Notes on genetic variation in Sedum sarmentosum (Crassulaceae): Implications for the origin of southern Korean populations

7 p., 1 mapa, tablasThe succulent herbaceous perennial Sedum sarmentosum commonly grows in the southern part of the Korean Peninsula. It is a species native to China, most likely introduced into Korea due to its edible and medicinal uses. If plants were introduced from a single source, we would expect no or low levels of genetic variation in Korean populations. Alternatively, if plants were introduced from multiple sources, we would expect, in contrast, high levels of genetic diversity. To test which is more likely, we surveyed the degree of allozyme variation in ten populations of this species from southern Korea. We found that S. sarmentosum was monomorphic at all fifteen allozyme loci. How- ever, two congeners (S. polytrichoides and S. kamtschaticum) and two related species (Hylotelephium ussuriense and H. verticillatum) maintain moderate to high levels of genetic diversity (H = 0.144, 0.203, 0.201, and 0.204, respec- tively). We suggest that southern Korean populations of S. sarmentosum likely descended from a single introduction of a few plants and then became naturalized exclusively via vegetative spreading (as plants in Korea, but also as occurs in other parts of its native and naturalized range, are sterile).This research was supported by the National Institute of Biological Resources, Republic of Korea to M.G. C. and the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2013R1A1A2063524 and NRF-2013R1A1A 3010892 to M.G.C. and M.Y.C., respectively). This research was also supported by the grant no. 201630I024 (“Proyecto Intramural Especial, PIE” from the CSIC, Spain) to J.L.-P.Peer reviewe

Is the Baekdudaegan “the Southern Appalachians of the East”? A comparison between these mountain systems, focusing on their role as glacial refugia

11 p., mapas, tablasBased on genetic studies and palaeoecological surveys, the main Korean mountain range, the so- called “Baekdudaegan” (BDDG), has been recently suggested to be a major glacial refugium at the Last Glacial Maximum (LGM) for the boreal and temperate flora of northeastern Asia. On the basis of its shared role as a glacial refugium, and on a series of striking similarities in floristic richness and orographic features, the BDDG would constitute a sort of “eastern counterpart” of the Southern Appalachians. Given its floristic, biogeo- graphic, and cultural value, the BDDG merits high priority for conservation.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF- 2013R1A1A2063524 and NRF-2013R1A1A3010892 to M.G.C. and M.Y.C., respectivelyPeer reviewe

Genetic Evidence of a Progenitor-Derivative Species Pair in East Asian "Lilium"

8 p., tablas, mapasBoreal Lilium distichum and temperate L. tsingtauense are morphologically very similar, thus they have been placed in the section Martagon. Recent molecular phylogenetic analyses revealed that L. distichum and L. tsingtauense are indeed the most closely related species within that section. Lilium distichum has a wider geographic range and a broader niche than L. tsingtauense. We hypothesized that L. distichum— L. tsingtauense might be a classical “progenitor—derivative” (P–D) species pair and examined the levels of allozyme diversity in the two species in South Korea. Whereas the allelic composition of L. tsingtauense represented a subset of L. distichum, the former had significantly lower allozyme variability at both the population and the species levels than the latter. Except for the locus Fe (fluorescent esterase), allele frequencies of L. distichum were very similar to those of L. tsingtauense. Accordingly, pairwise genetic identities between populations of L. distichum and L. tsingtauense were very high, with a mean of 0.919. Our allozyme results support the hypothesis that L. tsingtauense is a derivative species of the progenitor L. distichum.This research was supported by the Basic Science Program through the National Research Foundation of Korea (NRF-2013R1A1A3010892) funded by the Ministry of Education, Science and Technology, the Republic of Korea to M.Y.C.Peer reviewe

Population genetic structure of Sedum polytrichoides (Crassulaceae): Insights into barriers to gene flow

10 p., tablas, gráf.An area comprising Juwangsan National Park and its adjacent mountains (southeastern Korean Pen- insula) is a good model system for testing the effects of physical barriers to gene flows in plant populations. We predicted that plant species consisting of isolated populations are genetically more differentiated than those that are rather continuously distributed. Most populations of Sedum polytrichoides occur in four isolated valleys, and we assessed the genetic variability and structures using twelve allozyme loci in ten populations. We also com- pared the present results to earlier findings pertaining to the two co-occurring herbs Hylotelephium ussuriense (≡ Sedum ussuriense) (growing only in the four isolated valleys) and S. kamtschaticum (rather continuously dis- tributed). We found moderate levels of within-population genetic variation in S. polytrichoides (H = 0.112). Estimates of among-population divergence in S. polytrichoides were also moderate (F = 0.250) and, as expected, very similar to that of H. ussuriense (0.261) but considerably higher than the variation in S. kamtschat- icum (0.165). An analysis of molecular variance (AMOVA) revealed that S. polytrichoides and H. ussuriense had higher percentages of among-valley variation (19% each) than S. kamtschaticum (4%). Most of this vari- ation, as also indicated by the STRUCTURE program, was due to differences in genetic profiles between the two central valleys. We concluded that the genetic differences observed between species (S. kamtschaticum vs. S. polytrichoides and H. ussuriense) are mainly due to differences in their distribution within the study area.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2013R1A1A2063524 and NRF-2013R1A1A3010892 to M.G.C. and M.Y.C., respectivelyPeer reviewe

Blow to the northeast? Intraspecific differentiation of populus davidiana suggests a northeastward skew of a phylogeographic break boundary in East Asia

Aim There is increasing interest in the role that biological traits, and historical and biogeographic processes, play in the formation of phylogeographic patterns. An arid belt that once existed in northern China might have affected many plants, but this has yet to be tested in an arid-tolerant, wind-dispersed species. Here, we tested how intrinsic and extrinsic factors have affected the phylogeography of Populus davidiana. Location East Asia. Methods Genetic variation was surveyed across 40 populations (555 individuals) covering the Chinese range of P. davidiana, using 16 nuclear microsatellite loci (nSSRs) and four chloroplast fragments (cpDNA). Demographic and migration hypotheses were tested using coalescent-based approaches, and the present and past potential distributions were predicted using species distribution modelling. Results Molecular data divide P. davidiana into two lineages, north-eastern China (NECR) and central and northern China (CNCR); however, the dividing line is around 118ºE for nSSRs, but 122ºE for cpDNA. The range and habitat of the two lineages barely overlap at present, and their ecological separation may have initiated around the Pliocene-Quaternary boundary, when major intraspecific cpDNA clades diverged. NECR and CNCR experienced post-glacial north-eastward and northward range shifts respectively. Bi-directional historical gene flow was detected between NECR and CNCR for both bi-parentally inherited nSSRs and maternally inherited cpDNA. Demographic inferences suggest a severe bottleneck for CNCR and especially NECR, around the latest Pleistocene. Main conclusions The phylogeographic break within P. davidiana reflects the impacts of biogeographic history, climate and biological traits. Its plumed, wind-dispersed seeds might be especially significant because prevailing south-western spring winds may have moved the NECR-CNCR boundary further east than similar phylogenetic breaks in other species, and also moved the cpDNA boundary relative to that for nuclear markers. Biological traits, therefore, should also be considered when examining the genetic and ecological differentiation between closely related taxa

The Korean Baekdudaegan Mountains: A Glacial Refugium and a Biodiversity Hotspot That Needs to Be Conserved

The Baekdudaegan (BDDG; Figure 1) is a mountain range relatively unknown outside Korea. From recent times, however, the BDDG is known outside Korea because it shelters the small county of Pyeongchang, the venue of the 2018 Winter Olympic Games.This research was supported by Korea Research Foundation grants; KRF-2013R1A1A2063524 to MYC and NRF-2011-0017236, NRF-2013R1A1A3010892, and NRF-2017R1A2B4012215 to MGC and was carried out as part of the Infrastructure for the Conservation and Restoration of Rare and Endemic Plants in Korea National Arboretum that supported to MGC from 2015 to 2018.Peer reviewe

Phylogeography of the endangered orchids Cypripedium japonicum and Cypripedium formosanum in East Asia: Deep divergence at infra- and interspecific levels

To date, little is known about the past evolutionary trajectories of rare and endangered orchids native to mainland China, Japan, and Korea (the CJK region). In this study, we focus on two endangered orchids, Cypripedium japonicum (present in the three countries) and C. formosanum (endemic to Taiwan), to understand the divergence/speciation models that would have been operating in this group, including genetic diversity, geographic structure, and colonization pathways across the region. Using a combination of five cpDNA regions, we reconstructed phylogenetic trees and investigated the genetic diversity/structure of 20 populations. Ecological niche modeling was used to gain insight into the paleodistribution and dispersal corridors at the Last Glacial Maximum and to survey climatic niche differences. Populations from mainland China + Korea, Japan, and Taiwan formed three distinct monophyletic lineages and were placed into separate genetic clusters, agreeing with geographic barriers and species boundaries. Populations of C. japonicum in mainland China harbored the highest diversity, suggesting the presence of multiple glacial refugia. The Korean populations would have originated from either western/central or eastern China, probably using a dispersal corridor across the East China Sea shelf. The divergence of C. formosanum is proposed under an allopatric speciation model, also highly influenced by a climate niche shift. In the context of previous studies, a deep divergence in cpDNA sequences between Chinese + Korean and Japanese populations of C. japonicum may be taken as an example of the speciation events of the CJK flora since the late Neogene that have led to its current species richness.This study was supported by the Biodiversity Survey, Observation and Assessment Program of the Ministry of Ecology and Environment of China to HZT and by Basic Science Program through the National Research Foundation of Korea (NRF-2017R1A2B4012215) to MGC, and funded by the Ministry of Science and ICT of the Republic of Korea (NRF-2020R1I1A3074635) to MYC.INTRODUCTION MATERIALS AND METHODS Study species Population sampling DNA extraction cpDNA-PCR optimum primer selection cpDNA sequence alignment and assembly Haplotype distribution, phylogenetic analyses, and genetic diversity Genetic differentiation and structure Mismatch distribution analysis, neutrality detection, and demographic history ENM and population connectivity Niche comparisons in E-space RESULTS Haplotype distribution and phylogeny Genetic diversity Genetic differentiation and structure Mismatch distribution analysis, neutrality detection, and demographic history ENM and population connectivity Niche comparisons in E-space DISCUSSION Deep genetic and climatic divergence of Cypripedium sect. Flabellinervia in the CJK region: taxonomic considerations Haplotype and nucleotide diversity in Cypripedium sect. Flabellinervia: inference of glacial refugia and demographic history Origin of Korean populations of Cypripedium japonicum Origin of Cypripedium formosanum CONCLUSIONS AUTHOR CONTRIBUTIONS ACKNOWLEDGEMENTS Appendix 1: The cpDNA sequence information of Cypripedium sect. Flabellinervia deposited in the GenBank databas

Phylogeny and biogeography of Fagus (Fagaceae) based on 28 nuclear single/low-copy loci

Fagus L. is a key component in temperate deciduous broadleaf forests of the Northern Hemisphere. However, its biogeographic history has not been examined under the framework of a fully resolved and reasonably time-calibrated phylogeny. In this study, we sequenced 28 nuclear single/low-copy loci (18 555 bp in total) of 11 Fagus species/segregates and seven outgroups. Phylogenetic trees were reconstructed using both concatenation-based (maximum parsimony, maximum likelihood, and Bayesian inference) and coalescent-based methods (StarBEAST2, ASTRAL). The monophyly of two subgenera (Fagus and Engleriana) and most sections was well supported, except for sect. Lucida, which was paraphyletic with respect to sect. Longipetiolata. We also found a major phylogenetic conflict among North American, East Asian, and West Eurasian lineages of subgen. Fagus. Three segregates that have isolated distribution (F. mexicana, F. multinervis, and F. orientalis) were independent evolutionary units. Biogeographic analysis with fossils suggested that Fagus could have originated in the North Pacific region in late early Eocene. Major diversifications coincided with a climate aberration at the Eocene/Oligocene boundary and the global cooling since mid-Miocene. The late Miocene accelerated global cooling and the Pleistocene glaciations would have driven beeches into East Asia, North America, and West Eurasia. Meanwhile, range reduction and extinction in high latitudes, central Asia, and western North America converged to form the beech modern distribution pattern. This study provides a first attempt to disentangle the biogeographic history of beeches in the context of a nearly resolved and time-calibrated phylogeny, which could shed new insights into the formation of the temperate biome in the Northern Hemisphere.This work was supported by the National Natural Science Foundation of China (Grant Nos. 31770236, 30760016, and 31560064) and the Strategic Priority Research Program of Chinese Academy of Sciences (XDB31000000).1 Introduction 2 Material and Methods 2.1 Taxon sampling 2.2 Screening of nuclear single/low-copy orthologous locus 2.3 DNA extraction, PCR protocol, and sequencing 2.4 Phylogenetic analyses and molecular dating 2.5 Ancestral area reconstruction 3 Results 3.1 Concatenated tree 3.2 Species tree and molecular dating 3.3 Ancestral area reconstruction 4 Discussion 4.1 Nearly resolved and well supported phylogeny of Fagus 4.2 Species delimitation of three segregates within Fagus 4.3 Biogeographic history of beech species Acknowledgement