中国基干鸟类综述

"基于鸟类(basal birds)"为一种类数量相对较少的化石鸟类,基干鸟类较另一鸟类群--"鸟胸类(Ornithothoraces)"原始;鸟胸类(包括现生鸟类和反鸟类)为一类种类数量很大、具有同一祖先、且来源于基干鸟类的鸟类群.在过去的15年里,共有产自中国的8个属、12个有效种基干鸟类发表,而产自的德国的始祖鸟为唯一的非中国产基干鸟类;当然,孔子鸟化石也发现于朝鲜.本文对产自中国的基干鸟类的形态学、系统发生和生态学进行了简单的综述.中国的化石材料对科学地了解鸟类的早期演化具有重要意义,揭示了基干鸟类个体相对较大、形态特征和生态环境变异也相对较大等特点.尽管有些明显的不确定因素的存在(例如热河鸟、会鸟和中鸟的相对系统关系存有争议),但是由于中国化石材料的存在,鸟类早期演化的真实场景已经愈加清晰.     

基于线粒体基因cyt b和COI的莺科部分鸟类系统发育

雀形目(Passeriformes)莺科(Sylviidae)鸟类广泛分布于旧大陆,该科许多种类的系统发育关系一直存在争议.本研究采用分子系统学方法,对莺科11属37种鸟类的cyt b全基因序列和COI部分基因序列进行系统发育分析,构建TML和Bayesian系统发育树.结果显示,柳莺属(Phylloscopus)并非单系发生,(鹟)莺属(Seicercus)可能是其同类或其属下的一个类群;在柳莺属内,乌嘴柳莺(P.magnirostris)与极北柳莺(P. borealis)亲缘关系较近;黄腰柳莺(P.proregulus)、云南柳莺(P.yunnanensis)、橙斑翅柳莺(P. pulcher)及灰喉柳莺(P. maculipennis)亲缘关系较近;黄腹柳莺(P.occisinensis)、巨嘴柳莺(P.schwarzi)、棕眉柳莺(P. armandii)、叽喳柳莺(P. collybita)及褐柳莺(P.fuscatus)亲缘关系较近;树莺属(Cettia)并非单系发生,与拟鹅莺属(Abroscopus)和地莺属(Tesia)聚在一起;大苇莺属(Acrocephalus)为单性系;此外,林莺属(Sylvia)与绣眼鸟属(Zosterops)的亲缘关系、以及鹪莺属(Prinia)、缝叶莺属(Orthotomus)及扇尾莺属(Cisticola)三者间的亲缘关系也被支持.     

European species of Hypocrea: Part I. The green-spored species

At present 75 species of Hypocrea have been identified in temperate Europe. Nineteen green-spored species and their Trichoderma asexual states are here described in detail. Extensive searches for Hypocrea teleomorphs in 14 European countries, with emphasis on Central Europe, yielded more than 620 specimens within five years. The morphology of fresh and dry stromata was studied. In addition, available types of species described from Europe were examined. Cultures were prepared from ascospores and used to study the morphology of cultures and anamorphs, to determine growth rates, and to extract DNA that was used for amplification and sequencing of three genetic markers. ITS was used for identification, while RNA polymerase II subunit b (rpb2) and translation elongation factor 1 alpha (tef1) were analyzed for phylogenetic reconstruction of the genus.Several unexpected findings resulted from this project: 1) The previous view that only a small number of Trichoderma species form a teleomorph is erroneous. 2) All expectations concerning the number of species in Europe are by far exceeded. Seventy-five species of Hypocrea, two species of Protocrea, and Arachnocrea stipata, are herein identified in temperate Europe, based on the ITS identification routine using fresh material, on species described earlier without molecular data and on species recently described but not collected during this project. 3) Current data suggest that the biodiversity of Hypocrea / Trichoderma above soil exceeds the number of species isolated from soil. 4) The number of Trichoderma species forming hyaline conidia has been considered a small fraction. In Europe, 26 species of those forming teleomorphs produce hyaline conidia, while 42 green-conidial species are known. Three of the detected Hypocrea species do not form an anamorph in culture, while the anamorph is unknown in four species, because they have never been cultured.This work is a preliminary account of Hypocrea and their Trichoderma anamorphs in Europe. Of the hyaline-spored species, H. minutispora is by far the most common species in Europe, while of the green-spored species this is H. strictipilosa.General ecology of Hypocrea is discussed. Specific associations, either with host fungi or trees have been found, but the majority of species seems to be necrotrophic on diverse fungi on wood and bark.The taxonomy of the genus will be treated in two parts. In this first part 19 species of Hypocrea with green ascospores, including six new teleomorph and five new anamorph species, are described in detail. All green-spored species belong to previously recognised clades, except H. spinulosa, which forms the new Spinulosa Clade with two additional new species, and H. fomiticola, which belongs to the Semiorbis Clade and forms effuse to large subpulvinate stromata on Fomes fomentarius, a trait new for species with green ascospores. Anamorph names are established prospectively in order to provide a basis for possible policy alterations towards their use for holomorphs.Taxonomic novelties: Hypocrea aeruginea Jaklitsch, Trichoderma aerugineum Jaklitsch, T. dacrymycellum Jaklitsch, H. danica Jaklitsch, H./T. fomiticola Jaklitsch, H. longipilosa Jaklitsch, H./T. parepimyces Jaklitsch, H. parestonica Jaklitsch, T. parestonicum Jaklitsch.     

The Leptosphaeria maculans – Leptosphaeria biglobosa species complex in the American continent

Stem canker of oilseed rape (canola, Brassica napus ) is associated with a species complex of two closely related fungal species, Leptosphaeria maculans and L. biglobosa . Of these, L. maculans is the most damaging and develops gene-for-gene relationships with the host . Here, a wide scale analysis of the L. maculans - L. biglobosa species complex was performed throughout the American continent (23 locations from Chile to Canada) plus several locations in Western Australia for comparison purposes, based on a collection of 1132 isolates from infected tissues of a susceptible cultivar. Fungal species were discriminated on the basis of morphological, phytopathological and molecular criteria and showed that L. biglobosa was closely associated with L. maculans in most of the locations. Multiple gene phylogeny using sequences of ITS, actin and β-tubulin confirmed the prevalence of the L. biglobosa 'canadensis' sub-clade in Canada, whereas up to three different sub-clades of L. biglobosa were found in Georgia (USA). Race structure of L. maculans was investigated using a combination of pathogenicity tests and PCR amplification of avirulence alleles AvrLm1 , AvrLm4 and AvrLm6 . Three contrasting situations were observed: (i) race structure in Ontario, Chile and Georgia was related to that of European and Western Australian populations, with a low race diversity; (ii) only one race was found in Mexico, and not found outside of this country; (iii) a large diversity of races was observed in central Canada (Manitoba, Alberta and Saskatchewan) with very specific features including maintenance of avirulence alleles absent from Europe, absence of the AvrLm7 allele common in Europe (or eastern Canada) and wide location-to-location variability.     

Morphological and molecular characterization of <Emphasis Type="Italic">Oidium</Emphasis> subgenus <Emphasis Type="Italic">Reticuloidium</Emphasis> (powdery mildew) newly occurred on cucumber in Japan

In 2002, a powdery mildew with catenate conidia lacking fibrosin bodies was found on cucumber in a greenhouse in Kanagawa Prefecture, Japan. Morphological observation revealed that the fungus belongs to Oidium subgenus Reticuloidium, anamorph of the genus Golovinomyces. Molecular phylogenetic analyses of the nucleotide sequences of the rDNA ITS regions and D1/D2 domains of the 28S rDNA indicated that the fungus belongs to the clade of G. orontii with other Golovinomyces fungi from a wide range of host plants, suggesting that the fungus was newly transported from abroad. Because there has been no prior report of cucumber powdery mildew caused by Reticuloidium, further research on the physiology, epidemiology, control and resistant cucumber varieties is required.     

The complete mitochondrial genome of Rondotia menciana (Lepidoptera: Bombycidae)

The mulberry white caterpillar, Rondotia menciana Moore (Lepidoptera: Bombycidae) is a species with closest relationship with Bombyx mori and Bombyx mandarina, and the genetic information of R. menciana is important for understanding the diversity of the Bombycidae. In this study, the mitochondrial genome (mitogenome) of R. menciana was amplified by polymerase chain reaction and sequenced. The mitogenome of R. menciana was determined to be 15,301 bp, including 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes, and an AT-rich region. The A+T content (78.87%) was lower than that observed for other Bombycidae insects. All PCGs were initiated by ATN codons and terminated with the canonical stop codons, except for coxII, which was terminated by a single T. All the tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The length of AT-rich region (360 bp) of R. menciana mitogenome is shorter than that of other Bombycidae species. Phylogenetic analysis showed that the R. menciana was clustered on one branch with B. mori and B. mandarina from Bombycidae.     

Genetic diversity within two Tunisian wild jirds: Meriones shawi and Meriones libycus (Rodentia,Gerbillinae)

Three Meriones species inhabit Tunisia, namely M. shawi, M. libycus and M. crassus, but little genetic data exist on these gerbils. We collected Meriones from eight localities in Tunisia, and obtained mitochondrial (cytochrome b) and nuclear (IRBP) gene sequence data for 37 and 13 specimens, respectively, belonging to two species: M. shawi and M. libycus. We also optimised three microsatellite markers previously described in M. unguiculatus to obtain a finer analysis of their genetic diversity and geographic structure, given their wide distribution. Phylogenetic inferences of cyt b and IRBP data for these species, in the context of other gerbillin data, corroborate their taxonomic affinities reported by previous studies. High cyt b haplotype diversity was observed in both species (25 haplotypes in 29 and 27 sequences for M. shawi and M. libycus, respectively) with little geographical structure for M. shawi but three divergent groups in M. libycus. The average microsatellite diversity within each population was high (H_O ≥ 0.6, H_E ≥ 0.8) with M. libycus populations attaining the highest values. Population differentiation was moderate for several population pairs (F_st ≥ 0.1), the highest being between M. shawi populations. However, genetic distance among populations was not significantly correlated with geographic distance in either M. shawi or M. libycus. Our results contribute to a better characterisation of Tunisian Meriones species, suggesting high geographic structure in mtDNA of M. libycus populations within North Africa.     

Evidence of multiple divergent mitochondrial lineages within the southern African diplopod genus Bicoxidens Attems, 1928 (Spirostreptida)

Two recent studies have suggested that divergent mitochondrial lineages may be present within spirostreptid genera such as Bicoxidens Attems, 1928. Bicoxidens, similar to many other endemic soil invertebrates, exhibits low dispersal capabilities and strict microclimate habitat preferences, attributes that often lead to geographic isolation. Given that prolonged geographic isolation often lays the foundation for population genetic differentiation, genetic divergence and possibly speciation, there was good reason to suspect that Bicoxidens may consist of several distinct lineages. On this basis, the mitochondrial cytochrome c oxidase subunit 1 (COI) was used to reconstruct the phylogeny of Bicoxidens and reveal divergent lineages within the genus. Maximum likelihood and Bayesian inference analyses recovered a paraphyletic Bicoxidens phylogram with divergent lineages present in three species – B. friendi, B. flavicollis and B. brincki – suggesting high genetic diversity within the genus. Bayesian genetic cluster analyses suggested the presence of multiple distinct mitochondrial lineages within the genus with four identified in B. flavicollis alone. It was therefore concluded that the divergent lineages observed among Bicoxidens populations may suggest the presence of hidden species.     

无花果树苗中截获的无花果孢囊线虫形态和分子鉴定

上海口岸从旅客携带进境的树苗中分离到1种孢囊线虫属的2龄幼虫,通过形态特征和分子特征分析,鉴定为无花果孢囊线虫(Heterodera fici Kirjanova,1954)。该2龄幼虫的主要形态特征为:体长409.9~454.4μm;唇环3个;口针发达,长22.6~24.0μm,基部球圆形略向前倾斜;侧线4条;尾长圆锥形,末端细圆,尾部透明区长24.7~30.5μm,约占尾长的1/2。序列分析显示其ITS区序列与GenBank中无花果孢囊线虫的序列相似性为99.48%~99.90%,序列差异为1~5 bp。系统发育分析显示该线虫与无花果孢囊线虫处于一个聚类组内。这是我国口岸首次报道截获无花果孢囊线虫。