Pleistocene glaciations, demographic expansion and subsequent isolation promoted morphological heterogeneity: A phylogeographic study of the alpine Rosa sericea complex (Rosaceae)

Abstract

While most temperate plants probably underwent glacial constriction to refugia and interglacial expansion, another type of interglacial refugia might have existed to maintain alpine plants during warm periods. To test this hypothesis, we applied phylogeographic methods to 763 individuals (62 populations) which belong to 7 taxonomically difficult species of the Rosa sericea complex distributed in alpine regions of the temperate and subtropical zones in eastern Asia. We used three chloroplast (cp) DNA fragments (trnL-trnF, ndhF-rpl32 and ndhJ-trnF) approximately 3,100 bp and nuclear microsatellite (nSSR) on eight sites to determine whether cold tolerant plants experienced expansion during the Pleistocene. The neutral test and mismatch distribution analysis (MDA) indicated that whole populations and major lineages of the Qinghai-Tibet Plateau (QTP) underwent expansion during the middle to late Pleistocene. Environmental niche modeling (ENM) indicates more suitable habitats during the Last Glacial Maximum (LGM) than at present. We concluded that the demographic history of R. sericea, which diverged in the middle Pleistocene, was mostly affected by climatic oscillations instead of by geographical barriers. The low genetic divergence, as well as the weak phylogenetic structure in the R. sericea complex both support treating this complex as a single taxon.

Chloroplast View of the Population Genetics and Phylogeography of a Widely Distributed Shrub Species, <I>Rhododendron dauricum</I> (Ericaceae)

“…Phylogeographic Structure and Inference of Demographic Patterns -Our results on the phylogeographic structure of R. dauricum were consistent with previous studies of temperate montane flora in northeastern China, which were strongly structured phylogeographically (Chen et al 2008;Tian et al 2009;Chen et al 2012b). In this study, N ST was significantly …”

“…When confronted with chloroplast marker choice in Rhododendron, Ericaceae, or other related families, these six primer pairs and associated chloroplast regions may be priorities. From the sequences amplified by those primer pairs, our results showed that the haplotype diversity (H d = 0.834) of R. dauricum was higher than that of other temperate shrub or small-sized tree species, such as R. delavayi ( Gao et al 2015), and it was also higher than the mean for cpDNA as reported by Petit et al (2005) in 170 species of angiosperms (H d = 0.670).…”

“…Our results are consistent with the latter view. Habitat fragmentation formed barriers against gene flow, further leading to genetic diversification, accelerating variation and even speciation (DeChaine and Martin 2004;Li et al 2012;Gao et al 2015). Under this hypothesis, the long-term isolation among multiple refugia and little admixture among populations of different origins have caused substantial genetic diversification in R. dauricum.…”

Examining the interglacial high‐elevation refugia scenario in East Asian subtropical mountain systems with the frog species Leptobrachium liui

“…The East Asian mainland differs from Europe and North America by having remained largely unglaciated during the Pleistocene (Feng, Mao, Sandel, Swenson, & Svenning, ; Hewitt, ; Li, Shu, Zhou, Zhao, & Zhang, ). Relevant studies in this region are rare and have primarily focused on southwestern China and adjacent areas with their complex topography and high mountains, such as the Himalayas (e.g., Gao, Zhang, Gao, & Zhu, ; He & Jiang, ).…”

A review of phylogeography: biotic and abiotic factors

“…However, it is difficult to study the population expansion of trees as their life span is very long, but still there are methods like radiocarbon dating which solve this problem to some extent are available (Bennett, 1983). Researchers studied population expansion and successive isolation stimulated morphological heterogeneity in Rosa sericea complex (Gao, Zhang, Gao, & Zhu, 2015). They studied three chloroplast DNA fragments such as ndhJ-trnF, trnL-trnF and ndhF-rpl32 and nuclear microsatellite to confirm whether cold tolerant plants accomplished expansion during the Pleistocene.…”