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1.
We sequenced the nuclear ribosomal internal transcribed spacer (ITS) regions to determined the phylogenetic relationships of the severalGoodyera species in Korea and to measure the extent of their differentiation region. ITS 1 was 238 to 239 bp long while ITS 2 was 258 to 259 bp. The 5.8S coding region was 156 bp long. Sequence divergences among species, calculated by Kimura’s two- parameter method, ranged from 0.0 to 5.4%. The most parsimonious tree, with a consistency index of 0.935 and a retention index of 0.937, was produced with 337 steps. Our ITS sequence results demonstrate the monophyly of KoreanGoodyera and support previous morphological, geographical, and RAPD data analyses.  相似文献   

2.
The systematics ofScleromitrula andVerpatinia of the family Sclerotiniaceae is reevaluated on the basis of morphological, cultural and molecular criteria.Scleromitrula shiraiana, Verpatinia species andCiborinia candolleana share gross morphological, microanatomical and cultural features which clearly distinguish them from the closely relatedCiborinia andRutstroemia species. Phylogenetic analyses of sequences from the internal transcribed spacer region (ITS1, ITS2, and the 5.8S gene) of nuclear ribosomal DNA demonstrate that the stipitate-capitate specimens ofScleromitrula andVerpatinia species plus the stipitate-cupulateCiborinia candolleana constitute a monophyletic clade separate from a clade including the type species ofCiborinia. Scleromitrula is emended to includeS. shiraiana, the new speciesS. rubicola, C. candolleana, and specimens formerly assigned toVerpatinia. A key to the accepted species ofScleromitrula is provided.  相似文献   

3.
We examined the phylogeny of the genusRubus in Korea using an internal transcribed spacer (ITS) of the nuclear ribosomal DNA and a trnL-trnF (trnL/F) intergenic region of the chloroplast DNA. In all, 21 ingroup species (1.2 kb for each species) were analyzed using parsimony, resulting in 672 aligned sequences from ITS, and 502 bases with trnL/F. Individual and combined analysis of ITS and trnL/F data proved that the genusRubus is a monophyletic group. This phylogeny also substantiated a previous sectional classification scheme rather than a subgerius classification scheme. However, our results did not support the earlier sectional classification by Focke (sect.Corchorifolii), but did support the sectional classification of Nakai: sect.Crataegifolii (R. crataegifolius, R. takesimensis andR. trifidus), and sect.Villosii (R. corchorifolius). Most of these species, which are found in Korea and belong to subg.Idaeobatus, appeared in two different groups in all data sets. This suggests that this subgenus is a polyphyletic group that has gone through at least two independent evolutionary processes. The taxa, when mapped onto the combined tree, showed that the occurrence of their morphological characters of simple and compound leaves was concurrent in KoreanRubus. ITS sequence data were consistent overall with the geographical distribution of each species. Furthermore, the trnL/F sequence data provided phylogenetic information within closely related species.  相似文献   

4.
To better understand the patterns of variability and distributions ofHemerocallis in Korea, 53 locations were visited and measurements of 19 morphological and phenological characters were taken on plants directly from their natural habitats. For morphometric analysis, 10 plants from each of 34 populations and five herbarium specimens ofH. middendorffii were used and the data from 12 quantitative characters was analyzed using univariate analysis. Except the littoral populations of Cheju, Hong, Taehuksan, and Sohuksan Islands (H. hongdoensis M. Chung & S. Kang), three peninsular KoreanHemerocallis species can be recognized mainly in South Korea:H. hakuunensis Nakai (=H. micrantha Nakai, growing on southern, central, and northwestern Korea);H. thunbergii Baker (=H. coreana Nakai, found on southeastern and central Korea); andH. middendorffii Tr. et Mey. (central and northeastern Korea). Morphological and phenological features contributing to recognition of the three groups were; color of perianth, shape of roots, shape of inflorescence, flowering time, odor, length of inflorescence, width of the lowest bracts, length of perianth tube enclosing a ovary, width of the inner perianth lobes. Natural hybridization seems to be rare in KoreanHemerocallis. It appears that the KoreanHemerocallis species are relatively well characterized by their distribution patterns, phenology, and habitats compared with the JapaneseHemerocallis species.  相似文献   

5.
As part of our ongoing phylogenetic study of genusHypericum, nuclear ribosomal DNA internal transcribed spacer sequences were analyzed for 36 species ofHypericum as ingroup and two species ofThornea as outgroup. This sampling included most of the previously described species from both Korea and Japan. The ITS phylogeny suggested that the surveyedHypericum species belong to a monophyletic section,Trigynobrathys, and a polyphyletic section,Hypericum. In addition, two monotypic sections,Sampsonia andRoscyna, were identified. Members of sectionHypericum occur in four different lineages worldwide, which imply at least four independent origins. The Korean and Japanese species of sectionHypericum form a monophyletic group, except forH. vulcanicum. Instead, that particular species belongs to a distinct monophyletic group withH. scoreri andH. formosa from other geographic areas, and is a sister to sectionTrigynobrathys. The Korean and Japanese species of sectionTrigynobrathys show a monophyletic origin.H. sampsonii is now recognized as a distinct section rather than being a member of sectionsHypericum orDrosocarpium, as had been indicated previously. Our results differ somewhat from those of recent morphological and cytological studies. The phylogenetic relationships among Korean and Japanese species have now been mostly resolved via ITS phylogeny.  相似文献   

6.
ITS regions (internal transcribed spacers—ITS1 andITS2—with the 5.8S gene of the nuclear rDNA) of 25 fruit body samples ofTerfezia terfezioides, originating from Hungary and Italy, were compared. The amplification and sequencing of the ITS region was successful with both theITS1-ITS4 andITSIF-ITS4 primer pairs. No differences of the restriction fragment length polymorphism profiles were detected among 19 samples collected in one place at the same time. The sequences of the ITS region of 9 samples collected in different localities were highly invariable, differing in only two bases. Thus the intraspecific homogeneity of the ITS region seems to be an important species-specific characteristic ofT. terfezioides in contrast to otherTerfezia species. As the samples of the species were collected from different and distant localities of Europe, the ITS sequence ofT. terfezioides can be considered a very conservative, reliable molecular marker of the fungus. *** DIRECT SUPPORT *** A00EN076 00008  相似文献   

7.
A basidiomyetous yeast strain RO-203, which formed orange-red colored colonies, was isolated from a sample of paddy rice crops at the ripe stage in Japan. Morphological, physiological and biochemical characterization indicated that this strain belonged to the genus Rhodotorula. Molecular taxonomic analysis based on the 26S rDNA D1/D2 domain and internal transcribed spacer (ITS) region sequences showed that RO-203 represents an undescribed yeast species, for which the name Rhodotorula oryzae sp. nov. is proposed (type strain: AS 2.2363T = MAFF 516128T). The new species clustered in a branch together with Sakaguchia dacryoidea in phylogenetic trees based on the D1/D2 and ITS sequences. These two species differed by 2.3% and 12% nucleotide divergences in the D1/D2 and ITS regions, respectively.  相似文献   

8.
The 3′ region of the external transcribed spacer (ETS) of 18S–26S nuclear ribosomal DNA was sequenced in 19 representatives ofCalycadenia/Osmadeniaand two outgroup species (Compositae) to assess its utility for phylogeny reconstruction compared to rDNA internal transcribed spacer (ITS) data. Universal primers based on plant, fungal, and animal sequences were designed to amplify the intergenic spacer (IGS) and an angiosperm primer was constructed to sequence the 3′ end of the ETS in members of tribe Heliantheae. Based on these sequences, an internal ETS primer useful across Heliantheaesensu latowas designed to amplify and sequence directly the 3′ ETS region in the study taxa, which were the subjects of an earlier phylogenetic investigation based on ITS sequences. Size variation in the amplified ETS region varied across taxa of Heliantheaesensu latofrom approximately 350 to 700 bp, in part attributable to an approximately 200-bp tandem duplication in a common ancestor ofCalycadenia/Osmadenia.Phylogenetic analysis of the 200-bp subrepeats and examination of apomorphic changes in the duplicated region demonstrate that the subrepeats inCalycadenia/Osmadeniahave evolved divergently. Phylogenetic analyses of the entire amplified ETS region yielded a highly resolved strict consensus tree that is nearly identical in topology to the ITS tree, with strong bootstrap and decay support on most branches. Parsimony analyses of combined ETS and ITS data yielded a strict consensus tree that is better resolved and generally better supported than trees based on either data set analyzed separately. We calculated an approximately 1.3- to 2.4-fold higher rate of sequence evolution by nucleotide substitution in the ETS region studied than in ITS-1 + ITS-2. A similar disparity in the proportion of variable (1.3 ETS:1 ITS) and potentially informative (1.5 ETS:1 ITS) sites was observed for the ingroup. Levels of homoplasy are similar in the ETS and ITS data. We conclude that the ETS holds great promise for augmenting ITS data for phylogenetic studies of young lineages.  相似文献   

9.
Fusarium species causing wilt diseases in different plants were characterised by comparing nonpathogenic and different pathogenic species using rDNA RFLP analysis. The ITS (internal transcribed spacer) region of 12 isolates belonging to the section Elegans, Laseola, Mortiella, Discolor, Gibbosum, Lateritium and Sporotrichiella were amplified by universal ITS primers (ITS-1 and ITS-4) using polymerase chain reaction (PCR). Amplified products, which ranged from 522 to 565 bp were obtained from all 12 Fusarium isolates. The amplified products were digested with seven restriction enzymes, and restriction fragment length polymorphism (RFLP) patterns were analysed. A dendrogram derived from PCR-RFLP analysis of the rDNA region divided the Fusarium isolates into three major groups. Assessment of molecular variability based on rDNA RFLP clearly indicated that Fusarium species are heterogeneous and most of the forma speciales have close evolutionary relationships.  相似文献   

10.
The results of a pilot DNA sequencing study of cycads conducted at the new molecular systematics laboratory at Fairchild Tropical Garden are presented and assessed with reference to previous phylogenetic analyses and classification schemes based on morphology and anatomy. Two DNA regions were sequenced and analyzed for variation, an intron in the trriL gene in the chloroplast genome (trriL intron) and the internal transcribed spacer region between the 5.8S and 26S ribosomal DNA subunits (ITS2). The trnL intron proved to be relatively conservative among cycad genera, while the ITS2 region contained higher levels of variation. Parsimony analysis of the sequences suggests a number of relationships, some of which were inferred by previous morphological studies, some of which are new. The sequences ofCycas are the most divergent among cycads, suggesting the longest isolation.Dioon is relatively isolated from the other genera and contains two major clades.Stangeria does not appear closely related toBowenia but does seem to have a weak affinity withZamia andMicrocycas. Lepidozamia is more closely related toEncephalartos than toMacrozamia. Sequence variation among the species ofCeratozamia is low.Microcycas andZamia are closely related.  相似文献   

11.
Molecular diagnosis is highly valuable for the species identification of microscopic mites. Here, we collected some economically important mites of the superfamily Acaroidea from various stored products in Korea. Those nucleotide sequences of ribosomal second internal transcribed spacer (ITS2) and the mitochondrial cytochrome oxidase subunit I (COI) regions were determined by PCR using universial primers. In nucleotide sequence comparison at GenBank database, seven species including Rhizoglyphus robini, R. echinopus, Sancassania sp. Acarus siro, Tyrophagus putrescentiae, T. similis in Acaridae and Suidasia medanensis in Suidasiidae were identified. Particularly, COI sequences of R. robini, R. echinopus, Sancassania sp. and T. similis were firstly determined. Our results suggest that the phylogenetic relationships inferred from the ITS2 region, rather than COI region, were similar to those derived based on their morphological classification. Our study provides molecular information for the identification and phylogenetic relationship of acaroid mites in Korea.  相似文献   

12.
The internal transcribed spacer (ITS) regions of 18–26S nuclear ribosomal DNA was sequenced to address phylogenetic relationships and to measure the extent of differentiation among six species of the Far EasternIndigofera. ITS 1 had 230–240 base pairs (bp) long while ITS 2 had 211–213 bp long. The 5.8S rRNA coding region was 161 bp long. Sequence divergence calculated by Kimura's two parameter method between species ranged from 0.00 to 13.49%. A single most parsimonious tree was produced from 77 variable nucleotide sites, which had a consistency index of 0.97 and a retention index of 0.83. ITS sequence data suggested that the continental species ofI. kirilowii (2n=16) is diverged from the common ancestor of other species at first, and then the island species ofI. decora (2n=48) andI. venulosa and the Korean Peninsular species ofI. grandiflora (2n=16) andI. koreana (2n=32) are diverged from the ancestor. The molecular data supports that the speciation in the Far EasternIndigofera occurred with polyploidization from continental ancestor to peripheral peninsular and island species.  相似文献   

13.
14.
Tybrind Vig is a late Mesolithic (Ertebølle) coastal settlement, dated to the period 5600–4000 BC. The site has yielded some very important finds associated with fishing activity, probably the best preserved example from the Mesolithic in Europe. Recently analysed botanical samples from submerged cultural deposits have provided evidence for the contribution of plants to the subsistence diet of the inhabitants of Tybrind Vig. The food plant remains are represented by the charred fragments of parenchymatous tissue from roots ofBeta vulgaris ssp.maritima (sea beet), fragments ofQuercus sp. parenchyma (acorn), and shell fragments ofCorylus avellana (hazelnut). The possibility that the grains ofGlyceria fluitans (floating sweet grass) and stems ofPhragmites australis (reed) were collected for food should not be excluded. In addition to the species identified in the charred remains, an abundance of edible plant seeds and fruits were represented in the waterlogged remains, suggesting that a much broader range of food plants was available in the area. These additional foods could have included a large variety of wild berries and other fruits, such asRubus idaeus, R. caesius, Fragaria vesca, Malus sylvestris, Cornus sanguinea, Crataegus monogyna/laevigata, Sorbus aucuparia, Viburnum opulus andRosa spp. Several other plants could have been gathered as green vegetables (Rumex crispus, Urtica dioica andCakile maritima), or could have been utilized for both their greens and seeds (Chenopodium album, Atriplex andScirpus maritimus).  相似文献   

15.
The determination of the secondary structure of the internal transcribed spacer (ITS) regions separating nuclear ribosomal RNA genes of Chlorophytes has improved the fidelity of alignment of nuclear ribosomal ITS sequences from related organisms. Application of this information to sequences from green algae and plants suggested that a subset of the ITS-2 positions is relatively conserved. Organisms that can mate are identical at all of these 116 positions, or differ by at most, one nucleotide change. Here we sequenced and compared the ITS-1 and ITS-2 of 40 green flagellates in search of the nearest relative to Chlamydomonas reinhardtii. The analysis clearly revealed one unique candidate, C. incerta. Several ancillary benefits of the analysis included the identification of mislabelled cultures, the resolution of confusion concerning C. smithii, the discovery of misidentified sequences in GenBank derived from a green algal contaminant, and an overview of evolutionary relationships among the Volvocales, which is congruent with that derived from rDNA gene sequence comparisons but improves upon its resolution. The study further delineates the taxonomic level at which ITS sequences, in comparison to ribosomal gene sequences, are most useful in systematic and other studies. Received: 14 February 1997 / Accepted: 28 March 1997  相似文献   

16.
In the present study, the entire first and second internal transcribed spacer (ITS-1 and ITS-2) regions of nuclear ribosomal DNA (rDNA) of Haemaphysalis longicornis from China were amplified by polymerase chain reaction. The 45 representative amplicons were sequenced, and sequence variation in the ITS was examined. The ITS sequences of H. longicornis were 3644 bp in size, including the part of 18S rDNA, 28S rDNA sequences and the complete ITS-1, 5.8S rDNA and ITS-2 sequences. Sequence analysis revealed that the ITS-1, 5.8S rDNA and ITS-2 of this hard tick were 1582, 152, and 1610 bp in size, respectively. The intra-specific sequence variations of ITS-1 and ITS-2 within H. longicornis were 0–2 and 0–2.2%; however, the inter-specific sequence differences among members of the genus Haemaphysalis were significantly higher, being 35.1–55.2 and 37–52% for ITS-1 and ITS-2, respectively. The molecular approach employed in this study provides the foundation for further studies of the genetic variation of H. longicornis from different hosts and geographical origins in China.  相似文献   

17.
Phylogenetic relationships in Hyaloperonospora (Oomycetes) were investigated by molecular analyses using internal transcribed spacer (ITS) sequences and collections from different host plants. Trees were inferred with Bayesian Markov chain Monte Carlo, neighbor-joining and maximum parsimony methods and rooted with Perofascia. The results are discussed with respect to host taxonomy and species concepts of downy mildews from the literature. Molecular data mainly support the use of narrow species delimitations and host range as a taxonomic marker. Hyaloperonospora brassicae turns out to be a non-monophyletic assemblage of different species. New combinations are proposed in accordance with the phylogenetic trees.  相似文献   

18.
Molecular variations of Spiranthes sinensis Ames var. australis (R.Br.) H. Hara et Kitam. ex Kitam. in Japan were examined to evaluate the validity of the seasonally differentiated groups and a dwarf form of the species, which is endemic to Yakushima Island, Japan. Sequence differences in the plastid trnL-F locus clearly distinguished Japanese S. sinensis var. australis from S. sinensis var. sinensis collected from Ryukyu. In contrast, the trnL-F sequence of S. sinensis var. australis from Sabah, Malaysia, clearly differed from that of Japanese S. sinensis var. australis, suggesting genetic heterogeneity of Spiranthes sinensis var. australis in Asia. Moreover, a molecular analysis based on the sequences of nuclear ITS1 regions indicated that there are two major groups of S. sinensis var. australis in Japan, with a geographic distribution boundary on Kyushu Island. However, the trnL-F and ITS1 sequences did not support the genetic differentiation of the seasonally differentiated groups or the dwarf form from the other Japanese individuals. Based on these molecular data, the systematic treatment of physiological and morphological variations in the Japanese population of S. sinensis. var. australis is discussed.  相似文献   

19.
The objective of this study was to detect interspecific and intraspecific genetic variations of the second internal transcribed spacer of ribosomal DNA (ITS-2), and explore the feasibility of using it as a molecular marker phylogenetic analyses and species identification among pearl oysters. ITS-2 sequences of 6 pearl oysters were amplified via polymerase chain reaction. The amplified DNA fragments were about 500 bp, spanning the partial sequences of 5.8S and 28S rRNA genes. The GC contents of all species used in this study were higher than the AT contents. The variations of sequences involved substitutions as well as insertions/deletions and were mainly concentrated in spacer regions. Sequences of about 30-bp in spacer regions showed no variations among 5 Pincatda species. Intraindividual and intraspecific polymorphisms of ITS-2 sequences were detected in some species; the interspecific variability was significantly larger than the variability within species, and the variability at the genus level was higher than that at the species level. Both neighbor-joining and parsimony analyses of ITS-2 sequences revealed the distinguishable species boundary of 6 pearl oysters, and indicated that P. chemnitzi and P. nigra were the closely related species, as were P. maxima and P. margaritifera. The findings revealed that ITS-2 sequences could be an appropriate tool for phylogenetic study of pearl oysters.  相似文献   

20.
Sequence variation among 22 isolates representing a global distribution of the prymnesiophyte genus Phaeocystis has been compared using nuclear-encoded 18S rRNA genes and two non-coding regions: the ribosomal DNA internal transcribed spacer 1 (ITS1) separating the 18S rRNA and 5.8S rRNA genes and the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase (RUBISCO) spacer flanked by short stretches of the adjacent large and small subunits (rbcL and rbcS). 18S rRNA can only resolve major species complexes. The analysis suggests that an undescribed unicellular Phaeocystis sp. (isolate PLY 559) is a sister taxon to the Mediterranean unicellular Phaeocystis jahnii; this clade branched prior to the divergence of all other Phaeocystis species, including the colonial ones. Little divergence was seen among the multiple isolates sequenced from each colonial species complex. RUBISCO spacer regions are even more highly conserved among closely related colonial Phaeocystis species and are identical in Phaeocystis antarctica, Phaeocystis pouchetii and two warm-temperate strains of Phaeocystis globosa, with a single base substitution in two cold-temperate strains of P. globosa. The RUBISCO spacer sequences from two predominantly unicellular Phaeocystis isolates from the Mediterranean Sea and PLY 559 were clearly different from other Phaeocystis strains. In contrast, ITS1 exhibited substantial inter- and intraspecific sequence divergence and showed more resolution among the taxa. Distinctly different copies of the ITS1 region were found in P. globosa, even among cloned DNA from a single strain, suggesting that it is a species complex and making this region unsuitable for phylogenetic analysis in this species. However, among nine P. antarctica strains, four ITS1 haplotypes could be separated. Using the branching order in the ITS1 tree we have attempted to trace the biogeographic history of the dispersal of strains in Antarctic coastal waters.  相似文献   

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