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1.
A strain of yeast isolated from insect frass collected in Thailand was found to represent a hitherto undescribed species of a basidiomycetous anamorphic genus Trichosporon. It is described as Trichosporon siamense. In the phylogenetic tree based on the D1/D2 region sequences of 26S rDNA, this yeast constitutes a cluster with several Q-9 having species of Trichosporon including T. otae and T. brassicae but is clearly differentiated from these species by 1.8% or more base substitutions. In the internal transcribed spacer region (ITS1 and ITS2), this species differs from T. scarabaeorum, the nearest species, by 6.5% base substitution.  相似文献   

2.
Ubiquinone profiles of 25 strains ofTalaromyces were determined using reversed-phase high performance liquid chromatography. Together with data of earlier authors, examination of the most recently described species allowed us to solve some taxonomic problems in the intrageneric classification. Ubiquinone Q-10(H2) was found in the majority ofTalaromyces species with aPenicillium anamorph, which are mostly placed in seriesFlavi andLutei of sectionTalaromyces. Flavi andLutei are closely related and homogeneous taxa based on their morphological characters used in the section. However, exceptionol prfiles were consistently shown byT. trachyspermus and the allied taxa of seriesTrachyspermi of the sectionTalaromyces, in which a mixture of ubiquinone Q-10(H2) and ubiquinone Q-10(H4) was found. Thus the accommodation ofT. trachyspermus and the allied taxa in the sectionTalaromyces was not supported by their ubiquinone systems.Trachyspermi is distinguished from other taxa ofTalaromyces by its production of white ascomata and rapid growth at 37°C. A new section,Trachyspermus, is proposed herein. SectionEmersonii showed heterogeneity; the ubiquinone profiles (Q-10(H2) or Q-10 and Q-10(H2)) inTalaromyces with aGeosmithia anamorph were relatively homogeneous, whereas those of another group with aPaecilomyces anamorph were considerably variable. OnlyTalaromyces with aGeosmithia anamorph can be placed in the sectionEmersonii.  相似文献   

3.
Using a genotypic approach (PCR-fingerprinting, DNA/DNA reassociation, partial sequences of the 26S rDNA gene, complete sequences of the 18S rDNA gene, and sequences of the internal transcribed spacers) five tremelloid yeast isolates from the agarics Asterophora lycoperdoides and A. parasitica were shown to be conspecific with Cryptococcus ramirezgomezianus. It was not possible to distinguish the yeast strains from A. lycoperdoides and A. parasitica using sequences from the intergenic spacer (IGS1). Phylogeny based on the 26S (D1/D2-domain), ITS1-5.8S-ITS2 and complete 18S rDNA demonstrated that C. ramirezgomezianus is closely related to several additional Cryptococcus species (C. humicola, C. longus, C. musci, C. pseudolongus) within the Trichosporonales. A new genus, Asterotremella, and a new family, Asterotremellaceae were introduced for Cryptococcus species clustering within the Trichosporonales having a ubiquinone Q-9. Cryptococcus ramirezgomezianus is a synonym of Asterotremella albida.  相似文献   

4.
Two ballistoconidium-forming yeast strains, CH 2.504 and CH 2.509, were isolated from the wilting leaves of Parthenocissus sp. collected in Yunnan, China in 1996. These two strains were assigned to the genus Bullera Derx by the characteristics of forming rotationally symmetric ballistoconidia, containing xylose in the cell hydrolysates and having Q-10 as the major ubiquinone. Molecular phylogenetic analysis based on small subunit ribosomal RNA gene (18S rDNA) and internal transcribed spacer (ITS) region sequences revealed that CH 2.504 is closely related to B. variabilis Nakase & Suzuki, while CH 2.509 is located in a clearly separate clade among the described Bullera species and related taxa. The results indicated that CH 2.509 represents a new species, for which Bullera anomala sp. nov. is the proposed name (type strain AS 2.2094T). Further DNA-DNA reassociation data showed that CH 2.504 also represents a distinct species, for which the name Bullera pseudovariabilis sp. nov. is given (type strain AS 2.2092T). This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

5.
Taxonomists find some plant genera challenging because of the few morphological differences or unclear characters among closely related species, which leads to the misidentification of taxa. DNA barcoding is an approach to identify species by using short orthologous DNA sequences, known as ‘DNA barcodes’. Concatenated rbcL and matK sequences are considered DNA barcodes for seagrasses. However, these markers are not applicable to all members of seagrasses at the species level, especially within the genus Halophila. Our previous studies indicated that the internal transcribed spacer (ITS) showed higher species resolution than the concatenated rbcL and matK sequences in the case of Halophila ovalis and closely related species. In this study, 26 ITS, two rbcL and two matK consensus sequences from 18 seagrass taxa belonging to four families collected in India, Vietnam, Germany, Croatia and Egypt were processed. Molecular ITS analysis resolved five clades. The results also indicate that the Cymodoceaceae family might be a non-monophyletic group. In conclusion, ITS could be applied as a DNA barcode for seagrasses instead of the rbcL/matK system previously proposed.  相似文献   

6.
Two strains of yeasts that contain Q-10 as the major ubiquinone, lack cellular xylose and produce large bilaterally symmetrical ballistoconidia were isolated from plants collected in a protected subtropical rain forest in Taiwan and were found to represent a new species. The taxonomic properties of this species coincide with the genus Sporobolomyces, so it is described as Sporobolomyces magnisporus sp. nov. In phylogenetic trees based on the nucleotide sequences of 18S ribosomal DNA and D1/D2 domain of 26S ribosomal DNA, this species is located in the Erythrobasidium cluster.  相似文献   

7.
Two strains of xylose-containing and Q-10-having ballistoconidiogenous yeasts isolated from plant leaves collected in Taiwan were found to represent two new species of the genus Bullera. In the phylogenetic trees based on the sequence analysis of 18S rDNA and D1/D2 domain of 26S rDNA, these species are located in the Bullera variabilis (Bulleribasidum) cluster in Hymenomycetes. They are described as Bullera begoniae sp. nov. and Bullera setariae sp. nov., respectively.  相似文献   

8.
The phylogeny of Japanese species ofChrysosplenium (Saxifragaceae) was examined using variation in DNA sequences. Sequences ofrbcL andmatK genes were compared for their feasibility for reconstructing the phylogeny ofChrysosplenium, and thematK sequences was found to give greater resolution. All but one of the 17 Japanese species have been examined formatK gene sequences and phylogenetic analysis of these data resulted in eight most parsimonious trees of 390 steps and a consistency index (Cl) of 0.823. The molecular phylogeny obtained was generally in agreement with Hara's (1957) classification based upon phenotypic similarity, although a conclusion needs extensive examination of the genus on a world-wide level. Using the phylogenetic data, character evolution was examined, especially in the characters traditionally used for grouping infrageneric taxa. Differentiation of opposite and alternate phyllotaxis appears to have occurred only once in the course of evolution ofChrysosplenium.  相似文献   

9.
The ubiquinone (coenzyme Q: Q) system of 17 strains of the form-genusChrysosporium was analyzed by high performance liquid chromatography (HPLC) and found to show a heterogeneous distribution of the major ubiquinone. Q-9, Q-10 or Q-10(H2) was found to be the major ubiquinone in 3, 9 and 5 strains, respectively. It was further demonstrated that the teleomorphs of the species characterized by Q-9 and Q-10 could be classified into two separate families, Arthrodermataceae (Q-9) and Onygenaceae (Q-10), which were defined within the revised order Onygenales by Currah. Teleomorphs ofChrysosporium species having Q-10(H2) have not been found. This paper also includes the ubiquinone system of dermatophytes which relate to the form-genusChrysosporium morphologically.  相似文献   

10.
72 Strains belonging to 44 species of ascomycetous black yeasts were analyzed for their coenzyme Q systems. Prevalent were Q-10 and dihydrogenated Q-10 systems. Members of the Dothidealean suborder Dothideineae have Q-10 (H2), while those belonging to the suborder Pseudosphaeriineae mostly have Q-10. The anamorph genus Exophiala Carmichael and the teleomorph genus Capronia Sacc. seem to be heterogenous.  相似文献   

11.
Two new species of the fungal genus Trichoderma, Trichoderma compactum and Trichoderma yunnanense, isolated from rhizosphere of tobacco in Yunnan Province, China are described based on morphological characters and phylogenetic analyses of nucleotide sequences. Our DNA sequences included the internal transcribed spacer (ITS) regions of the rDNA cluster (ITS1 and ITS2), and partial sequences of the translation elongation factor 1-alpha (tef1) and a fragment of the gene coding for endochitinase 42 (ech42). The analyses show that T. compactum belongs to the Harzianum clade, and T. yunnanense belongs to the Hamatum clade.  相似文献   

12.
Body size and colouration are two characters commonly used in the taxonomy of many animal taxa. However, they are seldom used by earthworm taxonomists because they are subject to environmental influences and tend to vary intraspecifically. In the present study, DNA sequences of the mitochondrial COI gene are used to evaluate whether specimens of the megascolecid earthworm Amynthas wulinensis Tsai, Shen & Tsai, 2001 that differ in body size and/or colouration belong to different genetic lineages. Phylogenetic analyses and morphological comparisons indicate that A. wulinensis in the previous broad sense is a species complex composed of three species differing in body size, colouration, and genital markings. Consequently, two new species, Amynthas lini and Amynthas meishanensis, are described. Taxonomic affinities of the A. wulinensis species complex are discussed, as is the feasibility of using body size and colouration in earthworm taxonomy.  相似文献   

13.
The genus Hesperodiaptomus Light, 1938, one of the most diverse groups of freshwater copepods that occur in North and Central America, plays a major role in the food webs of the alpine freshwater communities. Phylogenetic relationships of these taxa remain poorly understood due to difficulties in obtaining reliable morphological characters for phylogenetic analyses. To understand the phylogenetic relationships within this group, we reconstructed a partial phylogeny of the genus Hesperodiaptomus based on nuclear ribosomal gene sequences. Phylogenetic analyses based upon the taxa examined supported the monophyly the genus and revealed two clades. The eiseni clade comprised species that are morphologically similar to Hesperodiaptomus eiseni (Lilljeborg, 1889), and the shoshone clade included species morphologically similar to Hesperodiaptomus shoshone (S.A. Forbes, 1882). The two groups can be distinguished by a modification of the right basis, the arrangement of spinules on the distal pad of the second exopod, and the degree of presence the inner lamellar expansion of the right coxa. Handling editor: P. Spaak  相似文献   

14.
卢永彬  黄俞淞  许为斌  黄洁  刘演  向春雷  张强 《广西植物》2017,37(10):1227-1239
石山苣苔属(苦苣苔科)约30种,主要分布于我国南部的石灰岩地区.目前该属已知物种数虽少但花形态极其多样,是该科中分类最为困难的类群之一.基于分子证据,其它8个属中花形态迥异的一些物种被并入石山苣苔属.然而,该属花形态的演化趋势缺乏系统性的研究,传统分类对属的界定与分子系统学研究结果相矛盾的原因,以及是否有形态特征支持新界定的石山苣苔属还不清楚.该研究中,总共编码了19种石山苣苔属植物和9种报春苣苔属植物的35个形态特征,其中包括26个花部形态特征,在分子系统树上追踪了它们的演化路径.结果表明:无论属内还是属间,多数花部形态特征,尤其以往属的分类界定特征,在演化过程中变化频繁且发生了高度同塑性演化,这是导致传统形态分类不自然的关键因素.此外,在观察研究的所有特征中,花丝和柱头的差异可能在石山苣苔属植物共同祖先中经历了演变,或可用于区分石山苣苔属与其姐妹报春苣苔属的大多数种类.因此,在苦苣苔科植物的分类学研究中应当慎用这些花部性状作为分类依据,而且应对形态特征进行广泛地观察研究,在密集的取样和分辨率更高、更可靠的系统树上追踪它们的演化规律.更为重要的是,需要进一步研究导致复杂形态性状演化的内在分子调控机理和外在的自然选择动力,最终更加深入地理解石山苣苔属等典型喀斯特植物的演化过程和机理.  相似文献   

15.
淫羊藿是我国特有且传统的重要药用植物,逐渐步入大宗品种行列。物种的准确鉴定是药效保障和用药安全的前提,为促进其资源的合理开发和利用,该文对淫羊藿属分类学研究进行系统梳理,并对其中存在的问题及存疑类群进行阐述。淫羊藿属共发表68种,中国58种(85.3%),其中57种为特有分布,具有显著的资源优势。淫羊藿属中国类群的分类学研究较为特殊,共26种集中发表于1990s,共31种(53.4%)为国外研究者命名,且绝大多数依据少量栽培个体命名。由于缺乏广泛的形态调查和性状变异分析,导致大量类群的形态描述不准确或不全面,后续20个类群被归并或降级。依据栽培个体命名的类群是补充描述和分类修订的重点。花色、根茎类型、花茎叶的数量及着生方式等性状在中国类群中存在广泛变异。经分类修订后,该属目前包括46种、1亚种和2变种。淫羊藿属中国组类群仍处于活跃进化中,其形态变异复杂,种间关系无法得到解决,为该属分类的最大挑战。但种质资源的研究和利用需要建立在清晰的分类学基础上。未来研究应基于居群调查,完善各物种的形态描述;在此基础上,整合形态变异特征、地理分布格局和基因序列特征,检测自然种间杂交事件,从而揭示物种的分化和进化历程。  相似文献   

16.
Previous taxonomic assessments of the hydrophytic genus Nuphar Sm. (Nymphaeaceae) have inadequately considered the range of morphological variation existing in the genus. A comprehensive statistical analysis of morphological features among the recognized taxa of Nuphar is presented here, first using 10 fruit characters to delimit the separation of two infrageneric groups of taxa, and secondly using 31 characters to quantify the morphological variation found within sect. Nuphar. Results from combined phenetic analyses provided empirical support for recognition of two infrageneric groups of species in the genus (largely by fruit, stigmatic disk margin, neck, and stigmatic disk size) and for separation of taxa within sect. Nuphar (by leaf size, and fruit disk and neck size). Statistical analyses demonstrate that extensive variation in ranges of character states exists among sect. Nuphar taxa. However, a suite of qualitative and quantitative characters can be used to recognize five species and three subspecies within this predominantly Old World assemblage.  相似文献   

17.
The Cracidae are Neotropical galliform birds with 11 genera currently recognized. To investigate the questioned validity of Pipile Bonaparte, 1856 and the monotypic Aburria Reichenbach, 1853 as separate genera, we gathered data from 2727 bp of mitochondrial DNA (cytochrome b, ND2 and control region) and 151 osteological characters. Our phylogenetic analyses of DNA sequences indicated that Aburria aburri is embedded within Pipile. Also, genetic distances between Aburria and any Pipile species are equivalent to the distances estimated for other congeneric cracid species, which genus status is not doubtful. Although the osteological characters do not have phylogenetic signal to solve the phylogenetic relationships at species level, five synapomorphies were found for Aburria and Pipile. Therefore, we suggest that Pipile should be merged with Aburria, which is the oldest described genus. We estimated that speciation in this group occurred in the Plio-Pleistocene, concordant with other birds, primates and rodents that have similar geographic distribution, and proposed a diversification hypothesis based on the occurrence of sea transgressions and the formation of the Amazon Lagoon. Therefore, we conclude that these palaeogeographic events may have contributed to Neotropical taxa diversification to a greater extent than previously suspected.  相似文献   

18.
为了解柿属(Diospyros)植物的叶表皮特征,在光学显微镜下观察了46种2变种植物的叶表皮微形态特征,并进行了主成分分析。结果表明,柿属植物的叶表皮微形态可分为2组:A组的表皮细胞为不规则形,垂周壁浅波状或深波状;B组的表皮细胞为多边形,垂周壁平直或弓形。气孔全部位于下表皮,以无规则型为主,但同时有辐射型、环列型和十字型气孔存在。大多数种具有表皮毛,表皮毛有非腺毛和头状腺毛的区别。柿属植物的叶表皮微形态特征类型多样,能够为部分类群的分类提供较好的形态学证据。  相似文献   

19.
20.
Based on the results of morphological and DNA sequence (partial D1–D3/D7–D8 nuLSU and partial nuSSU-ITS1-5.8S rDNA) data, three species of Plasmopara are revised and reclassified. A species of Plasmopara parasitic on Scorzonera, invalidly published several times, is assigned to a new genus and species under Novotelnova scorzonerae. Plasmopara euphrasiae sp. nov. is segregated from P. densa, and P. centaureae-mollis is revised and relegated to synonymy of Bremia centaureae. All taxa are described and illustrated.  相似文献   

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