• Recently, there has been a debate about whether the temperate forests of East Asia merged or fragmented during glacial periods in the Pleistocene. Here, we tested these two opposing views through phylogeographical studies of the temperate-deciduous walnut tree, Juglans mandshurica (Juglandaceae) in northern and northeastern China, as well as Japan and Korea. • We assessed the genetic structur...

We explored the circumpolar phylogeographic history of the arctic-alpine Juncus biglumis using amplified fragment length polymorphisms (AFLPs), sequences of cpDNA, relative nuclear DNA content and chromosome numbers. The analyses of the AFLP and cpDNA data gave congruent results and revealed three distinct clades. One of them, represented by a single population from the Taymyr peninsula in nort...

The utility of DNA barcoding for identifying representative specimens of the circumpolar tree genus Fraxinus (56 species) was investigated. We examined the genetic variability of several loci suggested in chloroplast DNA barcode protocols such as matK, rpoB, rpoC1 and trnH-psbA in a large worldwide sample of Fraxinus species. The chloroplast intergenic spacer rpl32-trnL was further assessed in ...

The spatial genetic structure of plant populations is determined by a combination of gene flow, genetic drift, and natural selection. Gene flow in most plants can result from either seed or pollen dispersal, but detailed investigations of pollen and seed flow among populations that have diverged following local adaptation are lacking. In this study, we compared pollen and seed flow among 10 pop...

Thlaspi arvense is a well-known annual farmland weed with worldwide distribution, which can be found from sea level to above 4000 m high on the Qinghai-Tibetan Plateau (QTP). In this paper, a phylogeographic history of T. arvense including 19 populations from China was inferred by using three chloroplast (cp) DNA segments (trnL-trnF, rpl32-trnL and rps16) and one nuclear (n) DNA segment (Fe-reg...

Previous analyses of species relationships and polyploid origins in the mimosoid legume genus Leucaena have used chloroplast DNA (cpDNA) restriction site data and morphology. Here we present an analysis of a new DNA sequence data set for the nuclear ribosomal DNA (nrDNA) 5.8S subunit and flanking ITS 1 and ITS 2 spacers, a simultaneous analysis of the morphology, ITS and cpDNA data sets for the...

The introduced Fucus evanescens (hermaphroditic) and the native F. serratus (dioecious) have been in secondary contact along the Danish coast of the Kattegat Sea for 60-100 years and dioecious hybrids have been observed at Blushøj for several years. Hybridization in Fucus is unusual because it appears to always involve a hermaphroditic and a dioecious parental pair. We determined the degree and...

Climatic oscillations and geological events play major roles in shaping species diversity and the distribution of plants. The mechanisms underlying the high level of plant species diversity in eastern Asia are hotly debated. In this study, five cpDNA regions, two mtDNA fragments and one nuclear gene (LEAFY) were employed to investigate species diversification and the historical biogeography of ...

The coding region of the mat K gene and two intergenic spacers, psb A-trn H and trn L(UAA)-trn F(GAA), of cpDNA were sequenced to study phylogenetic relationships of 32 Paeonia species. In the psb A-trn H intergenic spacer, short sequences bordered by long inverted repeats have undergone inversions that are often homoplasious mutations. Insertions/deletions found in the two intergenic spacers, ...

Aquatic plants commonly have extensive geographical distributions, implying few restrictions to dispersal. Here we investigate the postglacial history of an aquatic plant with contrasting sexual systems (monoecy and dioecy), which are predicted to affect dispersal ability. We examined the distribution of cpDNA haplotypes using polymerase chain reaction-restriction fragment length polymorphism (...