J Syst Evol ›› 2021, Vol. 59 ›› Issue (3): 515-523.DOI: 10.1111/jse.12584

• Research Articles • Previous Articles     Next Articles

Polyphyly and species delimitation of Picea brachytyla (Pinaceae) based on population genetic data

Le-Ke Lyu1†, Dong-Lei Wang1†, Long Li2†, Ying-Ying Zhu1, De-Chun Jiang1, Jian-Quan Liu1,2, and Xiao-Ting Xu1*   

  1. 1 Key Laboratory for Bio‐resource and Eco‐environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
    2 State Key Laboratory of Grassland Agro‐Ecosystem, Institute of Innovation Ecology and College of Life Sciences, Lanzhou University, Lanzhou 730000, China
  • Received:2019-04-14 Accepted:2020-03-09 Online:2020-03-13 Published:2021-05-01

Abstract: Accurate species delimitation is fundamental to biodiversity conservation. The endangered spruce Picea brachytyla (Franch.) E. Pritz. was suggested to be polyphyletic based on a limited number of samples in previous studies. To evaluate polyphyly of P. brachytyla, we sampled 139 individuals from 16 populations across most of its distributional range, plus representatives of two related species, Picea likiangensis (Franch.) E. Pritz. and Picea wilsonii Mast. We sequenced 13 nuclear loci and three chloroplast and two mitochondrial loci for the following species delimitation. Phylogenetic analyses of nuclear loci grouped all individuals of P. brachytyla from Sichuan and Chongqing into one distinct lineage and those from Yunnan and Tibet (southern distribution) nested within the P. likiangensis species complex. Structure analyses confirmed this result. Networks of chloroplast DNA haplotypes similarly showed that P. brachytyla from the southern distribution nested within the P. likiangensis species complex, whereas haplotypes for the northern distribution comprised a separate and well-supported lineage. These results suggest that P. brachytyla from the southern distribution is a part of the P. likiangensis species complex and should be removed from P. brachytyla. Our study highlights the utility of population genetic evidence in delimitating endangered species and understanding the conservation status of such species.

Key words: Picea brachytyla, polyphyly, population genetic data, species delimitation