Plant Diversity ›› 2021, Vol. 43 ›› Issue (03): 225-233.DOI: 10.1016/j.pld.2020.12.007

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Genetic diversity and structure of the endemic and endangered species Aristolochia delavayi growing along the Jinsha River

Yu-Long Yua,b, Hui-Chun Wangb,c, Zhi-Xiang Yud, Johann Schinnerle, Rong Tangb,c, Yu-Peng Genga, Gao Chenb,f   

  1. a School of Ecology and Environmental Science, Yunnan University, Kunming, 650091, China;
    b Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China;
    c University of Chinese Academy of Sciences, Beijing, 100049, China;
    d Sichuan Panzhihua Cycas National Nature Reserver Bureau, Panzhihua, 617000, China;
    e Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030, Vienna, Austria;
    f CAS Key Laboratory for Plant Biodiversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China
  • Received:2020-07-19 Revised:2020-12-12 Published:2021-06-28
  • Contact: Yu-Peng Geng, Gao Chen
  • Supported by:
    We thank Chencan Liao, Maoyao Yan and Qi Yu for their assistance in collecting samples. We appreciate Zhi Chen for picture optimization. Support for this study was provided by grants from the NSFC (National Natural Science Foundation of China)-Yunnan Joint fund to support key projects (No. U1602264) and Yunnan Ten Thousand Talents Plan Young & Elite Talent Project to G. Chen (YNWR-QNBJ-2018-017); and NSFC (National Natural Science Foundation of China) (No. 31660057) to Y.P. Geng; Science & Technology Basic Resources Investigation Program of China for Survey and Germplasm Conservation of PSESP in Southwest China (2017FY100100) to W.B. Sun.

Abstract: The traditional medicinal plant, and endangered species Aristolochia delavayi (Aristolochiaceae) is an endemic species in China and occurs in the warm and dry areas along the Jinsha river. It is also a specific host of the larvae of Byasa daemonius, a vulnerable butterfly. In this study, 15 pairs of polymorphic microsatellite primers of A. delavayi were designed and screened based on the Simple Sequence Repeats (SSR) loci found by using the results of genome skimming. Based on these 15 SSR markers, the genetic diversity and structure of 193 individuals from ten natural populations were analyzed in detail. In comparison to other endemic and endangered plants in the region, the population of A. delavayi possess a relatively high genetic diversity (He = 0.550, I = 1.112). AMOVA analysis showed that 68.4% of the total genetic diversity was within populations and 31.6% of the variation occurred among populations. There was a significant genetic differentiation among natural populations of A. delavayi detectable, with low gene flow (Nm = 0.591). This might be attributed to geographical barriers and limited seed dispersal. To test the isolation by distance (IBD), we performed Mantel test, which showed a significant correlation between the geographic and genetic distances. In order to cope with the possible biases caused by IBD, we additionally performed Bayesian genetic cluster analyses and principal coordinate analysis (PCoA). The final cluster analysis revealed three groups with distinct geographical distribution. Habitat fragmentation and limited gene flow between these populations may be the main reasons for the current genetic structure. For conservation of this species, we suggest to divide its populations into three protection management units, with subsequent focus on the Yongsheng and Luquan populations which experienced a genetic bottleneck event in the past.

Key words: Aristolochia delavayi, Conservation biology, Genetic diversity, Genetic structure, Microsatellites, Genome skimming