Disjunct distribution of chloroplast DNA haplotypes in the understory perennial Veratrum album ssp. oxysepalum (Melanthiaceae) in Japan as a result of ancient introgression

Abstract

Summary• The Quaternary climatic changes resulted in range shifts of species, providing chances for hybridization. However, the genetic signatures of such ancient introgression have rarely been reported. To investigate such signatures, we performed a phylogeographical study on the perennial plant Veratrum album ssp. oxysepalum, which may have hybridized long ago with another congeneric species, V. stamineum.• Sequence variations in chloroplast DNA (cpDNA) were examined in 43 populations in Japan and adjacent areas. Phylogenetic analyses of different cpDNA haplotypes were conducted on the basis of cpDNA and nuclear ribosomal internal transcribed spacer (nrITS) variations.• In the Japanese archipelago, two major groups of haplotypes were detected, one of which was distributed in a disjunct pattern. The major haplotype, occupying the central part of the species' distribution, formed a monophyletic group with V. stamineum in phylogenetic trees on the basis of cpDNA variation, although the two species did not form a monophyletic group in phylogenetic trees on the basis of nrITS variation.• Historical hybridization between V. album ssp. oxysepalum and V. stamineum in refugia during the Quaternary climatic oscillations, and the resulting chloroplast capture of V. stamineum by V. album ssp. oxysepalum, are most probably responsible for the disjunct distribution of cpDNA in V. album ssp. oxysepalum.

Genetic differentiation and delimitation of Pugionium dolabratum and Pugionium cornutum (Brassicaceae)

“…Schluter 2009; Schemske 2010) and partly concur with the limited number of empirical studies involving one or two similar genetic markers in plants (e.g. Bai et al 2010;Kikuchi et al 2010;Mims et al 2010;Wang et al 2011a). …”

A strong ‘filter’ effect of the East China Sea land bridge for East Asia’s temperate plant species: inferences from molecular phylogeography and ecological niche modelling of Platycrater arguta(Hydrangeaceae)

“…J5; Figures 1a and 3), is strongly suggestive of a two-refugia scenario and a narrow contact zone between the two lineages. Interestingly, this putative contact region coincides with a well-known inter- and intraspecific suture zone of Japan’s temperate flora and fauna [14,108,109,12]. On the other hand, the Tpi data are more consistent with a multiple-refugia scenario, that is, haplotypes are largely restricted to particular (sub)regions and/or populations, while still showing a relatively small amount of shared polymorphisms, mainly (but not exclusively) among adjacent sites (Figure 2a).…”

Phylogenetic and Taxonomic Status Analyses of the Abaso Section from Multiple Nuclear Genes and Plastid Fragments Reveal New Insights into the North America Origin of Populus (Salicaceae)

“…Abaso ( Figure 1 ). Given that biparentally inherited nuclear gene loci are more effective for species delimitation than maternally inherited ptDNA markers in many angiosperm genera (Bai et al, 2010; Kikuchi et al, 2010), and the extant P. mexicana species are morphologically distinct and reproductively isolated from other NA species (Eckenwalder, 1996a), it is quite reasonable that P. mexicana would form its own section. In addition, the placement of P. mexicana in a basal position of the genus Populus , which is consistent with Eckenwalder’s interpretation based on morphological traits, the leaf morphology of extant P. mexicana was similar to the oldest poplar fossil from the Eocene (Manchester et al, 1986) together suggested that section Abaso may be an ancestral lineage.…”