Li Lianxing, Ou Wenli, Wang Yuchang, Peng Jingyu, Wang Dawei, Xu Shuo
Key Laboratory for Forest Resource Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming, Yunnan 650224, China.
Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100083, China.
Gene. 2022 Jun 30;829:146498. doi: 10.1016/j.gene.2022.146498. Epub 2022 Apr 18.
Docynia delavayi (Franch.) Schneid. (D. delavayi), is a wild fruit tree which combines edible, medicinal, ecological and ornamental uses. In this study, ancient and common populations of D. delavayi were examined for genetic diversity and structure using SSR markers. As a result, a total of 136 alleles were detected at 18 SSR loci, with the mean of 7.56 alleles. The value of Na, Ne, I, He and Nm of the ancient populations were lower than those of the common populations except for Ho and Fst. It indicates that the genetic diversity of the common populations is higher than that in ancient populations. The genetic differences between ancient populations were slightly greater than those between common populations, which demonstrated less gene flow between ancient populations. According to the analysis of molecular variance (AMOVA), the genetic variation within the common population was greater than that in the ancient population, indicating that there was a higher genetic diversity within the common population. Also, the clustering heatmap results are partially consistent with the principal coordinate analysis (PCoA) results. Moreover, the mantel test showed an extremely significant correlation between genetic and geography distance (r = 0.214, p < 0.0001). Based on this work, we proposed strategies for protecting, which offers a theoretical basis for their effective utilization and conservation of D. delavayi ancient tree resources.
滇苹果（Docynia delavayi (Franch.) Schneid.）是一种集食用、药用、生态及观赏用途于一身的野生果树。在本研究中，利用SSR标记对滇苹果的古老群体和普通群体进行了遗传多样性和结构分析。结果显示，在18个SSR位点共检测到136个等位基因，平均每个位点有7.56个等位基因。除观察杂合度（Ho）和固定指数（Fst）外，古老群体的等位基因数（Na）、有效等位基因数（Ne）、信息指数（I）、期望杂合度（He）和基因流（Nm）值均低于普通群体。这表明普通群体的遗传多样性高于古老群体。古老群体之间的遗传差异略大于普通群体之间的遗传差异，这表明古老群体之间的基因流较少。根据分子方差分析（AMOVA），普通群体内的遗传变异大于古老群体内的遗传变异，表明普通群体内具有更高的遗传多样性。此外，聚类热图结果与主坐标分析（PCoA）结果部分一致。而且，mantel检验显示遗传距离与地理距离之间存在极显著相关性（r = 0.214，p < 0.0001）。基于此研究成果，我们提出了保护策略，为滇苹果古树资源的有效利用和保护提供了理论依据。
