An integrative approach to the delineation of locally endemic species: A case study of Vitis baihuashanensis (Vitaceae) and its implication for conservation management

Abstract

Species definition and classification have long been the subject of controversy, and name changes can often be a source of frustration for both conservationists and the public. Vitis baihuashanensis is a critically endangered grapevine endemic to Beijing with only two remaining wild individuals. Although formerly treated as a synonym of V. amurensis, it was later listed in the List of National Key Protected Wild Plants (LNKPWP) in 2021. Here, we evaluated the taxonomic identity of V. baihuashanensis based on phylogenomic inference and population genetic analysis, and tested the species boundaries under various major species concepts (biological, morphological, ecological, phylogenetic, and integrative species concepts). Phylogenetic inference revealed that the amurensis-baihuashanensis clade was monophyletic, samples of V. baihuashanensis nested within the V. amurensis node. Population genetic analysis demonstrated that V. baihuashanensis samples clustered with V. amurensis. Our findings from field observations, morphological comparisons, pollination experiments, and genetic analyses indicate that V. baihuashanensis and V. amurensis are the same species under the integrative species concept, and support the synonymy of V. baihuashanensis under V. amurensis. Given that V. baihuashanensis was listed in the LNKPWP, we suggest that it be removed in the next update of the list because of limited financial resources. Nevertheless, the two wild individuals deserve conservation attention because of their distinct leaf characteristics and potential of cold tolerance, which could have important applications in the horticulture and grape industries. Our study provides multiple lines of evidence for clarifying the identity of a taxonomically questionable species, as well as valuable suggestion with conservation and management implications.

Keywords

• Gen-morph species concept
• Integrative taxonomy
• Key protected wild plant
• Phylogenetic species concept
• Species delimitation
• Vitis baihuashanensis