Plant Diversity ›› 2020, Vol. 42 ›› Issue (04): 312-318.DOI: 10.1016/j.pld.2020.06.012

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Comparative population genetic analyses suggest hybrid origin of Rhododendron pubicostatum, an endangered plant species with extremely small populations endemic to Yunnan, China

Xuemei Zhanga,b,c, Hantao Qinb,c, Weijia Xied, Yongpeng Maa,b, Weibang Suna,b   

  1. a Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming, 650201, Yunnan, China;
    b Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences (CAS), Kunming, 650201, China;
    c University of Chinese Academy of Sciences, 100049, Beijing, China;
    d Flower Research Institute, Yunnan Academy of Agriculture Sciences, Kunming, 650201, China
  • Received:2020-03-04 Revised:2020-06-22 Online:2020-08-25 Published:2020-10-14
  • Contact: Yongpeng Ma, Weibang Sun
  • Supported by:
    We are grateful to Junbo Yang and Zhirong Zhang to providing technical assistance of lab work and data analysis. Laboratory work was performed at the Laboratory of Molecular Biology at the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences. This work was supported by Science and Technology Basic Resources Investigation Program of China (Grant No. 2017FY100100), the Second Tibetan Plateau Scientific Expedition and Research (STEP) Program (Grant No. 2019QZKK0502), the Young Academic and Technical Leader Raising Foundation of Yunnan Province (No. 2018HB066), Yunnan Innovation Team Program for Conservation and Utilization of PSESP (Plant Species with Extremely Small Populations) (Grant No.2019HC015) and Applied Basic Research Project of Yunnan Province (Grant No. 2018BB010).

Abstract: Gene flow between sympatric congeneric plants is thought to be very common and may pose serious threats to endangered species. In the present study, we evaluate the genetic diversity and divergence of three sympatric Rhododendron species in Jiaozi Mountain using newly developed microsatellites through the Illumina MiSeq sequencing approach. Genetic diversity of all three Rhododendron species studied was moderate in comparison to genetic parameters previously reported from species of this genus. Interestingly, genetic structure analysis of the three species identified a possible hybrid origin of the threatened Rh. pubicostatum. This sympatry should be considered a unimodal hybrid zone, since Rh. pubicostatum is predominant here. Unimodal hybrid zones are uncommon in Rhododendron, despite the fact that hybridization frequently occurs in the genus. Issues pertaining to the conservation of Rh. pubicostatum resulting from admixture of genetic material from its parental species are discussed.

Key words: Rhododendron pubicostatum, Plant Species with Extremely Small, Populations (PSESP), Microsatellite markers, Illumina MiSeq sequencing, Conservation management