Extensive population expansion of Pedicularis longiflora (Orobanchaceae) on the Qinghai‐Tibetan Plateau and its correlation with the Quaternary climate change

Abstract

Population founding and spatial spread may profoundly influence later population genetic structure, but their effects are difficult to quantify when population history is unknown. We examined the genetic effects of founder group formation in a recently founded population of the animal-dispersed Vaccinium membranaceum (black huckleberry) on new volcanic deposits at Mount St Helens (Washington, USA) 24 years post-eruption. Using amplified fragment length polymorphisms and assignment tests, we determined sources of the newly founded population and characterized genetic variation within new and source populations. Our analyses indicate that while founders were derived from many sources, about half originated from a small number of plants that survived the 1980 eruption in pockets of remnant soil embedded within primary successional areas. We found no evidence of a strong founder effect in the new population; indeed genetic diversity in the newly founded population tended to be higher than in some of the source regions. Similarly, formation of the new population did not increase among-population genetic variance, and there was no evidence of kin-structured dispersal in the new population. These results indicate that high gene flow among sources and long-distance dispersal were important processes shaping the genetic diversity in this young V. membranaceum population. Other species with similar dispersal abilities may also be able to colonize new habitats without significant reduction in genetic diversity or increase in differentiation among populations.

Range shifts of Potentilla fruticosa on the Qinghai-Tibetan Plateau during glacial and interglacial periods revealed by chloroplast DNA sequence variation

“…This conclusion is supported by the unimodal mismatch distribution of the northeastern populations (Figure 4a), suggesting historical population expansion, and by the star-shaped phylogeny of haplotypes derived from haplotype A (Figure 2), the reduced levels of haplotypic and nucleotide diversity (Table 1), and the prevalence of haplotype A in the northeastern populations (Figure 1). The homogeneous genetic pattern in the northeastern populations is consistent with the AMOVA result, which showed relatively low genetic variation among populations (48.7%) in comparison with other alpine plant species on the Plateau (Chen et al, 2008;Yang et al, 2008;Wang et al, 2009). These patterns are consistent with the results of a simulation study in which sudden expansion from a few populations produced reduced allele diversity and areas of genetic homogeneity (Avise, 2000).…”

“…Wang et al (2009) suggested that Aconitum gymnandrum has survived on high-altitude parts of the central Plateau throughout the Quaternary. In contrast, Metagentiana striata and Pedicularis longiflora probably expanded from refugia on the eastern edge to the central Plateau during the interglacial and postglacial periods (Chen et al, 2008;Yang et al, 2008). Therefore, these three investigated alpine species do not share a common phylogeographical history.…”

“…Recent phylogeographic studies have examined the demographic history of alpine plants across the Plateau (Chen et al, 2008;Yang et al, 2008;Wang et al, 2009). Wang et al (2009) suggested that Aconitum gymnandrum has survived on high-altitude parts of the central Plateau throughout the Quaternary.…”

Dispersals of Hyoscyameae and Mandragoreae (Solanaceae) from the New World to Eurasia in the early Miocene and their biogeographic diversification within Eurasia

“…The recent range expansion from the 'hot spot' of the mountains of the southeastern TP has been observed in other plants and birds at the population level. Examples include Juniperus przewalskii (Cupressaceae) , Metagentiana striata (Gentianaceae) (Chen et al, 2008), Pedicularis longiflora (Orobanchaceae) (Yang et al, 2008), Picea crassifolia (Pinaceae) (Meng et al, 2007), and the red-necked snow finch Pyrgilauda ruficollis (Qu et al, 2005). Phylogeographic studies on these species show that populations from the wide range of the platform are dominated by one or a few haplotypes and are mostly nested within diverse haplotypes from the southeastern mountains of the TP.…”

Genetic consequences of postglacial colonization by the endemic Yarkand hare (Lepus yarkandensis) of the arid Tarim Basin

“…In contrast, studies on the Asian biota have been rather limited. The complex topography of East Asia probably provided refugia for species during times of Pleistocene glaciation [14], yet only a few plant and bird species restricted to the Qinghai-Tibetan Plateau (QTP) have been evaluated [15][16][17][18][19][20].…”