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The Khanka Lowland forest-steppe is the most eastern outpost of the Eurasian steppe biome. It includes unique grassland plant communities with rare steppe species. These coenosis have changed under the influence of anthropogenic activity, especially during the last 100 years and included both typical steppe species and nemoral mesophytic species. To distinguish these ecological groups of plants the random forest method with three datasets of environmental variables was applied. Specifically, a model of classification with the most important bioindices to predict a mesophytic ecological group of plants with a sensitivity greater than 80% was constructed. The data demonstrated the presence of steppe species that arrived at different times in the Primorye Territory. Most of these species are associated with the Mongolian-Daurian relict steppe complex and habit in the Khanka Lowland. Other species occur only in mountains in Primorye Territory and do not persist in the Khanka Lowland. These findings emphasize the presence of relict steppe communities with a complex of true steppe species in the Khanka Lowland. Steppe communities exhibit features of anthropogenic influence definitely through the long land use period but are not anthropogenic in origin. The most steppe species are located at the eastern border of distribution in the Khanka Lowlands and are valuable in terms of conservation and sources of information about steppe species origin and the emergence of the steppe biome as a whole. [ABSTRACT FROM AUTHOR]

Hypecoum erectum L., a widespread species in northern Eurasia, is a valuable medicinal plant, but its chloroplast genome has not previously been reported. We determined its complete chloroplast genome using a high-throughput sequencing technique. Its total length was 169,241 bp, consisting of a large single-copy region of 93,301 bp and a small single-copy region of 17,316 bp, separated by a pair of inverted repeat regions of 29,312 bp. A total of 140 genes were annotated, including 91 protein coding genes, 41 tRNA genes, and eight rRNA genes. The phylogenetic analysis shows that H. erectum and H. zhukanum of the subfamily Hypecoideae are monophyletic with the highest support. [ABSTRACT FROM AUTHOR]

Micranthes nelsoniana possesses multiple different variants and numerous chromosomes. Based on the internal transcribed spacer (ITS) and chloroplast (cp)DNA sequences, the phylogeography of M. nelsoniana and its relatives in Northeast Asia was investigated, with extensive sampling around the Kuril Islands. The Arctic–Asian continent and a clade of marginal islands were the two main groupings that comprised the ITS phylogenetic tree. The island clade was separated into five well-supported clades: Kamchatka and Hokkaido highlands, Kuril–Aleutian Islands, southern Kuril Islands, Japanese archipelago, and Primorye region. Micranthes fusca was found in Japan and in the southern Kuril Islands. It is a separate species that created several types of hybrids between M. nelsoniana in the centre of the Kuril Islands based on a comparison of the ITS and cpDNA networks. Micranthes nelsoniana and M. ohwii appear to have hybridized in the northern Kuril Islands. Cytological investigation on the local species of M. nelsoniana showed that the chromosomal numbers are: 2 n  = 24, 26, 28, 30, 50, and 80. Among them, two usual numbers to this area, 2 n  = 24 and 50, appear to encourage interspecific gene exchange. The genomes of Hokkaido plants with high chromosome counts were cloned, revealing that they contained genes of both continental and marginal origins. This study revealed the crucial role of marginal islands along Northeast Asia in the genetic diversity of M. nelsoniana and related species. [ABSTRACT FROM AUTHOR]

The Japanese subalpine zone is dominated by an ecologically important forest biome, subalpine coniferous forest, constituting a distinct assemblage of cold‐tolerant angiosperm and conifer species. While being relatively intact compared to other forest biomes in Japan, subalpine coniferous forests are under significant threat from deer browsing, global warming and small population size effects. However, there is a severe lack of genetic resources available for this biome's major constituent plant species. This study aimed to develop chloroplast genome‐based genetic resources for 12 widespread subalpine tree and shrub species (7 angiosperms and 5 conifers) via genome skimming of whole‐genomic DNA using short reads (100–150 bp in length). For 10 species, whole chloroplast genomes were assembled via de novo‐based methods from 4 to 10 individuals per species sampled from across their ranges in Japan and, for non‐Japanese endemic species, elsewhere in northeast Asia. A total of 566 single nucleotide polymorphisms for Japanese samples and 768 for all samples (varying from 2 to 202 per species) were identified which were distributed in geographically restricted lineages in most species. In addition, between 9 and 58 polymorphic simple sequence repeat regions were identified per species. For two Ericaceae species (Rhododendron brachycarpum and Vaccinium vitis‐idaea) characterised by large chloroplast genomes, de novo assembly failed, but single nucleotide polymorphisms could be identified using reference mapping. These data will be useful for genetic studies of species taxonomic relationships, investigating phylogeographic patterns within species, developing chloroplast‐based markers for conservation genetic studies and has potential application for studies of environmental and ancient DNA. [ABSTRACT FROM AUTHOR]

Commonly considered bispecific, Acorus is one of the most phylogenetically isolated angiosperm genera that forms the order Acorales sister to the rest of the monocots. The Acorus calamus group is widely distributed in the Holarctic regions of Eurasia and America and has strong medicinal and other practical uses since prehistoric times. Earlier studies interpreted native diploids and invasive triploids occurring in North America as two species that differed in morphology and distribution ranges. In contrast, diploids, triploids, and tetraploids occurring in Eurasia are commonly interpreted as one species because they reportedly cannot be distinguished in collections. We resolve the controversy over taxonomic concepts between Eurasia and America and provide the first detailed multidisciplinary account of Acorus in temperate Asia. We used plastid and nuclear markers, leaf anatomy, seed micromorphology, pollen stainability, flow cytometry, and direct chromosome counts. Diploids and tetraploids show stable molecular and micromorphological differences. Triploids are their sterile hybrids, with the plastid genome inherited from the diploid parent. Diploids of America and Asia tend to differ in leaf characters. Coadaptative coexistence with pollinating beetles Platamartus jakowlewi and Sibirhelus corpulentus (Kateretidae) is conserved between diploids and tetraploids and over a distance of 4700 km between Japan and Western Siberia. Diploids are self‐compatible and can set seeds in the absence of kateretid beetles. Tetraploids are self‐incompatible and/or cannot set seeds in the absence of Platamartus and Sibirhelus. Diploids (A. americanus) and tetraploids (A. verus) are two biological species; the former has two subspecies. Acorus calamus should be restricted to triploids; it apparently first evolved in temperate Asia. Diploids mostly occur in much cooler climates than triploids and tetraploids. Accessions of A. verus and A. calamus from tropical Asia are apparently derived from ancient introductions. Our data provide a new framework for the pharmacological use of Acorus. [ABSTRACT FROM AUTHOR]

The green alder Alnus alnobetula s. l., a widely distributed subarctic-alpine shrub species, has been studied using three chloroplast DNA regions: trnH-psbA, trnS-trnG, and psaA-trnS. In addition, new chloroplast primers coding the trnT-GGT cpDNA regions and five cpDNA microsatellite loci (cpSSR) have been developed for this species. The population subdivision is very high (Nst = 0.869, Gst = 0.807, Fst = 0.883), suggesting a distinct phylogeographic structure (Nst > Gst, p < 0.0001) and a sharp contrast between the haplotype-rich eastern part of the species range and the almost completely uniform western part (Siberia, Ural). According to a phylogenetic analysis, the common haplotype of A. alnobetula subsp. fruticosa in the western part of the range originated from northeastern refugia (West Beringia) as a result of interglacial recolonization, including bottleneck events. Three highly divergent cpDNA lineages of green alder that have been resolved in the Russian Far East are largely concordant with A. alnobetula subsp. kamtschaticа, A. alnobetula subsp. mandschurica, and A. alnobetula subsp. maximowiczii. The populations of Sakhalin Island are divided into three phylogeographic groups (southern, central, and northern) corresponding to the different floristic zones and different subspecies. The green alder populations from central Sakhalin have a haplotype-rich composition including different genetic lineages that confirm the existence of a hotspot of genetic diversity in this part of the island. [ABSTRACT FROM AUTHOR]

Rhododendron brachycarpum is an ecologically important tree species with a narrow, fragmented geographic range in East Asia. R. brachycarpum is distributed primarily in Korea and Japan, with two small isolated populations in the Russian Far East. We obtained 124 samples from seven populations of R. brachycarpum, representing all geographical regions of its entire natural range, and we utilized microsatellite markers to estimate the level of genetic variation within and between populations. A total of 200 alleles based on 14 nuclear microsatellites loci were identified. High diversity (He = 0.556–0.626) was observed in populations from Korea and Japan. In contrast, in peripheral populations from Russia diversity was quite low (He = 0.100–0.369) with a high coefficient of inbreeding (FIS = 0.471–0.526). Strong population differentiation (FST = 0.356) and clear distinction among the geographical groups (FCT = 0.227) were revealed. Bayesian clustering and principal coordinate analyses indicated that two Russian populations, Sikhote-Alin and Iturup Island, represent extremes of two different migration routes, with one derived from the mainland and one from Japan. [ABSTRACT FROM AUTHOR]

The vast territory of East Asia, including southwestern Beringia, is considered to have been almost ice free during the Pleistocene. Cold-resistant flora may have persisted in this region expanding or contracting its range during the climate cooling. Only a few plant genera have been studied with a sampling area across their entire geographic range in East Asia; therefore, the understanding of the biogeographic history of alpine flora in this region remains limited. In the present study, genetic variation and population structure in 21 populations of the alpine shrub Rhododendron aureum across its range in East Asia were assessed using 18 microsatellite loci. Phylogenetic analyses revealed three main genetic groups: Siberia, Northeast, and North Pacific. According to the geographical pattern of genetic diversity, the North Pacific group includes populations from Kamchatka, south of Russian Far East, and territories close to central Japan. This group is the most diverse and likely diverged earlier than the Siberia and Northeast groups. Ecological niche modeling predicts range expansion of this species during the period of cooling and, together with demographic history, suggests that the divergence between the three main genetic groups predated the Last Glacial Maximum. Similar to other cold-resistant species such as Larix sibirica and Juniperus communis, the pattern of genetic diversity of R. aureum supports the survival of the species at high latitudes during the Pleistocene with limited contribution of the southern populations to expansion of the species range to the Northeast region and Siberia. [ABSTRACT FROM AUTHOR]