COI基因作为丛赤壳科真菌DNA条形码的测试

以丛赤壳科33种76个菌株为材料,探讨COI基因作为该科DNA条形码的可能性。结果表明,该DNA片段存在较多内含子,为了获取某些种的短片段,需设计许多引物,PCR扩增与测序成功率低,难以达到便捷、快速的物种鉴定的目的。因此,COI不宜作为丛赤壳科的DNA条形码。对已获得的少数片段进行分析表明,该基因对丛赤壳科部分种具有较强的物种鉴别力。     

ITS作为粒毛盘菌属DNA条形码的探索

以种内与种间差异以及PCR扩增和测序成功率为评价DNA条形码的重要指标,探索ITS序列作为粒毛盘菌属DNA条形码的可行性。结果表明,ITS成功区分了研究涉及的22个种,其PCR扩增和测序成功率为100%,该片段有望成为该属区分物种的DNA条形码。     

新丛赤壳属真菌DNA条形码研究

以新丛赤壳属19个种为材料,选择ITSrDNA,β-tubulin,EF—1α和RPB2作为候选基因,对获得的205个序列片段采用不同方法进行分析,筛选该属的DNA条形码．将种内与种间序列差异以及序列获得的难易程度作为评价指标．结果表明,任何一个单独的基因都不宜作为其DNA条形码,EF-1α与RPB2基因组合可以准确识别种内与种间差异,建议作为该类真菌的DNA条形码．研究过程中,将形态学与序列分析相结合,发现顶环新丛赤壳和小孢新从赤壳两个隐存种．     

从真菌全基因组中筛选丛赤壳科的DNA条形码

将粗糙脉孢菌(Neurospora crassa)的注释基因分别与30 种丝状子囊菌基因组比较, 根据E值大小预测同源序列, 从中选择Hsp90, AAC, CDC48和EF3作为候选基因, 以丛赤壳科(Nectriaceae)13 个属34 个概念清晰的种为材料, 对215个序列片段采用不同方法进行分析, 筛选适合于该科的DNA 条形码. 将种内与种间序列差异以及序列获得的难易程度作为评价指标. 结果表明,Hsp90 和AAC基因虽然具有较高的 PCR 扩增与测序成功率, 但种内、种间距离频率分布存在重叠, 可能导致部分种的鉴定错误;CDC48基因可以恰当地区分种内与种间差异, 但扩增与测序成功率相对较低; EF3基因不存在种内、种间遗传距离重叠, 序列容易获得, 适合作为该科真菌的DNA 条形码.     

木霉属5个中国新记录种及2种木霉在中国的新分布

对来自北京、广东、黑龙江、河南、湖北、湖南、吉林、内蒙古、浙江的木霉属资源进行系统分类研究,报道了该属5个中国新记录种：桤木木霉Trichoderma alni,絮状木霉T. floccosum,近洋大戟草木霉T. parapiluliferum,普丽西拉木霉T. priscilae和森吉木霉T. songyi,并提供了其宏观和微观特征的详细描述及图示。基于联合rpb2和tef1基因序列的系统发育分析,为确定上述种的分类地位提供了佐证。此外,表明近渐绿木霉T. paraviridescens和西蒙斯木霉T. simmonsii在我国广泛分布。     

具有无色子囊孢子的木霉属两新种

报道了采自我国安徽省金寨县天堂寨的木霉属 Trichoderma 两个新种。新种天堂寨木霉T. tiantangzhaiense位于Hypocreanum分支,子座黄褐色至淡褐色,平垫状至盘状,子囊孢子相对较小;新种余氏木霉T. yui与沃格玛木霉T. voglmayrii亲缘关系较近,具有橙褐色至金棕色子座,褐色至红褐色孔口区和绿色分生孢子。本文提供了这两种木霉宏观和微观特征的详细描述及图示,并探讨了其分类地位。     

山葡萄种质资源DNA条形码通用序列的筛选

对山葡萄(Vitis amurensis)种质资源样品的ITS、ITS2、psb A-trn H、rbc L和mat K序列进行PCR扩增及测序,优化PCR反应的退火温度,比较各序列的扩增效率、测序成功率、品种间和品种内的差异及barcoding gap图,使用BLAST和NJ树法比较不同序列的鉴定能力,最终从5条DNA片段中筛选出可用于山葡萄种质资源鉴定的DNA条形码通用序列。结果表明,在采集的11份33个山葡萄样品中,psb A-trn H和ITS2序列的扩增与测序成功率较高,其品种间、品种内差异及barcoding gap较ITS、rbc L和mat K序列具有明显的优势,且ITS2序列能够鉴别psb A-trn H序列无法鉴别的品种。实验证明,ITS2和psb A-trn H序列是较适合鉴别山葡萄资源的DNA条形码序列组合。DNA条形码弥补了形态学鉴定的不足,可为山葡萄种质资源的准确鉴定提供科学依据。     

湖北木林子保护区山矾属植物空间分布格局及其关联性

物种共存机制是生态学研究的重要问题。以同属物种山矾、光叶山矾为研究对象,分析其空间分布格局和种内、种间关联性特征。将山矾、光叶山矾分为4个径级,分别归属幼树、小树、中树和成年树4个生长阶段。采用单变量成对相关函数分析空间分布格局特征;双变量成对相关函数分析种内、种间关联性。结果显示:山矾和光叶山矾径级结构基本一致,均属增长型种群。在完全空间随机模型下,山矾和光叶山矾主要呈聚集分布,逐渐过渡为均匀分布;在异质泊松模型下,只在小尺度上聚集,较大尺度范围呈随机分布。种内关联上,山矾各生长阶段主要呈正关联,逐渐向无关联过渡,光叶山矾除小树与成年树外,其余均呈正关联;排除生境异质性影响后,小尺度呈正关联,其余尺度无关联。种间关联上,在幼树、小树物种对中主要呈负关联,中树、成年树物种对中多为无关联。研究表明,同属物种山矾和光叶山矾呈种内聚集、种间分离的空间构型,在竞争排除作用下实现同属共存,有利于亚热带常绿落叶阔叶混交林群落结构稳定和物种多样性维持。     

锦葵科植物DNA条形码通用序列的筛选

对锦葵科植物样品的ITS、ITS2、rbcL、matK和psbA-trnH序列进行PCR扩增和测序,比较各序列的扩增效率、测序成功率、种内和种间变异的差异以及barcoding gap图,使用BLAST1和Nearest Distance方法评价不同序列的鉴定能力,进而从这些候选序列中筛选出较适合锦葵科植物鉴别的DNA条形码序列。结果表明,ITS序列在采集的锦葵科植物11个种26个样品中的扩增成功率较高,其种内、种间变异差异和barcoding gap较ITS2、psbA-trnH及rbcL序列具有更明显的优势,且纳入60个属316个种共1228个样品的网上数据后,其鉴定成功率可达89.9%。psbA-trnH序列的扩增和测序成功率最高,其鉴定成功率为63.2%,并能鉴别一些ITS序列无法鉴别的种。实验结果表明,ITS和psbA-trnH是较适合鉴别锦葵科植物的DNA条形码序列组合。     

基于叶绿体DNA atpB-rbcL区序列探讨石蒜属种间系统发育关系

摘要：为了探讨石蒜属（Lycoris Herb.）的种间系统发育关系,对石蒜属95个材料包括15种、4变种及2个人工杂种的叶绿体 DNA atpB-rbcL间隔区进行了测序,结合花部形态和核型特征,探讨了石蒜属种间系统关系及其可能的杂交起源,结果表明：在系统发育树上亲缘关系近的材料聚在一起,其中矮小石蒜（L. radiata var. pumila）和换锦花（L. sprengeri）与2个人工杂交种（Hybrid 1、Hybrid 2）、麦秆石蒜（L. straminea）、江苏石蒜（L. houdyshelii）、短蕊石蒜（L. caldwellii）和乳白石蒜（L. albiflora）具有密切的亲缘关系。atpB-rbcL序列揭示的石蒜属种间关系与染色体核型的分类结果部分一致,主要表现在具有近端部着丝粒(A)染色体的种与具有中部(M)和端部(T)着丝粒染色体的种各成一支,与形态和染色体分类结果一致;不同之处在于具有中部、端部和近端部着丝粒染色体的种分散在两个主要分支内,进一步验证了具有中部、端部和近端部3种着丝粒类型染色体组的石蒜如麦秆石蒜、江苏石蒜、短蕊石蒜和乳白石蒜等是杂交起源的假设,结合2个人工杂交种分析,揭示了短蕊石蒜和乳白石蒜的近端部着丝粒染色体来源于换锦花;麦秆石蒜和江苏石蒜近端部着丝粒染色体来源于矮小石蒜。     

木霉属研究概况

木霉属Trichoderma真菌种类众多、分布广泛,是一类重要的可再生自然资源,具有较高经济价值和应用前景。简要概述其经济重要性、分类学研究和系统发育等方面的研究现状及进展,遵循现行命名法规采用该类群的正确名称,并对后续研究提出了建议。     

Photosynthesis,Transpiration, and Water Use Efficiency of Two Puccinellia Species on the Songnen Grassland,Northeastern China

The intra- and inter-specific variations in net photosynthetic (P _N) and transpiration (E) rates and water use efficiency (WUE) of Puccinellia tenuiflora and Puccinellia chinampoensis leaves were compared. The two species experienced a similar habitat, but differed in leaf area, leaf colour, and nitrogen contents. Leaf P _N and E for both reproductive and vegetative shoots of the two species declined with leaf age. P _N for reproductive shoots was less than for vegetative shoots, but their E was greater than that of vegetative shoots in the dry season. The average P _N and E for reproductive shoots of P. tenuiflora were lower than those of P. chinampoensis, but higher for vegetative shoots.     

Phylogenetic placement of the anamorphic tribe Ustilaginoideae (Hypocreales, Ascomycota)

Tribe Ustilaginoideae (Hypocreales, Ascomycetes) is made up of three anamorph genera, Munkia, Neomunkia and Ustilaginoidea. Species of Munkia and Neomunkia develop on the culms of bamboo (Chusquea spp.) and have a neotropical distribution while species of Ustilaginoidea infect the florets of various grasses and are pantropical in distribution. In this study we evaluated the phylogeny of the tribe and assessed hypotheses regarding its affinity to clavicipitalean teleomorphic groups. To support phylogenetic analyses, morphology of representatives of several key species of Ustilaginoideae was examined also. Phylogenetic analyses using sequences of the large subunit of the ribosomal RNA gene suggest that members of Ustilaginoideae are distinct from teleomorphic genera of Clavicipitaceae and that Ustilaginoideae should be recognized as a monophyletic group within Hypocreales. However, phylogenetic analyses did not resolve the placement of Ustilaginoideae in Clavicipitaceae or Hypocreaceae, suggesting that it might be a distinct lineage within Hypocreales. This evaluation supported the monophyly of tribes Balansieae and Clavicipeae in the family Clavicipitaceae.     

南亚热带阔叶林展叶物候及其种内种间差异探讨

植物的展叶物候与植物的生长和生存密切相关,但未见有定性的研究植物展叶物候的种间和种内差异与验证亚热带常绿阔叶林植物展叶物候系统发育关系的报道。为了更好地理解南亚热带常绿阔叶林物种共存机制和预测不同物种对气候变化的响应,该研究于2013年1月至2014年12月期间,在中国科学院华南植物园鼎湖山自然保护区内对44个树种的展叶物候进行了连续观测,利用变异系数定性分析了气候因子、系统发育关系对展叶始期及其种内和种间差异和展叶期的影响。结果表明:鼎湖山自然保护区植物展叶始期主要集中在3-5月,植物展叶物候受气候因子影响不显著;不同物种的展叶物候种内变异差别较大,其中种内差异最大的是红皮紫棱(Craibiodendron kwangtungense)(变异系数为0.74),最小的是广东润楠(Machilus kwangtungensis)(变异系数为0.09);基于APGⅢ物种数据库构建谱系树,发现植物间的系统发育关系对展叶物候无显著影响,即亲缘关系近的物种,展叶期并不相似。该研究结果对于理解生态系统过程,如碳循环、物质能量流动,以及展叶物候对气候变化的适应性具有重要意义。     

Evidence for a new lineage of primary ambrosia fungi in Geosmithia Pitt (Ascomycota: Hypocreales)

Geosmithia is a genus of mitosporic filamentous fungi typically associated with phloeophagous bark beetles world-wide. During this study, the fungal associates of ambrosia beetles Cnesinus lecontei, Eupagiocerus dentipes, and Microcorthylus sp. from Costa Rica, were studied using morphology and DNA sequences. Fungal associates belonged to four undescribed Geosmithia species. Geosmithia eupagioceri sp. nov. and G. microcorthyli sp. nov. are evidently primary ambrosia fungi of their respective vectors E. dentipes and Microcorthylus species. They both have convergently evolved distinct morphological adaptations including the production of large, solitary and globose conidia, and yeast-like cells. Tunnels of C. lecontei contained an undescribed Geosmithia species, but its nutritional importance for its vector is unclear. An auxiliary ambrosia fungus, Geosmithia rufescens sp. nov., was found associated with both G. eupagioceri and the Geosmithia species associated with C. lecontei. G. microcorthyli is genetically quite similar to the phloem-associated Geosmithia sp. 8 from Europe. Large differences in morphology between these two species suggest the rapid co-evolution resulting from the close symbiosis of the former with its beetle host. The ITS rDNA sequences of G. microcorthyli and Geosmithia sp. 8 were not diagnostic, suggesting that alternative markers such as EF-1α, IGS rDNA or β-tubulin should be used, together with morphological and ecological data, for species delimitation in this genus. The primary ambrosia fungi described here are derived from phloem-associated ancestors, and represent two independent lineages of ambrosia fungi in the Hypocreales and a new ecological strategy within Geosmithia.     

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。     

Phylogenetic relationships of the sea eagles (genus Haliaeetus): reconstructions based on morphology, allozymes and mitochondrial DNA sequences

The relationships of eight extant species of sea eagles (genus Haliaeetus ) and some potentially related Accipitrid genera were investigated. A phylogenetic hypothesis is developed based on morphological characters and allozyme data, which is then contrasted with a reconstruction based on 1071 nucleotides of mitochondrial DNA (cytochrome b and part of one tRNA gene). Phylogenies derived from the three data sets are largely congruent, although several aspects are supported by only one kind of evidence (but not contradicted by the others). Only with regard to the position of south-east Asian H. leucogaster and its closely related sister species H. sanfordi was there conflict between allozyme and mtDNA data. The position of H. pelagicus relative to H. leucoryphus or H. albicilla/leucocephalus could not be resolved with the mtDNA sequence data, suggesting that some speciation events occurred in relatively quick succession during the early Pliocene or late Miocene periods. Available evidence suggests that extant sea eagles originated at tropical latitudes, the northernmost species appearing most derived.     

多基因联合分析棒束孢属Isaria（Ascomycota,Cordycipitaceae）系统发育关系

对棒束孢属Isaria及近缘属物种开展5基因（nrSSU、nrLSU、tef-1α、rpb1和 rpb2）测序并联合分析,结合GenBank相关类群序列,探讨棒束孢属系统发育关系,最终获得95个菌株、58个明确分类群的2-5基因序列。利用MEGA和MrBayes软件进行多基因聚类分析,结果表明棒束孢属多系起源于虫草菌科中,分3个不同分支。A支主要由Isaria cicadae、I. teniupes、I. coleopterorum、I. fumosorosea和I. cateniannulata等组成;B支包括I. poprawkii、I. locustica、I. javanica、I. amoenerosea和I. cateniobliqua;C支仅有I. farinosa。分支间被Cordyceps militaris、C. ninchukispora、C. pruinosa等隔开。棒束孢在形态上,主要以瓶梗基部膨大、尖端变细及孢子呈链状等特征与其他类群分开,但同时也发现有棒状分生孢子梗和单孢子类型。基于节点的分歧时间预测分析,推测棒束孢属首次分化于70Mya,但棒束孢属主要物种形成却在60-55Mya,且3个分支的棒束孢物种为快速同时形成,而后大多数类群表现遗传稳定。同时发现,与Isaria Clade A较近一支有粉被玛利亚霉Mariannaea pruinosa（C. pruinosa无性型）和蛹草蚧霉Lecanicillium militaris（C. militaris无性型）;与粉棒束孢距离最近一支有Akanthomyces aculeatus（C. tuberculata无性型）和L. attenuatum（C. confragosa无性型）,是两个不同的属征分类群,且相互间遗传距离较近。根据棒束孢属及其近缘种属形态特征的复杂性推测,棒束孢属在快速物种形成中,其近缘类群存在一定程度的丢失和选择性演化。