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1.
Genes (Basel) ; 15(3)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38540439

RESUMO

Corylopsis Siebold & Zucc. (Hamamelidaceae) is widely used as a horticultural plant and comprises approximately 25 species in East Asia. Molecular research is essential to distinguish Corylopsis species, which are morphologically similar. Molecular research has been conducted using a small number of genes but not in Corylopsis. Plastid genomes of Corylopsis species (Corylopsis gotoana, Corylopsis pauciflora, and Corylopsis sinensis) were sequenced using next-generation sequencing techniques. Repeats and nucleotide diversity that could be used as DNA markers were also investigated. A phylogenetic investigation was carried out using 79 protein-coding genes to infer the evolutionary relationships within the genus Corylopsis. By including new plastomes, the overall plastid genome structure of Corylopsis was similar. Simple sequence repeats of 73-106 SSRs were identified in the protein-coding genes of the plastid genomes, and 33-40 long repeat sequences were identified in the plastomes. The Pi value of the rpl33_rps18 region, an intergenic spacer, was the highest. Phylogenetic analysis demonstrated that Corylopsis is a monophyletic group and Loropetalum is closely related to Corylopsis. C. pauciflora, C. gotoana, and C. spicata formed a clade distributed in Japan, whereas C. sinensis, C. glandulifera, and C. velutina formed a clade that was distributed in China.


Assuntos
Genomas de Plastídeos , Hamamelidaceae , Filogenia , Evolução Biológica , Plastídeos/genética , Hamamelidaceae/genética
2.
Am J Bot ; 111(2): e16275, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38303667

RESUMO

PREMISE: Snow is an important environmental factor affecting plant distribution. Past changes in snowfall regimes may have controlled the demographies of snow-dependent plants. However, our knowledge of changes in the distribution and demographies of such plants is limited because of the lack of fossil records. METHODS: Population genetic and landscape genetic analyses were used to investigate the response of population dynamics of Arnica mallotopus (Asteraceae)-a plant confined to heavy-snow areas of Japan-to changes in snowfall regimes from the Last Glacial Period to the Holocene. RESULTS: The population genetic analysis suggested that the four geographic lineages diverged during the Last Glacial Period. The interaction between reduced snowfall and lower temperatures during this period likely triggered population isolation in separate refugia. Subpopulation differentiation in the northern group was lower than in the southern group. Our ecological niche model predicted that the current distribution was patchy in the southern region; that is, the populations were isolated by topologically flat and climatically unsuitable lowlands. The landscape genetic analysis suggested that areas with little snowfall acted as barriers to the Holocene expansion of species distribution and continued limiting gene flow between local populations. CONCLUSIONS: These findings indicate that postglacial population responses vary among regions and are controlled by environmental and geographic factors. Thus, changes in snowfall regime played a major role in shaping the distribution and genetic structure of the snow-dependent plant.


Assuntos
Arnica , Variação Genética , Japão , Neve , Dinâmica Populacional
3.
Sci Rep ; 14(1): 957, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200076

RESUMO

The Ryukyu Islands of Japan are a biodiversity hotspot due to geographical and historical factors. Tricyrtis formosana is a perennial herbaceous plant that commonly found in Taiwan. But only a few populations have been identified in a limited habitat on Iriomote Island, while populations of unknown origin occur near human settlements in an area on the main island of Okinawa. To better understand these populations of the phylogenetic uniqueness and intrinsic vulnerability, we conducted comparative analyses including (1) phylogeny and population structure with MIG-seq data, (2) photosynthesis-related traits of plants grown under common conditions and (3) transcriptome analysis to detect deleterious variations. Results revealed that T. formosana was split into two clades by the congeners and that Iriomote and Okinawa populations independently derived from ancestral Taiwanese populations in each clade. Photosynthetic efficiency was lowest in the Iriomote population, followed by Okinawa and Taiwan. Transcriptome analysis showed that the Iriomote population accumulated more deleterious variations, suggesting intrinsic vulnerability. These results indicate that each T. formosana population in Japan is phylogenetically unique and has been independently dispersed from Taiwan, and that the Iriomote population presents a high conservation difficulty with a unique photosynthesis-related characteristic and a larger amount of deleterious variations.


Assuntos
Espécies em Perigo de Extinção , Genética Populacional , Liliaceae , Biodiversidade , Japão , Liliaceae/genética , Filogenia , Conservação dos Recursos Naturais , Fotossíntese
4.
Genes Genet Syst ; 97(2): 93-99, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35545526

RESUMO

Interspecific hybridization is a critical issue in conservation biology because it may drive small populations to extinction through direct or indirect processes. In this study, to develop a conservation strategy for an endangered rear-edge population of Carex podogyna in Ashiu, Kyoto, Japan, we performed a molecular genetic analysis of the wild population and an ex-situ population established from wild seeds. Microsatellite genotypic data revealed a complete loss of genetic diversity in the wild population, suggesting that it has long been prone to genetic drift due to isolation as a small population. In contrast, microsatellite analysis of 13 ex-situ individuals detected multiple alleles that are not harbored in the wild C. podogyna population. Sequence analysis revealed that these individuals are likely natural hybrids between C. podogyna and a co-occurring species, C. curvicollis, although established hybrids have never been found in the natural habitat. Based on our observation of variegated leaves in hybrid individuals, we propose that hybrids have been excluded by natural selection and/or interspecific competition caused by insufficient productivity of photosynthesis, although other genetic and ecological factors may also be influential. Overall, this study indicates that natural mechanisms selectively removing the hybrids have maintained the genetic purity of this rear-edge population of C. podogyna, and also emphasizes the importance of genetic assessment in ex-situ conservation programs.


Assuntos
Carex (Planta) , Cyperaceae , Carex (Planta)/genética , Cyperaceae/genética , Variação Genética , Genótipo , Humanos , Hibridização Genética , Repetições de Microssatélites
5.
PLoS One ; 16(12): e0261600, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34905587

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0252581.].

6.
AoB Plants ; 13(4): plab039, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34285794

RESUMO

Flowering is an important step in the life cycle of plants and indicates adaptability to external climatic cues such as temperature and photoperiod. We investigated the expression patterns of core genes related to flowering-time regulation in Japanese wild radish (Raphanus sativus var. raphanistroides) with different vernalization requirements (obligate and facultative) and further identified climatic cues that may act as natural selective forces. Specifically, we analysed flowering-time variation under different cold and photoperiod treatments in Japanese wild radish collected from the Hokkaido (northern lineage) and Okinawa (southern lineage) islands, which experience contrasting climatic cues. The cultivation experiment verified the obligate and facultative vernalization requirements of the northern and southern wild radish accessions, respectively. The expression of major genes involved in flowering time indicated that RsFLC and RsCOL5 (A&B) may interact to regulate flowering time. Notably, floral initiation in the northern lineage was strongly correlated with RsFLC expression, whereas flowering in the southern linage was correlated with induction of RsCOL5-A expression, despite high RsFLC transcript levels. These results suggested that the northern accessions are more sensitive to prolonged cold exposure, whereas the southern accessions are more sensitive to photoperiod. These different mechanisms ultimately confer an optimal flowering time in natural populations in response to locally contrasting climatic cues. This study provides new insights into the variant mechanisms underlying floral pathways in Japanese wild radish from different geographic locations.

7.
PLoS One ; 16(6): e0252581, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34097720

RESUMO

Earlier phylogenetic studies in the genus Pinguicua (Lentibulariaceae) suggested that the species within a geographical region was rather monophyletic, although the sampling was limited or was restricted to specific regions. Those results conflicted with the floral morphology-based classification, which has been widely accepted to date. In the current study, one nuclear ribosomal DNA (internal transcribed spacer; ITS) and two regions of chloroplast DNA (matK and rpl32-trnL), from up to ca. 80% of the taxa in the genus Pinguicula, covering all three subgenera, were sequenced to demonstrate the inconsistency and explore a possible evolutionary history of the genus. Some incongruence was observed between nuclear and chloroplast topologies and the results from each of the three DNA analyses conflicted with the morphology-based subgeneric divisions. Both the ITS tree and network, however, corresponded with the biogeographical patterns of the genus supported by life-forms (winter rosette or hibernaculum formation) and basic chromosome numbers (haploidy). The dormant strategy evolved in a specific geographical region is a phylogenetic constraint and a synapomorphic characteristic within a lineage. Therefore, the results denied the idea that the Mexican group, morphologically divided into the three subgenera, independently acquired winter rosette formations. Topological incongruence among the trees or reticulations, indicated by parallel edges in phylogenetic networks, implied that some taxa originated by introgressive hybridisation. Although there are exceptions, species within the same geographical region arose from a common ancestor. Therefore, the classification by the floral characteristics is rather unreliable. The results obtained from this study suggest that evolution within the genus Pinguicula has involved; 1) ancient expansions to geographical regions with gene flow and subsequent vicariance with genetic drift, 2) acquirement of a common dormant strategy within a specific lineage to adapt a local climate (i.e., synapomorphic characteristic), 3) recent speciation in a short time span linked to introgressive hybridisation or multiplying the ploidy level (i.e., divergence), and 4) parallel evolution in floral traits among lineages found in different geographical regions (i.e., convergence). As such, the floral morphology masks and obscures the phylogenetic relationships among species in the genus.


Assuntos
Lamiales/classificação , Núcleo Celular/genética , Cloroplastos/genética , DNA de Cloroplastos/classificação , DNA de Cloroplastos/genética , DNA de Cloroplastos/metabolismo , DNA de Plantas/classificação , DNA de Plantas/genética , DNA de Plantas/metabolismo , Evolução Molecular , Geografia , Lamiales/anatomia & histologia , Lamiales/genética , Filogenia , Folhas de Planta/genética
8.
Mol Phylogenet Evol ; 163: 107230, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34133947

RESUMO

Phenotypic polymorphism within a species is a notable phenomenon in evolutionary biology to understand the process of adaptive speciation and other historical events. The Saxifraga fortunei complex is a widespread herb found in East Asia. It includes several ecotypic taxa corresponding to their habitat environments. The distribution of the various ecotypes in a limited area of the Japanese Archipelago makes the species a suitable model to investigate the impact of population demographic history and natural selection on lineage diversification. Here, Sanger-based sequencing was used to estimate the divergence timeframe between populations of the Eurasian continent and Japan. Genome-wide SNPs obtained by ddRAD sequencing were used to investigate the phylogeographic origins of ecotypic taxa. The phylogenetic analyses revealed the divergence of the Japanese population from the continental population in the late Miocene. Two distinct regional clades of North and South Japan were identified; phenotypic diversification was evident only in the southern clade. The South Japan clades displayed a historical distribution expansion from north to south. The phenotypic variations appeared to have generated during the expansion. The ecotypic boundaries were incongruent with the genetic grouping. We propose that morphological and ecological specialization in Japanese populations was repeatedly generated by local natural selection.


Assuntos
Saxifragaceae , Ecossistema , Japão , Filogenia , Filogeografia
9.
Genes Genet Syst ; 96(3): 159-164, 2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34148896

RESUMO

Arnica mallotopus is a perennial herb endemic to the snowy regions of Japan. At the southern edge of its distribution, in Kyoto Prefecture, overgrazing by sika deer and decreased snowfall have resulted in the rapid decline of A. mallotopus populations. Therefore, there is an urgent need for a conservation genetic analysis of the remaining local populations. In this study, we first developed 13 EST-SSR markers to evaluate genetic variation in A. mallotopus. The average number of alleles per locus was 5.33. Genetic analysis using these markers showed that the investigated samples were classified into two groups corresponding to landscape structure. One group isolated from a tributary of the Yura River showed a strong population bottleneck signal, likely resulting from founder effects and subsequent drifts. On the other hand, the genetic diversity of the second group in the main distribution along the Yura River was higher and less inbred. Overall, our assessment suggested recognizing the two genetic groups as management units in conservation programs for the threatened populations.


Assuntos
Arnica , Asteraceae , Cervos , Animais , Cervos/genética , Etiquetas de Sequências Expressas , Variação Genética , Repetições de Microssatélites
10.
Ann Bot ; 128(3): 343-356, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34104952

RESUMO

BACKGROUND AND AIMS: Hybridization is the main driver of plant diversification, and gene flow via hybridization has multifaceted effects on plant evolution. Carex angustisquama is an extremophyte that grows on soils heavily acidified by volcanism. Despite its habitat distinct from that of other species, this species is known to form interspecific hybrids, implying interspecific gene flow. It is crucial to verify the extent and direction of interspecific gene flow between C. angustisquama and closely related species to understand the evolutionary process of an extremophyte in solfatara fields. METHODS: In this study, expressed sequence tag-simple sequence repeat markers were utilized to infer the extent and direction of interspecific gene flow between C. angustisquama and closely related species. KEY RESULTS: Bayesian clustering and simulation analyses revealed that all individuals of the three hybrid species were classified into the first hybrid generation or first backcross to C. angustisquama; therefore, current interspecific gene flow is limited. Moreover, in the Bayesian inference of historical gene flow based on multispecies samples, the model that assumed no interspecific gene flow was the most strongly supported across all species pairs, including phylogenetically close but ecologically distinctive species pairs. CONCLUSIONS: Our results revealed that interspecific gene flow between C. angustisquama and its related species has been limited both currently and historically. Moreover, our results of Bayesian inference of historical gene flow indicated that extrinsic, rather than intrinsic, factors probably act as isolating barriers between Carex species, with hybrid breakdown via microhabitat segregation being the probable potential barrier. Overall, our findings provide insights into the evolutionary process of an extremophyte in solfatara fields and offer an important example of the mechanisms of diversification of the speciose genus Carex.


Assuntos
Carex (Planta) , Cyperaceae , Teorema de Bayes , Hibridização Genética , Filogenia
11.
Am J Bot ; 108(4): 680-693, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33881773

RESUMO

PREMISE: The genetic structure between plant populations is facilitated by the spatial population arrangement and limited dispersal of seed and pollen. Saxifraga acerifolia, a local endemic species in Japan, is a habitat specialist that is confined to waterfalls in riparian environments. Its sister species, Saxifraga fortunei, is a generalist that is widely distributed along riverbanks. Here, we examined sympatric populations of the two Saxifraga species to test whether the differences in habitat preference and colonization process influenced regional and local genetic structures. METHODS: To reveal genetic structures, we examined chloroplast microsatellite variations and genome-wide nucleotide polymorphisms obtained by genotyping by sequencing. We also estimated the gene flow among and within populations and performed landscape genetic analyses to evaluate seed and pollen movement and the extent of genetic isolation related to geographic distance and/or habitat differences. RESULTS: We found strong genetic structure in the specialist S. acerifolia, even on a small spatial scale (<1 km part); each population on a different waterfall in one river system had a completely different predominant haplotype. By contrast, the generalist S. fortunei showed no clear genetic differentiation. CONCLUSIONS: Our findings suggest that the level of genetic isolation was increased in S. acerifolia by the spatially fragmented habitat and limited seed and pollen dispersal over waterfalls. Habitat differentiation between the sister taxa could have contributed to the different patterns of gene flow and then shaped the contrasting genetic structures.


Assuntos
Variação Genética , Saxifragaceae , Ecossistema , Fluxo Gênico , Genética Populacional , Japão , Repetições de Microssatélites/genética , Saxifragaceae/genética , Simpatria
12.
Heredity (Edinb) ; 126(4): 615-629, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33510468

RESUMO

Climate relicts hold considerable importance because they have resulted from numerous historical changes. However, there are major interspecific variations among the ways by which they survived climate changes. Therefore, investigating the factors and timing that affected population demographics can expand our understanding of how climate relicts responded to historical environmental changes. Here, we examined herbaceous hydrangeas of genus Deinanthe in East Asia, which show limited distributions and a remarkable disjunction between Japan and central China. Chloroplast genome and restriction site-associated DNA sequencing revealed that speciation event occurred in the late Miocene (ca. 7-9 Mya) in response to global climate change. Two lineages apparently remained not branched until the middle Quaternary, and afterwards started to diverge to regional population groups. The narrow endemic species in central China showed lower genetic diversity (He = 0.082), as its population size rapidly decreased during the Holocene due to isolation in montane refugia. Insular populations in the three Japanese islands (He = 0.137-0.160) showed a genetic structure that was inconsistent with sea barriers, indicating that it was shaped in the glacial period when its range retreated to coastal refugia on the exposed sea floor. Demographic modelling by stairway-plot analysis reconstructed variable responses of Japanese populations: some experienced glacial bottlenecks in refugial isolation, while post-glacial range expansion seemingly exerted founder effects on other populations. Overall, this study demonstrated the involvement of not just one, but multiple factors, such as the interplay between climate changes, geography, and other population-specific factors, that determine the demographics of climate relicts.


Assuntos
Mudança Climática , Hydrangea , Variação Genética , Filogenia , Filogeografia , Refúgio de Vida Selvagem , Análise de Sequência de DNA
13.
FEMS Microbiol Ecol ; 96(12)2020 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-33016310

RESUMO

Variation in partner quality is commonly observed in diverse cooperative relationships, despite the theoretical prediction that selection favoring high-quality partners should eliminate such variation. Here, we investigated how genetic variation in partner quality could be maintained in the nitrogen-fixing mutualism between Lotus japonicus and Mesorhizobium bacteria. We reconstructed de novo assembled full-genome sequences from nine rhizobial symbionts, finding massive variation in the core genome and the similar symbiotic islands, indicating recent horizontal gene transfer (HGT) of the symbiosis islands into diverse Mesorhizobium lineages. A cross-inoculation experiment using 9 sequenced rhizobial symbionts and 15 L. japonicus accessions revealed extensive quality variation represented by plant growth phenotypes, including genotype-by-genotype interactions. Variation in quality was not associated with the presence/absence variation in known symbiosis-related genes in the symbiosis island; rather, it showed significant correlation with the core genome variation. Given the recurrent HGT of the symbiosis islands into diverse Mesorhizobium strains, local Mesorhizobium communities could serve as a major source of variation for core genomes, which might prevent variation in partner quality from fixing, even in the presence of selection favoring high-quality partners. These findings highlight the novel role of HGT of symbiosis islands in maintaining partner quality variation in the legume-rhizobia symbiosis.


Assuntos
Lotus , Mesorhizobium , Rhizobium , Genômica , Mesorhizobium/genética , Rhizobium/genética , Simbiose
14.
Heredity (Edinb) ; 124(1): 93-107, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253956

RESUMO

Climatic perturbation during the Pleistocene era has played a major role in plant evolutionary history by altering species distribution range. However, the relative roles of climatic and geographic factors in the distribution dynamics remain poorly understood; in particular, the edaphic endemics. In this paper, we examine the evolutionary history of two ultramafic primroses, Primula hidakana and Primula takedana. These species are ecologically and morphologically distinct with disjunct distributions on Hokkaido Island, Japan. Primula hidakana is found on various rocks in southern Hokkaido and P. takedana in serpentine areas in northern Hokkaido. We performed population genetics analyses on nuclear and chloroplast data sets and tested alternative phylogenetic models of divergence using approximate Bayesian computation (ABC) analyses. Nuclear microsatellite loci clearly distinguished the two sister taxa. In contrast, chloroplast sequence variations were shared between P. takedana and P. hidakana. ABC analyses based on nuclear data supported a secondary contact scenario involving asymmetrical gene flow from P. hidakana to P. takedana. Paleodistribution modeling also supported the divergence model, and predicted their latitudinal range shifts leading to past secondary contact. Our findings highlight the importance of the distribution dynamics during the Pleistocene climatic oscillations in the evolution of serpentine plants, and demonstrate that tight species cohesion between serpentine and nonserpentine sister taxa has been maintained despite past interspecific gene flow across soil boundaries.


Assuntos
Mudança Climática , Especiação Genética , Genética Populacional , Primula/genética , Teorema de Bayes , Núcleo Celular/genética , DNA de Cloroplastos/genética , DNA de Plantas/genética , Ecossistema , Fluxo Gênico , Haplótipos , Ilhas , Japão , Repetições de Microssatélites , Modelos Genéticos , Filogenia
15.
Mol Ecol ; 29(17): 3234-3247, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31800130

RESUMO

Edaphic specialization is one of the main drivers of plant diversification and has multifaceted effects on population dynamics. Carex angustisquama is a sedge plant growing only on heavily acidified soil in solfatara fields, where only extremophytes can survive. Because of the lack of closely related species in similar habitats and its disjunct distribution, the species offers ideal settings to investigate the effects of adaptation to solfatara fields and of historical biogeography on the genetic consequences of plant edaphic specialization to solfatara fields. Here, genome-wide single nucleotide polymorphisms were used to reveal the phylogenetic origin of C. angustisquama, and 16 expressed sequence tag-simple sequence repeat markers were employed to infer population demography of C angustisquama. Molecular phylogenetic analysis strongly indicated that C. angustisquama formed a monophyletic clade with Carex doenitzii, a species growing on nonacidified soil in the sympatric subalpine zone. The result of population genetic analysis showed that C. angustisquama has much lower genetic diversity than the sister species, and notably, all 16 loci were completely homozygous in most individuals of C. angustisquama. Approximate Bayesian computation analysis supported the model that assumed hierarchical declines of population size through its evolutionary sequence. We propose that the edaphic specialist in solfatara fields has newly attained the adaptation to solfatara fields in the process of speciation. Furthermore, we found evidence of a drastic reduction in genetic diversity in C. angustisquama, suggesting that the repeated founder effects associated with edaphic specialization and subsequent population demography lead to the loss of genetic diversity of this extremophyte in solfatara fields.


Assuntos
Carex (Planta)/genética , Genética Populacional , Filogenia , Teorema de Bayes , Etiquetas de Sequências Expressas , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , Enxofre
16.
Appl Plant Sci ; 7(7): e11275, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31346507

RESUMO

PREMISE: Saxifraga fortunei (Saxifragaceae) includes several infraspecific taxa that are ecologically and morphologically distinct. To investigate the evolutionary history of phenotypic polymorphisms in this species, we developed expressed sequence tag-simple sequence repeat (EST-SSR) markers for S. fortunei. METHODS AND RESULTS: We developed 26 polymorphic markers based on transcriptome data obtained from Illumina HiSeq 2000. Within three populations of S. fortunei var. incisolobata, the number of alleles ranged from four to 25, and the levels of observed and expected heterozygosity ranged from 0.200 to 0.847 and from 0.209 to 0.930, respectively. Furthermore, all 26 loci showed transferability for S. fortunei var. obtusocuneata and S. fortunei var. suwoensis, and 18 loci were also successfully amplified in S. acerifolia. CONCLUSIONS: These newly developed EST-SSR markers will prove useful to infer the evolutionary history of S. fortunei var. incisolobata and its relatives in population genetic studies.

17.
Mol Phylogenet Evol ; 137: 146-155, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31075504

RESUMO

Clinal variation is a major pattern of observed phenotypic diversity and identifying underlying demographic processes is a necessary step to understand the establishment of clinal variation. The wild ginger series Sakawanum (genus Asarum) comprises four taxa, which exhibit intertaxonomic clinal variation in calyx lobe length across two continental islands isolated by a sea strait. To test alternative hypotheses of the evolutionary history and to determine the implications for the formation of clinal variation, we conducted approximate Bayesian computation (ABC) analysis and ecological niche modeling (ENM). ABC analysis indicated that the scenario assuming multiple admixture events was strongly supported. This scenario assumed two admixture events occurred between morphologically distinct taxa, likely leading to the generation of intermediate taxa. One of the admixture events was estimated to have occurred during the last glacial maximum (LGM), during which the taxa were estimated to have formed a common refugia in southern areas by ENM analysis. Although four taxa are currently distributed allopatrically on different islands and trans-oceanic dispersal appears unlikely, the formation of a land bridge and the geographic range shift to refugia would have allowed secondary contact between previously isolated taxa. This study suggests that clinal variation can be shaped by demographic history including multiple admixtures due to climatic oscillations.


Assuntos
Asarum/classificação , Asarum/genética , Sequência de Bases , Teorema de Bayes , Cloroplastos/genética , Ecossistema , Variação Genética , Haplótipos/genética , Repetições de Microssatélites/genética , Modelos Genéticos , Filogenia , Filogeografia , Probabilidade
18.
Mol Plant Microbe Interact ; 32(9): 1110-1120, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30880586

RESUMO

To investigate the genetic diversity and understand the process of horizontal gene transfer (HGT) in nodule bacteria associated with Lotus japonicus, we analyzed sequences of three housekeeping and five symbiotic genes using samples from a geographically wide range in Japan. A phylogenetic analysis of the housekeeping genes indicated that L. japonicus in natural environments was associated with diverse lineages of Mesorhizobium spp., whereas the sequences of symbiotic genes were highly similar between strains, resulting in remarkably low nucleotide diversity at both synonymous and nonsynonymous sites. Guanine-cytosine content values were lower in symbiotic genes, and relative frequencies of recombination between symbiotic genes were also lower than those between housekeeping genes. An analysis of molecular variance showed significant genetic differentiation among populations in both symbiotic and housekeeping genes. These results confirm that the Mesorhizobium genes required for symbiosis with L. japonicus behave as a genomic island (i.e., a symbiosis island) and suggest that this island has spread into diverse genomic backgrounds of Mesorhizobium via HGT events in natural environments. Furthermore, our data compilation revealed that the genetic diversity of symbiotic genes in L. japonicus-associated symbionts was among the lowest compared with reports of other species, which may be related to the recent population expansion proposed in Japanese populations of L. japonicus.


Assuntos
Transferência Genética Horizontal , Variação Genética , Lotus , Mesorhizobium , Nódulos Radiculares de Plantas , Lotus/microbiologia , Mesorhizobium/classificação , Mesorhizobium/genética , Filogenia , Nódulos Radiculares de Plantas/microbiologia , Simbiose/genética
19.
Appl Plant Sci ; 6(10): e01185, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30386711

RESUMO

PREMISE OF THE STUDY: Expressed sequence tag-simple sequence repeat (EST-SSR) markers were developed for Carex angustisquama (Cyperaceae) to investigate the evolutionary history of this plant that is endemic to solfatara fields in northern Japan. METHODS AND RESULTS: Using RNA-Seq data generated by the Illumina HiSeq 2000, 20 EST-SSR markers were developed. Polymorphisms were assessed in C. angustisquama and the closely related species C. doenitzii and C. podogyna. In C. angustisquama, many loci were monomorphic within populations; the average number of alleles ranged from one to five, and levels of expected heterozygosity ranged from 0.000 to 0.580, while all markers were polymorphic in a population of C. doenitzii. This indicates that low genetic polymorphism of C. angustisquama is likely due to the species' population dynamics, rather than to null alleles at the developed markers. CONCLUSIONS: These markers will be used to assess genetic diversity and structure and to investigate evolutionary history in future studies of C. angustisquama and related species.

20.
Plant Divers ; 40(1): 41-44, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30159540

RESUMO

Primula reinii (Primulaceae), a perennial herb belonging to the Primula section Reinii, occurs on wet, shaded rocky cliffs in the mountains of Japan. This threatened species comprises four varieties; these plants are very localized and rare in the wild. In this study, 43 microsatellite markers were developed using MiSeq sequencing to facilitate conservation genetics of these critically endangered primroses. We developed novel microsatellite markers for three varieties of P. reinii, and tested its polymorphism and genetic diversity using natural populations. These novel markers displayed relatively high polymorphism; the number of alleles and expected heterozygosities ranged from 2 to 6 (mean = 3.2) and 0.13 to 0.82 (mean = 0.45), respectively. All loci were in Hardy-Weinberg equilibrium. These microsatellite markers will be powerful tools to assess P. reinii genetic diversity and develop effective conservation and management strategies.

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