The phylogeny of Ptychostomum was first spacer （ITS） region of the nuclear ribosomal （nr） DNA DNA rps4 sequences. Maximum parsimony, maximum undertaken based on analysis of the internal transcribed and by combinin...The phylogeny of Ptychostomum was first spacer （ITS） region of the nuclear ribosomal （nr） DNA DNA rps4 sequences. Maximum parsimony, maximum undertaken based on analysis of the internal transcribed and by combining data from nrDNA ITS and chloroplast likelihood, and Bayesian analyses all support the conclusion that the reinstated genus Ptychostomum is not monophyletic. Ptychostomum funkii （Schwagr.） J. R. Spence （≡ Bryum funkii Schwaigr.） is placed within a clade containing the type species of Bryum, B. argenteum Hedw. The remaining members of Ptychostomum investigated in the present study constitute another well-supported clade. The results are congruent with previous molecular analyses. On the basis of phylogenetic evidence, we agree with transferring B. amblyodon Mull. Hal. （≡ B. inclinatum （Brid.） Turton≡ Bryum archangelicum Bruch ＆ Schimp.）, Bryum lonchocaulon Mull. Hal., Bryum pallescens Schleich. ex Schwaigr., and Bryum pallens Sw. to Ptychostomum.展开更多
Sequence variation of the first internal transcribed spacer of ribosomal DNA （ ITS - 1 ） was examined and its application to the study of genetic variation was explored in four populations of farter＇ s scallop Chla...Sequence variation of the first internal transcribed spacer of ribosomal DNA （ ITS - 1 ） was examined and its application to the study of genetic variation was explored in four populations of farter＇ s scallop Chlamys farreri. ITS - 1 fragments, with a length of about 300 bp,of 78 individuals collected from Dalian, Qingdao, Yantai in China and Korea respectively were amplified via PCR, cloned and sequenced. Intra-genomic variation was examined by sequencing several clones of single individuals. Alignment and polymorphism analysis detected 44 haplotypes and 50 polymorphic sites which consist of 30 substitutions and 20 indels, indicating a high level of polymorphisms. Sequence analysis also showed a very low level of intra-individual variation. All these features validated the feasibility of application of ITS - 1 fragment to population analysis. Polymorphism analysis showed that the Korea sample has the richest genetic variation, followed by Yantai and Qingdao samples. AMOVA （analysis of molecular variance） showed that the majority （96.26%） of genetic variation was distributed within populations and 3.74% resulted from among populations, but with P 〈 0.05 （ = 0.042）, indicating that the populations in this study have significant divergence. This output was basically concordant with the result arising from RAPD data and different from that from mitochondrial 16S rDNA sequence data. Discussion on this inconsistency was made accordingly.展开更多
Peritrich ciliates are highly diverse and can be important bacterial grazers in aquatic ecosystems. Morphological identifi cations of peritrich species and assemblages in the environment are time-consuming and experti...Peritrich ciliates are highly diverse and can be important bacterial grazers in aquatic ecosystems. Morphological identifi cations of peritrich species and assemblages in the environment are time-consuming and expertise-demanding. In this study, two peritrich-specifi c PCR primers were newly designed to amplify a fragment including the internal transcribed spacer(ITS) region of ribosomal rDNA from environmental samples. The primers showed high specifi city in silico, and in tests with peritrich isolates and environmental DNA. Application of these primers in clone library construction and sequencing yielded exclusively sequences of peritrichs for water and sediment samples. We also found the ITS1, ITS2, ITS, D1 region of 28 S rDNA, and ITS+D1 region co-varied with, and generally more variable than, the V9 region of 18 S rDNA in peritrichs. The newly designed specifi c primers thus provide additional tools to study the molecular diversity, community composition, and phylogeography of these ecologically important protists in dif ferent systems.展开更多
Wax gourd (Benincasa hispida Thumb. Cogn) is called white gourd, winter melon, Chinese preserving melon, Chinese squash, and don kwa. It has been cultivated in China for over 2 300 years. It probably
Fungus-growing termites cultivate species of the mutualistic basidiomycete genus Termitomyces on a substrate called the fungal comb. Identification of fungal species based on morphological features is complicated, ted...Fungus-growing termites cultivate species of the mutualistic basidiomycete genus Termitomyces on a substrate called the fungal comb. Identification of fungal species based on morphological features is complicated, tedious, and prone to errors. As an alternative, nuclear ribosomal DNA sequences consisting of the internal transcribed spacers (ITS1 and ITS2) and 5.8S rDNA were used to identify Malaysian isolates of Termitomyces sp. The morphological characteristics and molecular data indicate that Malaysian Termitomyces isolated is clearly monophyletic and belongs to the Tricholomataceae family. The Malaysian isolates analyzed in this study represent the termite fungus species called T. aurantiacus.展开更多
Ricinus communis have attracted considerable attention because of its specific industrial and pharmacological activities. DNA barcodes can be used as reliable tools to facilitate the identification of medicinal plants...Ricinus communis have attracted considerable attention because of its specific industrial and pharmacological activities. DNA barcodes can be used as reliable tools to facilitate the identification of medicinal plants for the safe use, quality control and forensic investigation. In this study, the differential identification of eight accessions of R. com-munis was investigated through DNA sequence analysis of two candidate DNA barcodes. The nucleotide sequence of internal transcribed spacers (ITS2) and chloroplast maturase gene (matK) have been determined to construct the phylogenetic tree. The phylogenetic relationships of accessions based on the nrITS2 region and partial matK region showed that all accessions in this study were related to three geographical origins. Based on sequence align-ment and phylogenetic analyses we concluded that the ITS2 sequences can distinguish R. communis accessions from different geographical distributions.展开更多
In order to analyze the sequences of the internal transcribed spacer （ITS） including the 5.8 S ribosomal DNA （rDNA） of common dermatophytes, so as to obtain a rapid and accurate method to identify the species of d...In order to analyze the sequences of the internal transcribed spacer （ITS） including the 5.8 S ribosomal DNA （rDNA） of common dermatophytes, so as to obtain a rapid and accurate method to identify the species of dermatophytes and to establish the phylogenetic tree of these species to understand their relationship, 16 strains of dermatophytes were collected and preliminarily identified by morphological characteristics. General primers for fungi ITS1 and ITS4 were used to amplify the ITS rDNA of each strains with PCR. The PCR products after purification were sequenced directly and were analyzed through internet. In the results, 11 strains were identified by means of morphological features, among which 5 strains were Trichophyton, 5 strains were Microsporum and 1 was Epidermophytoa, which was consistent with the results by molecular biology. In the 5 unidentifiable strains, 1 strain was proved to be Chrysosporium by molecular biology. These strains studied could be divided into 3 different classes as indicated in the analysis of the phylogenetic tree of the sequences in ITS, which were quite different from those of morphological classification. It is evident from the above observations that the molecular method of analysis on the ITS sequences is a rapid, highly sensitive and accurate approach for the detection of dematophyte species, however, it still exhibits some limitations needing the supplementation with morphological identification.展开更多
Phylogenetic relationships of Arundinaria and related genera (Pleioblastus, Pseudosasa, Oligostachyum, Bashania, Clavinodum, etc.) were assessed by analyzing the sequences of the nrDNA internal transcribed spacer (ITS...Phylogenetic relationships of Arundinaria and related genera (Pleioblastus, Pseudosasa, Oligostachyum, Bashania, Clavinodum, etc.) were assessed by analyzing the sequences of the nrDNA internal transcribed spacer (ITS) and the cpDNA trnL-F intergenic spacer (IGS). Comparison with trnL-F IGS sequence, the ITS region provided the higher number of parsimony informative characters, and the interspecific variation of the ITS sequence was higher than that of the trnL-F IGS sequence.The tree obtained by combining both sets of data showed that the species sampled in Arundinaria and the related genera were monophyletic and divided into two clades. The relationships and positioning of all the taxa surveryed (including A. oleosa, A. hsienchuensis, A. chino, A. amara, A. yixingensis, A. amabilis, A. fortunei, A. pygmaea, A. gramineus, A. fargesii, A. faberi, A. hupehense, Pseudosasa japonica cv. Tsutsumiana, P. japonica and Brachystachyum densiflorum) were also discussed. The results from the sequences were broadly consistent with morphological characters, appearing all these taxa sampled belong to the genus of Arundinaria. The topologies of the trees generated from individual data and the combined data were similar.展开更多
The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenc...The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenced. Together with the ITS sequences of 13 selected Rhododendron species and Bejaria racemosa downloaded from GenBank, we explored the infrageneric and sectional relationships of this important North Temperate genus by employing maximum-parsimony analysis using PAUP software. C. fastigiata and B. racemosa were designated as outgroups. The ITS-based tree inferred that: (1) Rhododendron was a well-supported monophyletic group, while subg. Therorhodion was basal to the rest of the genus; (2) Ledum was a member of Rhododendron, and its close relationship with the lepidote rhododendron was confirmed; (3) the lepidote rhododendron plus Ledum formed a strongly-supported monophyletic clade which was sister to the rest of the elepidote rhododendron; (4) the elepidote rhododendron formed a weakly-supported clade within which the monophyly of subg. Hynwrianthes and subg. Tsutsusi were strongly supported, while subg. Pentanthera and subg. Azaleastrum were polyphyletic; and (5) the monophyly of sect. Choniastnini, (subg. Azaleastrum) was strongly-supported, while subg. Tsutsusi could be sister to a weakly-supported clade composed of two sampled species of sect. Azaleastrum (subg. Azaleastrum) together with R. sentibarbatum, of subg. Mumeazalea.展开更多
基金supported by the National Natural Science Foundation of China(grantno.30670152)the National Infrastructure of Natural Resources for Science and Technology(grant no.2005DKA21403)the Natural Science Foundation of Hebei Province,China(no.C2008000158)
文摘The phylogeny of Ptychostomum was first spacer （ITS） region of the nuclear ribosomal （nr） DNA DNA rps4 sequences. Maximum parsimony, maximum undertaken based on analysis of the internal transcribed and by combining data from nrDNA ITS and chloroplast likelihood, and Bayesian analyses all support the conclusion that the reinstated genus Ptychostomum is not monophyletic. Ptychostomum funkii （Schwagr.） J. R. Spence （≡ Bryum funkii Schwaigr.） is placed within a clade containing the type species of Bryum, B. argenteum Hedw. The remaining members of Ptychostomum investigated in the present study constitute another well-supported clade. The results are congruent with previous molecular analyses. On the basis of phylogenetic evidence, we agree with transferring B. amblyodon Mull. Hal. （≡ B. inclinatum （Brid.） Turton≡ Bryum archangelicum Bruch ＆ Schimp.）, Bryum lonchocaulon Mull. Hal., Bryum pallescens Schleich. ex Schwaigr., and Bryum pallens Sw. to Ptychostomum.
基金This work was financially supported by the"863"Project of China under contract No.2002AA626020the National Nalural Science Foundation of China under contract No.30570242.
文摘Sequence variation of the first internal transcribed spacer of ribosomal DNA （ ITS - 1 ） was examined and its application to the study of genetic variation was explored in four populations of farter＇ s scallop Chlamys farreri. ITS - 1 fragments, with a length of about 300 bp,of 78 individuals collected from Dalian, Qingdao, Yantai in China and Korea respectively were amplified via PCR, cloned and sequenced. Intra-genomic variation was examined by sequencing several clones of single individuals. Alignment and polymorphism analysis detected 44 haplotypes and 50 polymorphic sites which consist of 30 substitutions and 20 indels, indicating a high level of polymorphisms. Sequence analysis also showed a very low level of intra-individual variation. All these features validated the feasibility of application of ITS - 1 fragment to population analysis. Polymorphism analysis showed that the Korea sample has the richest genetic variation, followed by Yantai and Qingdao samples. AMOVA （analysis of molecular variance） showed that the majority （96.26%） of genetic variation was distributed within populations and 3.74% resulted from among populations, but with P 〈 0.05 （ = 0.042）, indicating that the populations in this study have significant divergence. This output was basically concordant with the result arising from RAPD data and different from that from mitochondrial 16S rDNA sequence data. Discussion on this inconsistency was made accordingly.
基金Supported by the National Natural Science Foundation of China(Nos.31572255,41522604,31301867)the Strategic Priority Research Program of CAS(No.XDA11020702)the Science and Technology Development Program of Yantai(No.2014ZH073)
文摘Peritrich ciliates are highly diverse and can be important bacterial grazers in aquatic ecosystems. Morphological identifi cations of peritrich species and assemblages in the environment are time-consuming and expertise-demanding. In this study, two peritrich-specifi c PCR primers were newly designed to amplify a fragment including the internal transcribed spacer(ITS) region of ribosomal rDNA from environmental samples. The primers showed high specifi city in silico, and in tests with peritrich isolates and environmental DNA. Application of these primers in clone library construction and sequencing yielded exclusively sequences of peritrichs for water and sediment samples. We also found the ITS1, ITS2, ITS, D1 region of 28 S rDNA, and ITS+D1 region co-varied with, and generally more variable than, the V9 region of 18 S rDNA in peritrichs. The newly designed specifi c primers thus provide additional tools to study the molecular diversity, community composition, and phylogeography of these ecologically important protists in dif ferent systems.
文摘Wax gourd (Benincasa hispida Thumb. Cogn) is called white gourd, winter melon, Chinese preserving melon, Chinese squash, and don kwa. It has been cultivated in China for over 2 300 years. It probably
文摘Fungus-growing termites cultivate species of the mutualistic basidiomycete genus Termitomyces on a substrate called the fungal comb. Identification of fungal species based on morphological features is complicated, tedious, and prone to errors. As an alternative, nuclear ribosomal DNA sequences consisting of the internal transcribed spacers (ITS1 and ITS2) and 5.8S rDNA were used to identify Malaysian isolates of Termitomyces sp. The morphological characteristics and molecular data indicate that Malaysian Termitomyces isolated is clearly monophyletic and belongs to the Tricholomataceae family. The Malaysian isolates analyzed in this study represent the termite fungus species called T. aurantiacus.
文摘Ricinus communis have attracted considerable attention because of its specific industrial and pharmacological activities. DNA barcodes can be used as reliable tools to facilitate the identification of medicinal plants for the safe use, quality control and forensic investigation. In this study, the differential identification of eight accessions of R. com-munis was investigated through DNA sequence analysis of two candidate DNA barcodes. The nucleotide sequence of internal transcribed spacers (ITS2) and chloroplast maturase gene (matK) have been determined to construct the phylogenetic tree. The phylogenetic relationships of accessions based on the nrITS2 region and partial matK region showed that all accessions in this study were related to three geographical origins. Based on sequence align-ment and phylogenetic analyses we concluded that the ITS2 sequences can distinguish R. communis accessions from different geographical distributions.
文摘In order to analyze the sequences of the internal transcribed spacer （ITS） including the 5.8 S ribosomal DNA （rDNA） of common dermatophytes, so as to obtain a rapid and accurate method to identify the species of dermatophytes and to establish the phylogenetic tree of these species to understand their relationship, 16 strains of dermatophytes were collected and preliminarily identified by morphological characteristics. General primers for fungi ITS1 and ITS4 were used to amplify the ITS rDNA of each strains with PCR. The PCR products after purification were sequenced directly and were analyzed through internet. In the results, 11 strains were identified by means of morphological features, among which 5 strains were Trichophyton, 5 strains were Microsporum and 1 was Epidermophytoa, which was consistent with the results by molecular biology. In the 5 unidentifiable strains, 1 strain was proved to be Chrysosporium by molecular biology. These strains studied could be divided into 3 different classes as indicated in the analysis of the phylogenetic tree of the sequences in ITS, which were quite different from those of morphological classification. It is evident from the above observations that the molecular method of analysis on the ITS sequences is a rapid, highly sensitive and accurate approach for the detection of dematophyte species, however, it still exhibits some limitations needing the supplementation with morphological identification.
文摘Phylogenetic relationships of Arundinaria and related genera (Pleioblastus, Pseudosasa, Oligostachyum, Bashania, Clavinodum, etc.) were assessed by analyzing the sequences of the nrDNA internal transcribed spacer (ITS) and the cpDNA trnL-F intergenic spacer (IGS). Comparison with trnL-F IGS sequence, the ITS region provided the higher number of parsimony informative characters, and the interspecific variation of the ITS sequence was higher than that of the trnL-F IGS sequence.The tree obtained by combining both sets of data showed that the species sampled in Arundinaria and the related genera were monophyletic and divided into two clades. The relationships and positioning of all the taxa surveryed (including A. oleosa, A. hsienchuensis, A. chino, A. amara, A. yixingensis, A. amabilis, A. fortunei, A. pygmaea, A. gramineus, A. fargesii, A. faberi, A. hupehense, Pseudosasa japonica cv. Tsutsumiana, P. japonica and Brachystachyum densiflorum) were also discussed. The results from the sequences were broadly consistent with morphological characters, appearing all these taxa sampled belong to the genus of Arundinaria. The topologies of the trees generated from individual data and the combined data were similar.
文摘The internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (including 5.8S rRNA) of 15 Rhododendron, species, representing most sections of the genus, one Ledum species and Cassiope fastigiata were sequenced. Together with the ITS sequences of 13 selected Rhododendron species and Bejaria racemosa downloaded from GenBank, we explored the infrageneric and sectional relationships of this important North Temperate genus by employing maximum-parsimony analysis using PAUP software. C. fastigiata and B. racemosa were designated as outgroups. The ITS-based tree inferred that: (1) Rhododendron was a well-supported monophyletic group, while subg. Therorhodion was basal to the rest of the genus; (2) Ledum was a member of Rhododendron, and its close relationship with the lepidote rhododendron was confirmed; (3) the lepidote rhododendron plus Ledum formed a strongly-supported monophyletic clade which was sister to the rest of the elepidote rhododendron; (4) the elepidote rhododendron formed a weakly-supported clade within which the monophyly of subg. Hynwrianthes and subg. Tsutsusi were strongly supported, while subg. Pentanthera and subg. Azaleastrum were polyphyletic; and (5) the monophyly of sect. Choniastnini, (subg. Azaleastrum) was strongly-supported, while subg. Tsutsusi could be sister to a weakly-supported clade composed of two sampled species of sect. Azaleastrum (subg. Azaleastrum) together with R. sentibarbatum, of subg. Mumeazalea.
