真菌共祖起源的分子证据

以真菌界、动物界和植物界中的19种各类生物作为代表,从具有进化速率不同区段结构的核糖体核酸基因大亚基全序列的C3、C9及C11三个高度保守区段中鉴定出了4条真菌所共有的核苷酸序列,亦即真菌界所特有的核苷酸序列。从其保守区段C5中鉴定出了1条子囊菌门所特有的保守序列;从保守区段C7中鉴定出了1条担子菌门所特有的保守序列。研究结果为各类真菌起源于一个共同祖先提供了分子证据。用于研究的美味石耳的核糖体核酸基因大亚基全序列是由本实验室所提供;其他18种核糖体核酸基因大亚基全序列来自GenBank。     

真菌共祖起源的分子证据

以真菌界、动物界和植物界中的19种各类生物作为代表,从具有进化速率不同区段结构的核糖体核酸基因大亚基全序列的C3、C9及C11三个高度保守区段中鉴定出了4条真菌所共有的核苷酸序列,亦即真菌界所特有的核苷酸序列。从其保守区段C5中鉴定出了1条子囊菌门所特有的保守序列;从保守区段C7中鉴定出了1条担子菌门所特有的保守序列。研究结果为各类真菌起源于一个共同祖先提供了分子证据。用于研究的美味石耳的核糖体核酸基因大亚基全序列是由本实验室所提供;其他18种核糖体核酸基因大亚基全序列来自GenBank。     

中国地衣生真菌初步名录

该文是关于中国地衣生真菌汇编的首次报道,其中也包括新近采集的种类。名录中汇编了27种,其中9种为中国新记录种,包括5个中国新记录属的代表：Ampullifera,Intralichen,Marchandiomyces,Phaeosporobolus,和Stigmidium。文中还包括一个新组合种：Stigmidium cupulare (syn,Pharcidia supularis)。     

洪湖沉积物中真菌群落结构的垂直分布

湖泊沉积物中真菌的类群及其作用所知甚少。以长江中上游代表性湖泊洪湖为研究对象,从湖心截取了一个72cm长的沉积柱,通过rDNA内转录间隔区（ITS）的变性梯度凝胶电泳（DGGE）,对洪湖沉积物中真菌群落结构的垂直变化进行了分析。结果显示,DGGE条带以14－18cm层次为过渡,在2－14cm和14－72cm之间存在一定差异。Shannon-Weaver index（H′）在上下层之间有波动。聚类分析上层2－18cm和中下层18－72cm分别以不同的小类聚在一起。表明14－18cm以上和以下的类群存在差异,     

西藏真菌增补

报道在西藏亚东、林芝等地区采集到的西藏新记录真菌34种。其中包括担子菌22种,子囊菌7种和粘菌5种。凭证标本存放在吉林农业大学真菌标本室(HJAU).     

昆明动物园不同动物粪便真菌多样性(英文)

为调查不同动物粪便中真菌的多样性及不同真菌对动物粪便的偏好性,在云南昆明动物园采集了大额牛、羚牛、梅花鹿、角马、黇鹿、斑马、麋鹿、亚洲野驴、长颈鹿、野牦牛10种动物的粪便共100份。此次调查共鉴定出真菌57种,包括子囊菌31种,担子菌7种,接合菌13种,分类地位未定种类6种。其中,最常见的属为柄孢壳菌属Podospora Ces.,其次是鬼伞属Coprinus Pers及毛霉属Mucor P.Micheli ex Fr。最常见的种类为Mucor sp1,其次是Saccobolus saccoboloides Brumm和Doratomyces stemonitis(Pers.)F.J.Morton&G.Sm.。在报道的57种真菌中,有9种为中国新记录种,即Ascobolus aglaosporus Heimerl,A.behnitziensis Kirschst.,Ascodesmis sphaerospora Obrist,Coprinus hetemerus Lange&Smith,C.radiatus(Bolt.Ex Fr.)S.F.Gray,Podospora comata Milovtz.,Saccobolus dilutellus(Fuckel)Sacc.,S.saccoboloides Brumm.,Spornormiella minima(Auersw.)Ahmed&Cain.。分别研究了这10种动物粪便的真菌物种丰度及多样性,结果显示,反刍类动物粪便的真菌多样性高于非反刍类动物粪便真菌多样性。     

滇西北老君山的大型真菌分布及新记录种

报道滇西北老君山172种大型真菌,其中有63种食用菌,40种药用菌,7个中国新记录种和20个云南新记录种,并对中国新记录种进行了简要描述,分析了这些种类与特定的植被、海拔、生境的关系。     

rRNA二级结构序列用于真菌系统学研究的方法初探

本文首次利用核酸二级结构特征代替核酸碱基作为探讨类群之间亲缘关系的信号,构建了基于结构特征的子囊菌部分类群的系统进化树。该方法以S(规范的碱基对),Q(不规范的碱基对),I(单链),B(侧环),M(多分枝环)和H(发卡结构)为代码将二级结构特征区分为6种不同的亚结构类型,然后将二级结构特征转换为结构序列,并进行结构序列分析。该方法使rRNA不只局限于碱基比较,拓展了其应用范围,为揭示分子的功能与进化的关系提供了线索。结果表明,结构序列分析可用于子囊菌的系统学研究;相对于核酸序列分析,结构分析的结果似乎更加清晰地体现子囊果的演化过程。     

一株源于南极土壤的耐冷真菌Sistotrema brinkmannii(英文)

从南极Dry Valleys Feyxell Basin湖土壤中分离获得一株具有锁状联合的耐冷担子菌,核糖体DNAITS区序列分析将该菌株鉴定为Sistotrema brinkmannii。形态特征研究表明该菌株产生裸担子,其上生4-8个小梗,每个梗上产生一个肾形担孢子,丝状担子菌在南极少有报道,该菌株的生物学及生态学值得进一步研究。     

子囊菌亚门石耳科属级分类及拉诺属地位的研究

关于子囊菌亚门石耳科的属级分类问题地衣学家持有不同的观点。这些观点使属级分类出现了单属系统,二属系统,三属系统以及四属系统与五属系统。现在新二属系统,即石耳属一疱脐衣属系统已被越来越多的地衣学家和子囊菌学家所接受。但是,因为由Dodge (1968)描述的单种属拉诺属(Llanoa)的模式种与早已为人熟知的网脊石耳很相似,而近年来,这一单种属又被一些作者所接受、因此、我们不得不对该属模式种所依据的原始材料进行必要的复查。复查结果表明,拉诺属的模式种卖为网脊石耳的异名。因此,拉诺属也就成为石耳属的异名。此外,基于石耳科中三十五种地衣和五十二项特征的聚类分析结果也支持新的二属系统。     

Studies on diversity of higher fungi in Yunnan,southwestern China: A review

Yunnan is exceedingly rich in higher fungi (Ascomycota and Basidiomycota). Given that the number of fungi (including lichens) occurring in a given area is, as Hawksworth suggested, roughly six times that of local vascular plants, a total of approximately 104,000 fungal species would be expected in Yunnan. However, to date only about 6000 fungal species, including roughly 3000 species of higher fungi, have been reported from the province. Although studies on Yunnan's fungi started in the late nineteenth century, significant progress has been made only in the last forty-five years. Over the first twenty-five years of this period, studies on fungal diversity in this area have largely been about taxonomy based on morphological characters and partially on geographical distribution. Over the past twenty years, the combination of both morphological and molecular phylogenetic approaches has become the preferred method to help understand the diversity and evolution of higher fungi. This review focuses on our current knowledge of how geological, geographical, and ecological factors may have contributed to the diversity patterns of higher fungi in Yunnan. Based on this knowledge, three aspects for future studies are suggested.     

Molecular phylogeny of a circum-global, diverse gastropod superfamily (Cerithioidea: Mollusca: Caenogastropoda): pushing the deepest phylogenetic limits of mitochondrial LSU rDNA sequences

The Cerithioidea is a very diverse group of gastropods with ca. 14 extant families and more than 200 genera occupying, and often dominating, marine, estuarine, and freshwater habitats. While the composition of Cerithioidea is now better understood due to recent anatomical and ultrastructural studies, the phylogenetic relationships among families remain chaotic. Morphology-based studies have provided conflicting views of relationships among families. We generated a phylogeny of cerithioideans based on mitochondrial large subunit rRNA and flanking tRNA gene sequences (total aligned data set 1873 bp). Nucleotide evidence and the presence of a unique pair of tRNA genes (i.e., threonine + glycine) between valine-mtLSU and the mtSSU rRNA gene support conclusions based on ultrastructural data that Vermetidae and Campanilidae are not Cerithioidea, certain anatomical similarities being due to convergent evolution. The molecular phylogeny shows support for the monophyly of the marine families Cerithiidae [corrected], Turritellidae, Batillariidae, Potamididae, and Scaliolidae as currently recognized. The phylogenetic data reveal that freshwater taxa evolved on three separate occasions; however, all three recognized freshwater families (Pleuroceridae, Melanopsidae, and Thiaridae) are polyphyletic. Mitochondrial rDNA sequences provide valuable data for testing the monophyly of cerithioidean [corrected] families and relationships within families, but fail to provide strong evidence for resolving relationships among families. It appears that the deepest phylogenetic limits for resolving caenogastropod relationships is less than about 245--241 mya, based on estimates of divergence derived from the fossil record.     

Sequence variations in the large-subunit ribosomal RNA gene of ammonia (foraminifera,protozoa) and their evolutionary implications

An unusually high divergence was observed in the ribosomal RNA genes of a free-living population of foraminifera belonging to the genusAmmonia. The sequences of a large-subunit (LSU) rDNA expansion segment D1 and flanking regions were obtained from 20 specimens namedAmmonia sp. 1 andAmmonia sp. 2. The sequence divergence between the two species averages 14%. Within each species it ranges from 0.2% to 7.1% inAmmonia sp. 1 and from 0.7% to 2.3% inAmmonia sp. 2. We did not find two specimens having identical sequences. Moreover, in opposition to the generally acaepted view, rDNA sequence variations were also found within a single individual. The variations among several rDNA copies in a single specimen ofAmmonia may reach up to 4.9%. Most of the observed variations result from multiplication of CA or TA serial repeats occurring in two particularly variable regions. For single base changes, C-T transitions are most frequently observed. We discuss the evolution of expansion segments and their use for phylogenetic studies. Correspondence to: J. Pawlowski     

ITS序列同源性在苏云金芽孢杆菌分型中的应用研究

ＰＣＲ扩增了苏云金芽孢杆菌９个亚种的１６Ｓ－２３Ｓ ｒＲＮＡ基因转录间隔（ＩＴＳ）片段,它们的长度均为１４４碱基;序列同源性分析结果批出这９个亚种及其它亚种的ＩＴＳ序列高度相似,说明１６Ｓ－２３Ｓ ｒＲＮＡ基因的ＩＴＳ序列不适于苏云金孢杆菌亚种的分型。     

Molecular tools for the identification of ectomycorrhizal fungi — taxon-specific oligonucleotide probes for suilloid fungi

Five taxon-specific oligonucleotide probes are described that can be used to help identify the fungal components of ectomycorrhizae. Comparisons among partial sequence from the mitochondrial large subunit rRNA gene (mt-LrRNA) were used to select the probes, which were intended to be specific to several taxa within the suilloid group of the Boletales (Basidiomycota). Probes S1, R1, and G1 were targeted at the genera Suillus, Rhizopogon and Gomphidius ; probe G2 was designed to recognize the family, Gomphidiaceae, and probe US1 was designed to recognize all of these taxa and any other members of the suilloid group. The specificity of each probe was determined empirically by testing their ability to hybridize to PCR amplified fragments derived from 84 species of basidiomycetes. Although none of the probes exhibited their intended specificity, all specifically hybridized to useful subsets of taxa, and collectively they can be used to identify many suilloid taxa to the generic level or below. The probes were also tested for their ability to identify field collected mycorrhizae and were found to perform well.     

Improved PCR primers for the detection and identification of arbuscular mycorrhizal fungi

A set of PCR primers that should amplify all subgroups of arbuscular mycorrhizal fungi (AMF, Glomeromycota), but exclude sequences from other organisms, was designed to facilitate rapid detection and identification directly from field-grown plant roots. The small subunit rRNA gene was targeted for the new primers (AML1 and AML2) because phylogenetic relationships among the Glomeromycota are well understood for this gene. Sequence comparisons indicate that the new primers should amplify all published AMF sequences except those from Archaeospora trappei. The specificity of the new primers was tested using 23 different AMF spore morphotypes from trap cultures and Miscanthus sinensis, Glycine max and Panax ginseng roots sampled from the field. Non-AMF DNA of 14 plants, 14 Basidiomycota and 18 Ascomycota was also tested as negative controls. Sequences amplified from roots using the new primers were compared with those obtained using the established NS31 and AM1 primer combination. The new primers have much better specificity and coverage of all known AMF groups.     

Angiosperm DNA contamination by endophytic fungi: Detection and methods of avoidance

PCR primers with broad applicability are useful in many molecular-based studies; however, their universality can compromise results when DNA contaminants also are amplified. Eighty-one templates ofDahlia (Asteraceae), primarily extracted from native Mexican populations, were tested for the presence of fungal contaminants; out of these, almost 1 in 7 templates (13.6%) was contaminated. In a second survey across 12 angiosperm families using material collected in Illinois, fungal DNA contaminated over 60% of the templates analyzed. Endophytic fungi often are symptomless symbionts living within the above-ground tissues of their angiosperm hosts and are not affected by surface sterilization techniques. Recent studies have revealed their widespread occurrence and broad host range. We also present field strategies for obtaining plant material to reduce the possibility of collecting infected leaves and a simple screening test for detecting fungal DNA in angiosperm templates.