Delimiting 33 Carpinus (Betulaceae) species with a further phylogenetic inference. Issue 3 (21st February 2022)

• Record Type: Journal Article
• Authors: Dong, Congcong; Lu, Zhiqiang; Zhang, Han; Liu, Jianquan; Li, Minjie
• Editors: Brennan, Adrian C
• Is Part Of: AoB plants. Volume 14:Issue 3(2022)
• Publication Date: 2022-02-21
• Subjects: Carpinus -- ITS sequences -- Phylogeny -- Species delimitation; Plants -- Periodicals; Botany -- Periodicals; 580.5
• DOI: 10.1093/aobpla/plac006
• Languages: English
• ISSNs: 2041-2851

Abstract

Abstract: Carpinus (Betulaceae) has approximately 52 species distributed in the Northern Hemisphere, with many species of Carpinus found in China. However, the species boundaries and phylogenetic relationships remain poorly understood. This study reported ITS sequences for 225 individuals of 33 Carpinus species, mainly from China. We also included eight Ostrya species in our analyses, the closely related sister group of Carpinus . We aimed to delimit these species based on ITS sequences and clarify their phylogenetic relationships by constructing tree-like topology and networks at population level. We found that only 17 of 33 species could be delimited from the closely related ones based on species-specific mutations in ITS sequence variation, including all species of sect. Distegocarpus, and sect. Carpinus subsect . Carpinus. Carpinus subsect . Carpinus contained two endangered species, although one seemed to be a recently originated allopolyploid species with genetic additivity from two likely parents in the ITS sequence variation. Sixteen species of sect. Carpinus subsect. Polyneurae were classified into three species complexes, in each of which two or more could be not distinguished from each other. The closely related species of these complexes may still diverge at the early stage without genetic distinction in the nuclear ITS sequences because of too short of divergence time and frequent gene flow. Otherwise, some species may be established based on the intraspecific variations without genetic bases for an independently evolving unit. Abstract : By using nuclear ITS sequence of the genus Carpinus and its sister genus sampled from its distribution centre in China, a phylogenetic analysis was performed as a test of species delimitation, aiming to providing accurate species boundaries and phylogenetic relationships for conservation or other aims. Our results showed that 17 of 33 species could be delimited from the closely related ones, while the remaining 16 species were classified into three species complexes because of too short a divergence time and frequent gene flow.