菌寄生属研究进展

菌寄生属通常寄生于其他真菌子实体上,是子囊菌的重要类群之一,在生物医药和工农业等方面具有经济重要性。简述了菌寄生属在资源与分类、系统发育和寄主专化性等方面的研究现状及进展。已有的分子系统学研究表明,菌寄生属是多谱系类群,形成多个分支,各分支与其无性型特征和寄主种类有关。今后需进一步澄清属种概念,建立稳定的有性阶段-无性阶段对应关系,在全面了解其物种多样性和地理分布特点基础上,深入探讨种间系统发育关系。     

座囊菌目及相关类群属间关系的系统学初探

本研究对座囊菌纲部分类群的18S和28SnrDNA部分序列片段进行分析,探讨它们属间的系统学关系。邻接法和简约法分析结果显示,座囊菌纲供试类群为单起源,形成三个独立的分支并获得较强的支持率,分别代表座囊菌目、葡萄座腔菌目和格孢腔菌目。结果还显示,座囊菌纲中分类地位不确定的属Macrovalsaria与Botryosphaeria的关系相对接近,应该归于葡萄座腔菌目;历史上分类地位有疑问的Neopeckia和Dothidotthia两个属处于不同的目中,前者属于座囊菌目,后者为葡萄座腔菌目的成员;座囊菌目的Plowrightia属并非单系群,该属成员分别与Dothidea、Neopeckia和Sydowia三个属聚类在一起;现行的Botryosphaeria属也非单系群,其属的概念有待澄清。格孢腔菌目参试的7个属形成一个单系群,但属间的支持率非常低,表明它们应该在较高的分类等级上予以区分;序列分析的结果支持了基于形态学特征将Phragmogibbera纳入格孢腔菌目的分类观点。     

葡萄座腔菌科真菌的系统学和多样性探讨

葡萄座腔菌科的真菌是子囊菌中重要的代表性类群,是农林生态系统中重要的组成部分。该类真菌物种资源丰富、全型特征多样,包括许多具有重要经济价值和生态功能的类群,隶属子囊菌门(Ascomycota)果囊菌亚门(Pezizomycotina)座囊菌纲(Dothideomycetes)葡萄座腔菌目(Botryosphaeriales)。本文在概述葡萄座腔科真菌生态功能的基础上,回顾了一百年来该类真菌目、科、属和种各级分类单元的建立及其系统分类研究历史,重点评述以von ArxMüller和Barr提出的两大分类系统,总结了基于全型形态特征和多基因序列分析的现代分子系统学研究现状。虽然该类群的分类系统日趋完善,但中国的相关研究存在资源挖掘不够深入、研究的系统性不足等问题。主要针对资源挖掘必要性、分类依据科学性、物种特征全息化等几个方面存在的问题进行了分析和讨论,并对未来研究方向进行展望,以期为该类真菌的深入研究与开发利用提供科学依据。     

葡萄座腔菌科研究进展——鉴定,系统发育学和分子生态学

葡萄座腔菌科（Botryosphaeriaceae）真菌是农业和林业上重要的病原菌、内生真菌或潜在的致病菌,主要引起树木溃疡病。这类真菌种类繁多,寄主范围广,广泛分布于全球,在生态系统中占有重要的地位。本文综述了近年来国内外在葡萄座腔菌科的分子生态学研究方面取得的新进展。简要介绍了葡萄座腔菌科真菌物种鉴定及其研究方法方面的发展,并列出了2006年以来发现的6个新属和38个新种;概述了该科各个种、属之间的系统发育关系以及科内区分的18个群。在真菌种群遗传结构及其与寄主关系方面,已有研究表明葡萄座腔菌科真菌大体可分为寄主专化型和广谱寄生型两种类型,并已经揭示了无性型为Diplodia,Lasiodiplodia和Dothiorella等部分种群的遗传结构及它们与寄主之间的联系。在种内遗传多样性和基因流动研究方面,展示了利用ISSR、SSR等分子标记方法取得的一些重要结果,有些种群（如Lasiodiplodia theobromae）没有寄主专化性,它们在不同寄主间表现出很强的基因流动,但在不同区域内的基因交流却很有限。文章最后讨论了该科分子生态学研究有待进一步解决的问题。     

DNA分子标记技术在真菌系统学研究中的应用及影响

DNA分子标记技术为真菌系统进化研究提供了许多新的方法,真菌分子系统学已成为一门成熟的学科。简述了真菌分子系统学的发展简史和代表性的研究方法以及对真菌系统学的主要贡献,包括将广义的真菌划分为3个类群,粘菌和卵菌不再属于真菌界成员。真菌生命之树项目的研究结果对真菌界高阶分类系统作出重大调整,将先前的4个门(壶菌门、接合菌门、子囊菌门和担子菌门)变为7个门(微孢子虫门、壶菌门、新丽鞭毛菌门、芽枝霉门、球囊菌门、子囊菌门和担子菌门)和4个亚门,并对真菌各类群概念作出修订。此外,DNA分子标记技术对真菌种概念的认识、有性型-无性型关联及分子生态学等研究领域产生了重要影响。     

中国大单孢属真菌一新纪录种

大单孢属(Aplosporella)隶属于真菌界(Fungi),子囊菌门(Ascomycota),盘菌亚门(Pezizomycotina),座囊菌纲(Dothideomycetes),葡萄座腔菌目(Botryosphaeriales),葡萄座腔菌科(Botryosphaeriace-ae)的一个无性态属。大单孢属成员常常生于植物的小枝条上,引起植物小枝条枯死。该属包含多个异源种,这些异源种需要进一步归到其他相关属里去[1]。     

枣树干腐病病原菌的鉴定

对山西省枣树上发生的一种新病害进行了调查和病菌分离与培养研究。通过形态学特征观察和rDNA ITS序列分析,证明该病菌为葡萄座腔菌Botryosphaeria dothidea的无性阶段Fusicoccum aesculi。     

高产紫杉醇内生真菌J11的鉴定

从南方红豆杉(Taxus chinensis var.mairei)的幼茎中分离出一株产紫杉醇内生真菌J11.菌株J11的发酵提取物经高分辨质谱分析,证实J11菌株可产紫杉醇.提取该菌株的基因组DNA,扩增核糖体internal transcribed spacer(ITS)和28S核糖体large subunit rRNA gene(LSU)序列,经测序获得该菌的ITS序列和LSU序列.序列比对和检索结果表明,J11菌株为葡萄座腔菌(Botryosphaeria ssp.)属中的一个新菌株.形态学鉴定符合葡萄座腔菌属特征,高效液相色谱分析表明,J11菌株的紫杉醇含量约为615.1μg/L.本研究首次证实葡萄座腔菌J11是一株高产紫杉醇野生型菌株,具有潜在的应用前景.     

虫草属分子系统学研究现状

近年来的分子系统学研究结果表明 ,麦角菌目 (Clavicipitales)与肉座菌目 (Hypocreales)以及虫草属[Cordyceps(Fr.)Link]与麦角菌科 (Clavicipitaceae)内的有关种属关系密切 ,但虫草属为一多系群 ,其中只有新虫草亚属的种类形成单系群。虫草属种类的进化与寄主有一定的关系 ,有关研究显示它们在亲缘关系相差很大的寄主之间多次转移。多个独立的ITS序列研究表明 ,阔孢虫草 (CordycepscrassisporaM .Zangetal.)、甘肃虫草(CordycepsgansuensisK .Y .Zhangetal.)、多轴虫草 (CordycepsmultiaxialisM .Zang&Kinjo)、尼泊尔虫草 (CordycepsnepalensisM .Zang&Kinjo)与冬虫夏草 [Cordycepssinensis(Berk.)Sacc.]为同一物种 ;RAPD和ITS序列分析还显示不同地理分布的冬虫夏草存在明显的遗传分化。分子生物学方法在确定有性型与无性型的关系上已经为多种虫草菌提供了有力的证据。本文主要对虫草属分子系统学研究现状进行了综述 ,同时就分子生物学研究中的取样问题、一些分子方法的适用范围以及有性型与无性型的关系等问题进行了讨论。     

生于刺柏枝干瘿瘤上的暗葡萄腔菌属1新种

自宁夏回族自治区固原市泾源县采集到刺柏Juniperus formosana枝干瘿瘤的病害标本,采用常规组织分离法与单胞分离法获得7株暗葡萄腔菌属Phaeobotryon真菌,基于分子系统学结合形态学的方法明确了菌株的分类地位。结果表明：这7个菌株为新种——刺柏暗葡萄腔菌P. juniperi。该种与漆树暗葡萄腔菌P. rhoinum亲缘关系近,但形态学比较描述显示该种的分生孢子[（24.5～27.5）×（12.0～13.5）μm]明显大于P. rhoinum [(19.0～21.0)×（7.5～9.0）μm）]。这也是暗葡萄腔菌属真菌在刺柏上的首次记录。     

Two new species of Botryosphaeria with brown, 1-septate ascospores and Dothiorella anamorphs

Botryosphaeria sarmentorum sp. nov. and B. iberica sp. nov. are described and illustrated. These two species are unusual in this genus because of their brown, 1-septate ascospores. Phylogenetic analysis based on ITS and EF1-alpha sequences place them within the clade containing species with Fusicoccum anamorphs. The brown, 1-septate conidia, however, do not conform to Fusicoccum. Therefore phylogenetically and morphologically the anamorphs of these two species belong in a genus distinct from any of the currently accepted anamorph genera assigned to Botryosphaeria. Through a study of the type species of Dothiorella this genus is resurrected to accommodate anamorphs of Botryosphaeria with brown, 1-septate conidia. Botryosphaeria sarmentorum is shown to be the teleomorph of Diplodia sarmentorum, which in turn is transferred to Dothiorella. Otthia quercus is transferred to Botryosphaeria as B. quercicola nom. nov.     

Botryosphaeria viticola sp. nov. on grapevines: a new species with a Dothiorella anamorph

Botryosphaeria viticola sp. nov., isolated from pruned canes of Vitis vinifera in NE Spain, is described and illustrated. Phylogenetic analysis based on ITS and EF1-alpha sequences and morphological characters of both anamorph and teleomorph confirmed this taxon to be included within the group of Botryosphaeria species with Dothiorella anamorphs. It is related most closely to B. sarmentorum and B. iberica from which it differs in morphological characters of the teleomorph and DNA sequences.     

Phylogenetic and morphological re-evaluation of the Botryosphaeria species causing diseases of Mangifera indica

Species of Botryosphaeria are among the most serious pathogens that affect mango trees and fruit. Several species occur on mangoes, and these are identified mainly on the morphology of the anamorphs. Common taxa include Dothiorella dominicana, D. mangiferae (= Natrassia mangiferae), D. aromatica and an unidentified species, Dothiorella 'long'. The genus name Dothiorella, however, is acknowledged as a synonym of Diplodia. This study aimed to characterize and name the Botryosphaeria spp. associated with disease symptoms on mangoes. To achieve this isolates representing all four Dothiorella spp. mentioned above were compared with the anamorphs of known Botryosphaeria spp., based on conidial morphology and DNA sequence data. Two genomic regions were analyzed, namely the ITS rDNA and beta-tubulin regions. The morphological and molecular results confirmed that the fungi previously identified from mango as species of Dothiorella belong to Fusicoccum. Dothiorella dominicana isolates were identical to isolates of F. parvum (teleomorph = B. parva). A new epithet, namely F. mangiferum, is proposed for isolates previously treated as D. mangiferae or N. mangiferae. Isolates of D. aromatica were identified as F. aesculi (teleomorph = B. dothidea). A fourth Fusicoccum sp. also was identified as those isolates previously known as Dothiorella 'long'. A key is provided to distinguish these species based on anamorph morphology in culture. This study provides a basis for the identification of Botryosphaeria species from mango, which is important for disease control and to uphold quarantine regulations.     

Combined multiple gene genealogies and phenotypic characters differentiate several species previously identified as Botryosphaeria dothidea

Botryosphaeria dothidea is one of the most commonly reported species in a genus of important pathogens of woody plants. This taxon generally is accepted to represent a species complex, and hence its identity remains unclear. Previous studies either have treated B. dothidea as the valid name for B. ribis and B. berengeriana or argued for them to be separate entities. To add to the confusion, no ex-type cultures are available for either B. dothidea or B. ribis. The aim of the present study, therefore, was to recollect and characterize these fungi and designate a set of reference cultures that can be used in future studies. To this end, morphological, cultural and multi-allelic DNA sequence datasets from the rDNA (ITS 1, 5.8S, and ITS 2), β-tubulin and EF1-α genes were used to fully characterize these species. Botryosphaeria dothidea was found to be distinct from B. ribis, while B. berengeriana was retained as synonym of the former name. Furthermore, Fusicoccum aesculi is accepted as anamorph of B. dothidea, while the anamorph of B. ribis is newly described as F. ribis sp. nov. Botryosphaeria ribis could be distinguished from B. parva based on β-tubulin and EF1-α sequence data. A combined phylogeny of the three gene regions used in this study also showed that the genus Botryosphaeria represents two distinct phylogenetic assemblages that correspond to species with Diplodia and Fusicoccum anamorphs.     

DNA phylogeny, morphology and pathogenicity of Botryosphaeria species on grapevines

Several species of Botr yosphaeria are known to occur on grapevines, causing a wide range of disorders including bud mortality, dieback, brown wood streaking and bunch rot. In this study the 11 Botryosphaeria spp. associated with grapevines growing in various parts of the world, but primarily in South Africa, are distinguished based on morphology, DNA sequences (ITS-1, 5.8S, ITS-2 and EF1-α) and pathological data. Botryosphaeria australis, B. lutea, B. obtusa, B. parva, B. rhodina and a Diplodia sp. are confirmed from grapevines in South Africa, while Diplodia porosum, Fusicoccum viticlavatum and F. vitifusiforme are described as new. Although isolates of B. dothidea and B. stevensii are confirmed from grapevines in Portugal, neither of these species occurred in South Africa, nor were any isolates of B. ribis confirmed from grapevines. All grapevine isolates from Portugal, formerly presumed to be B. ribis, are identified as B. parva based on their EF1-α equence data. From artificial inoculations on grapevine shoots, we conclude that B. australis, B. parva, B. ribis and B. stevensii are more virulent than the other species studied. The Diplodia sp. collected from grapevine canes is morphologically similar but phylogenetically distinct from D. sarmentorum. Diplodia sarmentorum is confirmed as anamorph of Otthia spiraeae, the type species of the genus Otthia (Botryosphaeriaceae). A culture identified as O. spiraeae clustered within Botryosphaeria and thus is regarded as probable synonym. These findings confirm earlier suggestions that the generic concept of Botryosphaeria should be expanded to include genera with septate ascospores and Diplodia anamorphs.     

Development of simple sequence repeat markers for Botryosphaeria spp. with Fusicoccum anamorphs

We report the development of eight sets of microsatellite markers for the ascomycete fungus and tree pathogen, Botryosphaeria parva. The primers were identified after cloning and sequencing of fragments amplified using simple sequence repeat (SSR) primers. Genome walking was used to determine unknown sequences on either side of new SSRs. The primers were tested and proved useful in nine other Botryosphaeria species that all have Fusicoccum anamorphs, similar to B. parva.     

Phylogeny of the Botryosphaeriaceae reveals patterns of host association

Three anamorph genera of the Botryosphaeriaceae namely Diplodia, Lasiodiplodia and Dothiorella have typically dark, ovoid conidia with thick walls, and are consequently difficult to distinguish from each other. These genera are well-known pathogens of especially pine species. We generated a multiple gene genealogy to resolve the phylogenetic relationships of Botryosphaeriaceae with dark conidial anamorphs, and mapped host associations based on this phylogeny. The multiple gene genealogy separated Diplodia, Lasiodiplodia and Dothiorella and it revealed trends in the patterns of host association. The data set was expanded to include more lineages of the Botryosphaeriaceae, and included all isolates from different host species for which ITS sequence data are available. Results indicate that Diplodia species occur mainly on gymnosperms, with a few species on both gymnosperms and angiosperms. Lasiodiplodia species occur equally on both gymnosperms and angiosperms, Dothiorella species are restricted to angiosperms and Neofusicoccum species occur mainly on angiosperms with rare reports on Southern Hemisphere gymnosperms. Botryosphaeria species with Fusicoccum anamorphs occur mostly on angiosperms with rare reports on gymnosperms. Ancestral state reconstruction suggests that a putative ancestor of the Botryosphaeriaceae most likely evolved on the angiosperms. Another interesting observation was that both host generalist and specialist species were observed in all the lineages of the Botryosphaeriaceae, with little evidence of host associated co-evolution.     

引起蓝莓茎溃疡病的葡萄座腔菌属Botryosphaeria二新种

在我国华南地区发现了两个引起蓝莓茎溃疡病的Bofryosphaeria新种,即B.dolichospermatii和B.fujianensis,本研究对这两个物种进行了详细的形态学描述,并制作了图版.基于/TS、LSU、tef1-α 和TUB等4个基因片段的综合系统学分析,B.dolichospermatii和B.fu...     

葡萄座腔菌属ITS-nrDNA的分子系统学分析

对收集的22株和GenBank下载的40株葡萄座腔菌Botryosphaeria ITS序列构建了MP(Maximum parsimony)进化树。在以Leucostoma为外群的情况下,来自我国(主要是陕西)的葡萄座腔菌树木溃疡病菌总体上可分为2个大群,BDGroup1与GenBank上报道的B.dothidea被聚在一起,BD Group2菌株全部来自我国关中咸阳,独立成群,与Botryosphaeria属其他种亲缘关系远。培养特征、分生孢子大小和致病性测定显示:来自我国的苹果轮纹病菌、苹果干腐病菌、梨轮纹病菌、桃树流胶病菌同B.dothidea亲缘关系近,在MP树中聚在一起(BD Group1)。ITS序列分析结果支持B.dothidea与B.berengeriana为同物异名的观点。B.ribis与B.parva亲缘关系近,而与B.dothidea亲缘关系远,支持B.ribis与B.dothidea为不同种的观点。