木霉属Trichoderma组和Pachybasium组的分子系统学研究

对来源不同的木霉及其有性型Longibrachiatum组、Trichoderma 组和Pachybasium组的81个菌株进行了ITS序列测定,并对ITS1序列用PHYLIP程序包中的DNAPARS程序进行系统发育分析。结果表明Trichoderma 组和Pachybasium组的所有菌株可分成两个群(A,B),B群进一步分为4个分支(B1,B2,B3,B4);A群由Trichoderma 组的H. aureoviridis和未鉴定到种的3个Hypocrea菌株构成;B1,B2,B4群均由Pachybasium组菌株构成;B3群由Pachybasium组的T. hamatum、T. strigosum和Trichoderma 组的T. asperellum、T. atroviride、T. koningii、T. viride和Hypocrea菌株T261构成。2个组相互交叉,组间没有明确的区分,进一步证明Pachybasium组是多系的。建议将Trichoderma 组中的T. viride aggr.、T. atroviride、T. koningii归并入Pachybasium组,对Trichoderma 组重新定义。     

木霉属Trichoderma组和Pachybasium组的分子系统学研究*

对来源不同的木霉及其有性型Longibrachiatum组、Trichoderma 组和Pachybasium组的81个菌株进行了ITS序列测定,并对ITS1序列用PHYLIP程序包中的DNAPARS程序进行系统发育分析。结果表明Trichoderma 组和Pachybasium组的所有菌株可分成两个群(A,B),B群进一步分为4个分支(B1,B2,B3,B4);A群由Trichoderma 组的H. aureoviridis和未鉴定到种的3个Hypocrea菌株构成;B1,B2,B4群均由Pachybasium组菌株构成;B3群由Pachybasium组的T. hamatum、T. strigosum和Trichoderma 组的T. asperellum、T. atroviride、T. koningii、T. viride和Hypocrea菌株T261构成。2个组相互交叉,组间没有明确的区分,进一步证明Pachybasium组是多系的。建议将Trichoderma 组中的T. viride aggr.、T. atroviride、T. koningii归并入Pachybasium组,对Trichoder…     

中国新记录巴克斯霉属Backusella的两个分类单元(英文)

最近在中国十个省市发现了一个新记录属——巴克斯霉属Backusella,包括一个种的两个变种,即卷曲巴克斯霉原变种B.circina var.circina和卷曲巴克斯霉改级光孢变种B. circina var. lamprospora stat. nov. ≡ B. lamprospora。文章对这两个变种提供了形态描述和线条图,还提供了属内区分所有可以承认的分类群的检索表。把这两个分类群从种级降为变种级的理由亦有所讨论。ITS rDNA序列分析表明,卷曲巴克斯霉是一个多系类群,与放射毛霉属Actinomucor、毛霉属Mucor和根毛霉属Rhizomucor有着密切的谱系关系。这一结果暗示目前的卷曲巴克斯霉种的概念较大,可称为广义卷曲巴克斯霉B.circina s.l.;如果仅仅依靠分子数据,很有可能给出错误的分类学鉴定结果。     

甘蔗茎内两个内生菌株16S rRNA 序列分析及其生长特性

从两个甘蔗品种GT11和RB86-7515表面灭菌的茎中分离到两株具有固氮活性的菌株,分别编号为B11S和B8S.利用16S rRNA序列分析对其进行鉴定,并对两个菌株的生物学特性进行了比较.结果表明:B11S菌株与Stenotrophomonas maltophili菌株处在同一个分支,其序列与多个Stenotrophomonas maltophili菌株的序列相似性都达到98%以上,菌株B8S与多个土壤杆菌属细菌的序列相似性达到100%;两个菌株在温度31℃、pH为6左右时生长量最高;温度31℃、pH为6.5～7.0时固氮酶活性最高;相同浓度的蔗糖生长量大于葡萄糖,且表达固氮酶活性也最强;添加一定量的氮素有利于细菌生长和固氮酶活性的表达,但随着N含量的增加,抑制作用越来越明显.     

2021年2月深圳市六株境外输入的SARS-CoV-2基因组特征分析

为了解深圳境外输入的新型冠状病毒(SARS-CoV-2)的遗传特征,本研究对2021年2月六株境外输入的SARS-CoV-2毒株进行了高通量测序与基因组序列分析.测序获得的六株SARS-CoV-2毒株基因组长度分别为29 450 nt、28 936 nt﹑28 875 nt、29 855 nt、29 146 nt 和29 528 nt.根据"Pango lineages"分型法,三个来自肯尼亚、南非和柬埔寨的毒株属于B.1.1.7系(VOC-202012/01),一个来自美国的毒株属于B.1.2系(美国谱系),两个来自南非和肯尼亚的毒株属于B.1.351系(20H/501Y.V2).与武汉毒株Wuhan-Hu-1(NC_045512.2)比较,B.1.1.7系毒株的刺突蛋白(S)中发现了多达10个氨基酸的变异,B.1.2系毒株的S蛋白仅发现一个氨基酸的变异,B.1.351系毒株的S蛋白中发现了多达11个氨基酸的变异.来自柬埔寨的一株B.1.1.7系毒株的S蛋白中发现了三个变异(H69S,V70I与Y144V)与另外两个B.1.1.7系毒株中的变异(H69del,V70del与Y144del)不同.六个毒株在ORF1b上都表现出了 P314L的变异,在S蛋白上都表现出了 D614G的变异.2021年2月深圳输入了传染性更强的B.1.1.7英国变异株和B.1.351南非变异株.境外输入的SARS-CoV-2变异株存在引起本地暴发与流行的风险,需持续对境外输入的SARS-CoV-2毒株进行分子监测.     

褶皱臂尾轮虫同胞物种复合类群分类的研究进展

褶皱臂尾轮虫包含复杂的同胞物种,对其分类研究经过了一个长期发展的过程。综述了轮虫分类手段的发展进程,介绍和分析了轮虫特别是褶皱臂尾轮虫同胞物种复合类群分类的研究进展。褶皱臂尾轮虫的L-型和S-型属于B.plicatilis和B.rotundiformis两个物种。这个复合类群中还包括更多的种类,如B.plicatilis sensu stricto、B.ibericus和B.rotundiformis,其中B.plicatilis sensu stricto属于L型,B.ibericus属于SM-型,B.rotundiformis属于SS-型。此类研究丰富了轮虫系统分类学,提高了水域生态调查的准确性。     

每期10题

1.绿色开花植物双受精的正确解释是( )。 A.两个精子分别与两个卵细胞融合; B.两个精子分别与两个极核融合; C.两个精子,一个与卵细胞融合,另一个与一个极核融合; D.两个精子,一个与卵细胞融合,另一个与两个极核融合。 2.蕨类植物、裸子植物和被子植物统称为( )。     

中国部分地区马铃薯寄主上致病疫霉SSR基因型分析

利用两对SSR引物对两个基因座Pi4B和Pi4G进行了PCR扩增,测定了中国部分地区66个致病疫霉Phyophthora infestans(马铃薯晚疫病菌)菌株和2个参考菌株的SSR基因型,并对菌株的基因型进行了鉴定和命名.在被测定的66个致病疫霉菌株中,共产生了7种SSR基因型D-03,D-05,D-06,G-02,H-01,F-01和F-06,其中F-06为本研究新命名的基因型.F-01基因型菌株53个,占总菌株数目的80.3%,该基因型为中国致病疫霉的优势基因型.在对两个基因座Pi4B和Pi4G产生的等位基因统计分析发现基因座Pi4B产生的多样性比Pi4G高.对SSR数据揭示的河北、黑龙江和云南3个不同省份致病疫霉遗传多样性的比较发现,河北省和黑龙江省致病疫霉遗传多样性几乎相同,然而与云南省致病疫霉有较大的遗传差异.此外,发现致病疫霉SSR基因型与其对甲霜灵抗性无相关性.     

阴道微生态评价指标监测下治疗细菌性阴道病

目的 了解BV及RBV患者的阴道微生态被彻底恢复与未被彻底恢复停药后的远期复发率差异.方法 137例BV患者(其中RBV 48例)被随机分成A、B两组.A组67例(其中RBV 19例),B组70例(其中RBV 29例).A组治疗至Amsel正常、Nugent评分≤3分、阴道菌群密集度Ⅱ～Ⅲ度且乳酸杆菌占明显优势、H2O2≥2μmol/L时停药;B组治疗至Amsel正常时停药.A、B两组停药后均随访6个月.结果 A组随访6个月复发率为22.39％、但B组高达63.08％.A组中BV患者随访6个月复发率为18.75％、B组为33.33％.A组中RBV患者随访2个月复发率为31.58％、但B组高达86.21％,随访3个月时B组全部复发.结论 动态监测阴道微生态评价指标,能客观指导临床BV治疗.BV患者、尤其RBV患者经个体化治疗,积极彻底恢复阴道微生态环境,明显降低了其远期复发率.     

应用B.t.和SBTi基因提高水稻抗虫性的研究

用基因枪法将单个B.t.基因或与SBTi基因一起导入到两个华南地区优良籼稻品种中,获得21个转B.t.单基因的植株系,4个转B.t.和SBTi双基因的植株系。对R1代植株的分子杂交和遗传分析表明,3个转双基因系中多个拷贝的B.t.和SBTi基因均是整合在植株基因组同一染色体上相同或相近位点。Northern blot证明在R2代转基因植株中B.t.基因稳定表达。对稻纵卷叶螟的抗性实验表明,转B.t.单基因或B.t.和SBTi双基因的转基因植株均较原种对照有更强的抗性,而转双基因植株较转单基因植株又有更强的抗性。     

Fungal endophytes of proteaceae, with particular emphasis onBotryosphaeria proteae

Fungal endophytes occurring in leaves and stems of three species of Proteaceae,Protea cynaroides, Leucospermum cordifolium andLeucadendron salignum×laureolum were investigated on farms in three locations in the Western Cape province of South Africa. The aims of this study were to determine ifBotryosphaeria proteae, a fungus that has been recorded from leaf spots ofProtea spp., was mostly restricted to leaf tissue, and whether it could occur as an endophyte in different members of Proteaceae. In this studyB. proteae was routinely isolated inProtea andLeucospermum, although it was not a dominant taxon and did not occur inLeucadendron. Botryosphaeria proteae occurred mostly in leaves, rather than stems, suggesting that it is not important as a stem canker pathogen.     

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。     

A new species of Betula section Betulaster (Betulaceae) from China

A new species of Betulaceae, Betula fujianensis , is described and illustrated from Luoboyan Reserve, Fujian Province, south-eastern China. Betula fujianensis is distributed in subtropical evergreen and deciduous broad-leaved mixed forest at elevations above 500 m, mostly as scattered individuals and occasionally as populations alone or with B. luminifera . Betula fujianensis belongs to section Betulaster and differs from other species in general morphology and phenology. A key to all species currently recognized in this section is presented, and the relationships between the new species and its closely related taxa are discussed.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 523–528.     

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.     

Poplar stem blister canker and its control strategies by plant extracts

Stem blister canker is a serious stem disease in the Populus genus in China. The pathogen was confirmed as Botryosphaeria dothidea (Moug. ex Fr.) Ces. et de Not. based on its morphological, pathological and molecular features. Seven selected plant species Artemisia annua, Gleditsia sinensis, Lonicera japonica, Macleaya cordata, Phyllodendron chinense, Polygonum cuspidatum and Scutellaria baicalensis, belonging to different families from China, were extracted with the solvent 95% (v/v) ethanol to yield ethanol extracts which were used to evaluate their antifungal activity against poplar stem canker pathogen by a mycelial radial growth inhibition test. Of them, the extracts of M. cordata, P. cuspidatum and S. baicalensis showed stronger antifungal activity, the median inhibitory concentration (IC₅₀) was 0.3125, 1.0219 and 0.9675 mg ml⁻¹ separately. The control effect of extracts of M. cordata, P. cuspidatum and S. baicalensis on poplar stem canker disease was between 62% and 85%. The inhibitory effect of the extracts indicated the importance of some plant species as possible natural source of fungicidal material.     

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.     

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.