accessions from 18 populations in Guangxi were examined using Start Codon Target Polymorphism (SCoT) markers for PCR amplification, genetic diversity, and population structure analysis. Out of the 20 SCoT primers used, 222 sites were amplified, with 185 being polymorphic (PPB of 83.33%). Polymorphic information content values ranged from 0.4380 to 0.4999, Nei's genetic diversity index ranging from 0.1573 to 0.2503, and Shannon diversity index ranged from 0.1583 to 0.3812. Through AMOVA analysis, the total genetic diversity and genetic diversity within populations was calculated out as 0.3271 and 0.1542 respectively, the genetic differentiation coefficient between populations was 0.5286, with a gene flow 0.4458. Cluster analysis categorized A. sinensis germplasm into three groups, while population structure analysis divided all accessions into three ancestral sources with 19.91% showing mixed ancestral origins. No significant correlation was observed between genetic and geographical distance on the Mentel test (r = 0.07348, p = 0.7468). Overall, A. sinensis displays a relatively rich genetic diversity at the species level, albeit with a fairly uniform genetic background and high genetic differentiation. This study provides a crucial basis for the conservation and innovative use of A. sinensis germplasm resources.
中国榉树（Dode）Leroy 是一种第三纪遗留下来的植物，属于胡桃科榉树属。尽管它在广西广泛分布，但该物种的栖息地已变得破碎和孤立，导致其面临恶化。为了保护这一濒危物种，了解其在野外的状况和遗传多样性至关重要。在这项研究中，使用起始密码子目标多态性（SCoT）标记对来自广西 18 个种群的 216 个中国榉树个体进行了 PCR 扩增、遗传多样性和种群结构分析。在使用的 20 个 SCoT 引物中，扩增出了 222 个位点，其中 185 个为多态性（PPB 为 83.33%）。多态信息含量值范围为 0.4380 至 0.4999，Nei 的遗传多样性指数范围为 0.1573 至 0.2503，Shannon 多样性指数范围为 0.1583 至 0.3812。通过 AMOVA 分析，计算出总遗传多样性和种群内遗传多样性分别为 0.3271 和 0.1542，种群间遗传分化系数为 0.5286，基因流为 0.4458。聚类分析将中国榉树种质分为三组，而种群结构分析将所有个体分为三个祖先来源，其中 19.91%表现出混合祖先起源。在 Mentel 检验中，遗传距离与地理距离之间没有观察到显著相关性（r = 0.07348，p = 0.7468）。总体而言，中国榉树在物种水平上表现出相对丰富的遗传多样性，但遗传背景较为均匀，遗传分化较高。本研究为中国榉树种质资源的保护和创新利用提供了重要基础。
