基于ITS和trnL-F序列鉴定边陲黄耆为独立的物种

乌拉特黄耆(Astragalus hoantchy Franch.)、边陲黄耆(A.dshimensis Gontsh.)和A.coluteocarpus Bioss.为形态上相似的3个近缘物种。为了明确它们之间的分子亲缘关系,探讨分子证据是否支持边陲黄耆为一个独立的物种,测定了这3个物种共33个样本的ITS和trn L-F序列。基于ITS+trn L-F联合序列,运用Mega 6.06软件计算了种内和种间的遗传距离,并利用Mega 6.06和Mr Bayes 3.2软件分别构建了最大似然(ML)树和贝叶斯(BI)树。结果显示:乌拉特黄耆、边陲黄耆和A.coluteocarpus Bioss.的种内平均遗传距离分别为0.000、0.001和0.003;乌拉特黄耆和边陲黄耆之间平均遗传距离为0.010,而这2个物种与A.coluteocarpus Bioss.之间的平均遗传距离分别为0.015和0.016;乌拉特黄耆和边陲黄耆种间的平均遗传距离远大于其物种内的遗传距离;ML树和BI树具有相似的拓扑结构,均分成了3个分支,其中每个物种的所有个体都聚集在一个单独的分支上且不存在种间交叉现象。本研究揭示了这3个近缘物种的分子亲缘关系,分子证据说明边陲黄耆应该是一个独立的种。     

A phylogenetic perspective on biodiversity patterns of Afrotropical freshwater crabs (Crustacea,Decapoda, Potamonautidae)

1. Evolutionary‐based measures of biodiversity play an increasingly important role in theoretical conservation biology, complementing more traditional methods such as patterns of species richness and endemicity.
2. To date, very few studies have used evolutionary data to assess patterns of biodiversity in the Afrotropical region, particularly for freshwater invertebrate taxa.
3. In the present study, the monophyletic Afrotropical freshwater crab family Potamonautidae was used to investigate how phylogenetic data can be combined with other metrics to help develop conservation plans for regional and species‐based conservation efforts.
4. The Afrotropical freshwater crabs make an exceptional group to demonstrate the utility of a phylogeny‐based approach to conservation, as there have recently been a number of phylogenetic studies on this family, the IUCN Red List conservation status is available for almost every species, and accurate distributional range data are available for all species.
5. The conservation priority of this fauna is assessed in relation to the Afrotropical freshwater ecoregions using three traditional measures of biodiversity and two phylogenetic diversity metrics.
6. The results of Evolutionarily Distinct Globally Endangered and Heightened Evolutionary Distinctiveness and Globally Endangered analyses identify both the freshwater crab species and the areas of high conservation priority in the Afrotropical region.

     

山东省危害核桃的链格孢属真菌鉴定及其系统发育

为了明确危害核桃的链格孢属Alternaria真菌种类,对34个供试菌株在PCA培养基上的培养特征、产孢表型、分生孢子特征等进行了研究,并采用ITS、OPA2-1和OPA1-3序列分析其系统发育。其中33个菌株为链格孢A.alternata,1个为细极链格孢A.tenuissima。链格孢:菌落灰色;孢子链短、分枝频繁,每条分枝含4～10个孢子;分生孢子多倒梨形,孢身平均25.6μm×7.4μm,横隔膜2～8个。细极链格孢:菌落褐色;孢子链长、少分枝,孢子链约含10个孢子;分生孢子多长椭圆形,孢身平均26.3μm×13.5μm,具柱状喙及假喙,主横隔膜1～6个,孢身中部的隔膜较粗。链格孢属真菌在遗传上有较大差异,ITS、OPA2-1和OPA1-3序列对链格孢小孢子种具有一定的区分作用,链格孢是危害核桃的主要链格孢属种。     

Meta‐analysis of growth rates for a circumpolar fish,the northern pike ( Esox lucius), with emphasis on effects of continent,climate and latitude

For circumpolar species, little is known on how somatic growth rates can vary at large, transcontinental spatial scales. In this study, a meta‐analysis of growth rates was conducted for northern pike ( Esox lucius) across North America and Eurasia. Growth rates of northern pike did not differ between North American and ‘coastal Eurasian’ pike (e.g., UK, Ireland, Sweden), while growth rates for both of these groups were significantly higher compared to ‘inland Eurasian’ pike (mainly in Russia). There was no difference in growth between lentic and lotic habitats on either continent. In North America, pike growth was positively correlated with temperature, but in Eurasia, pike growth correlated poorly with most climatic variables. Similarly, maximum longevity in pike populations was significantly predicted by latitude in North America, but not in Eurasia. After standardising annual pike growth by the thermal opportunity for growth, a highly significant countergradient growth relationship was found for North American pike, while a significant, but considerably less predictive countergradient growth relationship was found for Eurasian pike. This study provides novel insights into the ecology of a circumpolar species and how populations function at extraordinarily large spatial scales. First, pike appear to be cosmopolitan across hydrologic habitats having fast or slow growth in either lentic or lotic environments. Secondly, continental‐scale differences in pike growth rates are suggestive of major genetic and life‐history differences. Finally, variable climate–growth relationships and countergradient growth patterns indicate that global climate change is likely to affect circumpolar fishes like pike in complex, nonlinear ways.     

Pathogenic and genetic variability among Colletotrichum lindemuthianum isolates of different geographic origins

The pathogenic and genetic diversity of Colletotrichum lindemuthianum isolates collected from a total of 10 Central and South American, European and African countries were characterized using common bean differential cultivar pathogenicity tests and amplified fragment length polymorphism (AFLP) analysis. On the basis of pathogenicity tests, 74 isolates were attributed to 30 different pathogenic races using the CIAT-defined binary race-classification system. Twenty-one races were restricted geographically, being exclusive to different countries. Race 9 was the most widespread, being detected in four different countries. Cluster analysis of consensus AFLP data generated using three selective AFLP primer combinations grouped 86 isolates (including the 74 subjected to pathogenicity tests) into three clusters (with one isolate as an outlier). This analysis showed that the majority of South and Central American isolates were divided among two clusters, and that the limited number of European and African isolates used in this study were genetically most similar to Central American isolates. Overall, the results of this research showed some associations between the genetic diversity of the isolates and their country of origin, but not between genetic diversity and race classification of isolates.     

Multi-gene phylogenies define Ceratocystiopsis and Grosmannia distinct from Ophiostoma

Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and β-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However, these species are retained in Ophiostoma until further data for a larger number of species can be obtained to confirm monophyly of the apparent lineages.Taxonomic novelties: Ceratocystiopsis manitobensis (J. Reid& Hausner) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., Cop. parva (Olchow. & J. Reid) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., Cop. rollhanseniana (J. Reid, Eyjólfsd. & Hausner) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., Grosmannia abiocarpa (R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. aenigmatica (K. Jacobs, M.J. Wingf. & Yamaoka) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. americana (K. Jacobs& M.J. Wingf.) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. aurea (R.C. Rob. & R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. cainii (Olchow. & J. Reid) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. clavigera (R.C. Rob. & R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. crassivaginata (H.D. Griffin) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. cucullata (H. Solheim) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. davidsonii (Olchow. & J. Reid) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. dryocoetidis (W.B. Kendr.& Molnar) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. europhioides (E.F. Wright & Cain) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. francke-grosmanniae (R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. galeiformis (B.K. Bakshi) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. grandifoliae (R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. huntii (R.C. Rob.) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. laricis (K. van der Westh., Yamaoka & M.J. Wingf.) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. leptographioides (R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. olivacea (Math.-Käärik) Zipfel, Z.W. de Beer& M.J. Wingf. comb. nov., G. pseudoeurophioides (Olchow. & J. Reid) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. radiaticola (J.-J. Kim, Seifert, & G.-H. Kim) Z.W. de Beer & M.J. Wingf. comb. nov., G. robusta (R.C. Rob. & R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. sagmatospora (E.F. Wright & Cain) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. vesca (R.W. Davidson) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov., G. wageneri (Goheen & F.W. Cobb) Zipfel, Z.W. de Beer & M.J. Wingf. comb. nov.     

从分子系统学角度分析拟盘多毛孢属及其近缘属的界限

拟盘多毛孢属和截盘多毛孢属的划分界限长期以来因分类学家的观点不一致而处于模糊状态，以核糖体DNA的内转录间区序列建立分子系统树的结果支持五细胞分生孢子类型应归入拟盘多毛孢属，四细胞分生孢子类型应归入截盘多毛孢属，分子系统树同时可以反映无性阶段和有性阶段之间的联系，显示出分子系统学对形态分类学的客观性的评判作用。     

Tan spot of pyrethrum is caused by a Didymella species complex

Tan spot is a disease of pyrethrum (Tanacetum cinerariifolium) in Australia. Recent increases in the severity and incidence of the disease have prompted a re‐evaluation of the pathogen, originally described as Microsphaeropsis tanaceti, including its phylogenetic relationships and morphology. Nucleotide comparison of partial sequences of the nuclear ribosomal internal transcribed spacer, β‐tubulin, large subunit 28S nrDNA (LSU), actin and glyceraldehyde‐3‐phosphate dehydrogenase loci identified two distinct haplotypes within the species. Haplotype differentiation was consistent for each locus, except for the LSU, within which sequences were identical across all isolates. Morphological variation, especially culture pigmentation and conidial size, consistently supported the phylogenetic data distinguishing two haplotypes. Phylogenetic comparisons of M. tanaceti incorporating 98 Didymellaceae species did not associate the M. tanaceti haplotypes with the genus Microsphaeropsis. The two M. tanaceti haplotypes were closely related, and clustered in the Didymella sensu stricto clade. Based on these phylogenetic results, supported by their distinct morphology and cultural characteristics, the two haplotypes of M. tanaceti are reclassified as two species of Didymella, namely D. rosea and D. tanaceti. The implications of two closely related species causing tan spot of pyrethrum are discussed.     

中国部分农区作物上本地烟粉虱隐种的鉴定

烟粉虱Bemisia tabaci是一个至少包括36个不同隐种的物种复合体,为明确中国本地烟粉虱隐种的分布,采用线粒体COI基因(mt COI)分子标记法对2011—2012年在中国27个省(市)61个烟粉虱种群中获得的45个非B/Q隐种烟粉虱个体进行了隐种鉴定和分析,并利用邻接法基于mt COI序列构建了本地烟粉虱隐种的系统发育树。结果显示:45个非B/Q隐种烟粉虱对应的45条线粒体COI序列中共有10个单倍型,所有单倍型分别属于烟粉虱Asia II 2、Asia II 6、Asia II 7、Asia I与China1隐种,均为我国本地隐种。其中,在安徽省发现烟粉虱Asia II 2和China1隐种,在福建省发现Asia II 6和China1隐种,在海南省发现Asia II和Asia I隐种,在广东省发现Asia II 7隐种,在江西省发现China1隐种。表明中国部分农区作物上仍然存在少量的本地烟粉虱。     

禾谷镰刀菌Homeobox基因结构及其演化关系分析

对致病菌禾谷镰刀菌(Fusarium graminearum)全基因组序列中可能的Homeobox基因进行生物信息学分析.结果表明:该菌含有12个可能的Homeobox基因;它们所编码的蛋白都具有同源异型盒结构域,且该结构域中的L15、P28、W51、R56氨基酸残基最保守;所有的同源异型盒结构域蛋白都定位于细胞核中.分子进化分析表明,禾谷镰刀菌Homeobox基因在进化过程中出现分支,并且其分支早于真核生物的分化.研究结果将为深入分析该基因家族的生物学功能奠定基础.