Study on the Genetic Structure Based on Geographic Populations of the Endangered Tree Species: <i>Liriodendron chinense</i>

• Main Authors: Peng-Yan Zhou, Li-Xing Hui, Shu-Jing Huang, Zhou-Xian Ni, Fa-Xin Yu, Li-An Xu
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Forests
• Subjects: conservation biology; genetic diversity; genetic structure; <i>Liriodendron chinense</i>; phylogeography; species distribution pattern
• Online Access: https://www.mdpi.com/1999-4907/12/7/917

<i>Liriodendron chinense</i> (Hemsley) Sargent is a Class II protected plant in China as natural populations are on the verge of extinction. There is still a lack of systematic research on the genetic resources of its geographic populations. In this study, we used 20 pairs of SSR markers with high polymorphism to analyze a total of 808 <i>L. chinense</i> samples from 22 regions, and 63 <i>Liriodendron tulipifera</i> Linn samples from 2 regions were used as a comparison group. The results revealed a total of 78 alleles in <i>L. chinense</i>, and the average expected heterozygosity (He) was 0.558, showing a low level of genetic diversity. The degree of differentiation of <i>L. chinense</i> was high, with the differentiation coefficient (Fst) as high as 0.302, which is related to the low gene flow (Nm = 0.578). Based on the genetic structure, principal coordinate analysis (PCoA) and phylogenetic analysis of 24 <i>Liriodendron</i> spp. populations, <i>L. chinense</i> and <i>L. tulipifera</i> had obvious differentiation, while the differentiation between <i>L. chinense</i> geographic populations was very large and irregular. Inbreeding appears within the geographic populations, and the level of genetic diversity is very low. In order to protect the genetic diversity of <i>L. chinense</i>, in addition to protecting the existing population as much as possible, artificial cultivation should introduce materials from multiple populations.