Resolving the Speciation Patterns and Evolutionary History of the Intercontinental Disjunct Genus Corylus (Betulaceae) Using Genome-Wide SNPs

作   者：Zhen Yang, Tian-Tian Zhao*, Qing-Hua Ma, Li-Song Liang and Gui-Xi Wang*
期刊名称：frontiers in plant science
影响因子：3.677
卷 期 号：
页     码：
关键词：Corylus, speciation, recombination, hybridization, divergence time estimation, ancestral area reconstruction, genome-wide SNPs
论文摘要：
Understanding the underlying mechanisms of species origin, divergence, and
distribution patterns of the intercontinental disjunct taxa has long fascinated botanists.
Based on 4,894 genome-wide single-nucleotide polymorphism dataset, we present
a molecular phylogenetic reconstruction of genus Corylus (Betulaceae), which have
a disjunct distribution between Eurasia and North America (NA). The aim is to
explore the speciation patterns and evolutionary relationships of Corylus species by
establishing a general phylogenetic framework with extensive sampling. Both the
molecular phylogeny inferred from recombination-free dataset and structure analysis
support the division of Corylus into four major clades (A–D). Recombination tests and
hybridization detection reveal extensive recombination and hybridization events among
different clades, which have potentially influenced the speciation process of Corylus.
Divergence time estimation indicates that recent common ancestor (MRCA) of Corylus
occurred in late Eocene ( 36.38 Ma) and subsequent rapid diversification began during
Miocene. Ancestral area reconstruction shows that Corylus originated from southwest
China. The arrival of two clades (Clades B and C) to NA was well supported by the
long distance dispersal crossing the Bering land bridge. The Himalayas, European-
Mediterranean area, and other distribution regions are primarily the recipients of
dispersal taxa. Vicariance after dispersal plays an important role in speciation.