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1.
Asexual and sexual morphs of powdery mildews on Fontanesia phillyreoides and Jasminum fruticans, two hitherto unknown host species, have recently been collected in Turkey. Analyses of morphological traits and molecular sequence data led to identifications of the causal agents of the powdery mildew diseases involved. Fontanesia phillyreoides was infected by Phyllactinia fraxini, and the powdery mildew on Jasminum fruticans can be classified as Erysiphe cf. aquilegiae. The latter host showed traces of a co-infection with a second powdery mildew (only asexual morph) belonging to the genus Phyllactinia (= Ovulariopsis) and morphologically well agreeing with P. fraxini.  相似文献   

2.
Paravannella minima n. g. n. sp. (Amoebozoa, Vannellidae) isolated from a freshwater aquarium, possesses all light-microscopic and ultrastructural characteristics of the genus Vannella, being one of the smallest species among the vannellid amoebae (cell size during locomotion usually between 4.5 and 10 μm). At the same time, sequence analysis of the genes encoding for nuclear SSU rRNA, actin and mitochondrial Cox1 shows this species as the earliest-branching vannellid that appears to be sister to the rest of this clade. This is correlated with the presence of some plesiomorphic characters; in particular, the secondary structure of the hypervariable helices E23-1–E23-7 in the studied species is shared with Vannella and most of the genera of Dactylopodida. The cell coat structure of the studied species corresponds to the hypothesis that vannellid amoebae were ancestrally enclosed in a cell coat consisting of pentagonal glycostyles that have undergone multiple independent losses in various clades of Vannellidae.  相似文献   

3.
4.
A new genus and species of Euptychiina (Satyrinae), Cristalinaia vitoria Mota, Zacca & Freitas gen. et sp. nov., is described based on three specimens collected in the region of the Cristalino River, Alta Floresta, Mato Grosso, Brazil. This rare species is known only from this region, where it flies inside the dense bamboo patches typical of that area. The last instar larva and the pupa are described; the larva was observed feeding on mature leaves of the common bamboo Guadua aff. paniculata Munro.urn:lsid:zoobank.org:pub:D61EDE8D-CAE9-41C6-B24D-BB789873566E  相似文献   

5.
陈静  蒋万祥  沈琦  谢志才 《生态学报》2015,35(8):2461-2472
线蚓科隶属于环节动物门环带纲,迄今共记录32属650余种,是该纲的第二大科。它们广泛分布于土壤、海洋、淡水、河口和冰川等。其中,约2/3的线蚓科物种(近500种)为陆生种类,100余种仅分布在海洋中。尽管经历了200多年的探索,线蚓科仍然是认知最少的类群之一。尝试回顾人类对线蚓科环带动物分类学和系统发育学方面的认知历程和积累的知识体系,描述线蚓科关键的形态学分类特征以及线蚓科分类研究遇到的主要问题和障碍,展望了线蚓科分类学未来的研究方向。线蚓科的分类研究尚处于α分类阶段,体现在以物种探索为主和大量的已描述的物种需要验证等。而基于生物学物种概念(生殖隔离)的线蚓科物种探索,虽然有一些合理的逻辑解释,但缺乏严格的科学验证。线蚓科内多数属为复系,表明已建立的线蚓科分类系统仍然不能很好的反映线蚓科的自然进化历史。线蚓科分类面临的主要问题和障碍是未描述种类亟待发掘、已描述的物种需要验证、属/种的厘定以及现代属级概念的建立、DNA分类在线蚓科的应用和线蚓科内的系统发育关系研究亟待开展,以及物种探索的不平衡、经费和研究人才匮乏以及网络分类的缺失等。将分子学数据和系统发育物种概念纳入线蚓科的分类学研究,应该是线蚓科分类的一个方向。通过解读保守基因的信息,可以揭示线蚓科的祖先与它们生活的古环境长期斗争的历史,以及将优良的性状遗传给后代的过程和驱动力。而系统发育物种概念认为物种是拥有共同祖先的,物种仅能通过生殖隔离与系统发育重建一起加以验证。基于系统发育物种概念而构建的线蚓科分类系统,必将能真实的反映线蚓科内各分类单元的亲缘关系和进化轨迹。而将最新的线蚓科分类学知识传播于分类学知识的终端使用者,是线蚓分类学家的职责。这些知识将有助于提高人们对线蚓类在生态系统中功能的了解,如土壤有机质分解、养分矿化和健康评价以及评估气候变化等。  相似文献   

6.
Following taxonomic revisions in recent years, the originally large family Grapsidae MacLeay, 1838 has become a relatively small and morphologically homogeneous family in terms of adult and larval morphology. Most available molecular studies including more than one genus of the family have also suggested monophyly of the corresponding taxa. However, no single phylogenetic study has ever included all constituent genera of the Grapsidae. In the current study, a molecular phylogeny based on sequences of the mitochondrial 16S rRNA gene from all eight grapsid genera and 34 species is presented and suggests that up to four genera are not monophyletic. This is mainly due to the polyphyletic nature of the genus Pachygrapsus which can be found in six different lineages of the phylogeny, suggesting that the genus currently does not represent a single evolutionary lineage and is in need of taxonomic revision. Amphi-atlantic and trans-isthmian species pairs or populations in four genera are compared and reveal relatively constant and pronounced divergences across the Panama Isthmus as opposed to moderate divergences across the Atlantic Ocean, thereby suggesting occurrence of gene flow across the Atlantic Ocean during the past three million years.  相似文献   

7.
中国柳莺属鸟类分类研究进展   总被引:1,自引:1,他引:1  
柳莺属(Phylloscopus)是广泛分布于旧大陆地区的小型食虫鸟类,目前全世界已知66种,其中约50种见于亚洲。该属鸟类外部形态十分相近且同域分布种数较多,历来是鸟类分类学中的研究难点及热点。2003年贾陈喜等介绍了20世纪90年代以来发表的分布于我国的柳莺属鸟类新种及相关分类学变动,涉及3个新描述种和9个由亚种提升的种,共计30种26亚种。2003年以来关于柳莺属鸟类的分类学研究取得了许多新的成果,同时我国境内也发现了一些新的分布记录。综合最新的文献及分布资料,整理得知我国现有柳莺属鸟类41种31亚种,与2003年的状况相比已有较大的变化。主要表现在:新描述种方面,德国学者Martens等2008年描述了黄腹柳莺(P.affinis)种组中的一新种———华西柳莺(P.occisinensis);2010年瑞典学者Alstrm等报道在越南和老挝地区新发现的灰岩柳莺(P.calciatilis)已被证实在我国有分布;亚种提升为种方面,如日本柳莺(P.xanthodryas)自极北柳莺(P.borealis)中独立,冠纹柳莺(P.claudiae)和西南冠纹柳莺(P.reguloides)分开等;分类地位再评议方面,如灰头鹟莺(Seicercusxanthoschistos)实为灰头柳莺(P.xanthoschistos)等;新分布纪录方面,如欧柳莺(P.trochilus)在内蒙古达里诺尔湖地区发现确切记录等。现今对柳莺属鸟类分类学方面的研究已明显呈现出传统形态学、分子遗传学、声谱分析及野外鸣声回放实验等新老技术手段相整合,多方面多角度地阐述问题的局面。中国是世界柳莺属鸟种分布最多的国家(其中有9种仅在或主要于我国境内繁殖),但我国鸟类学者关于该属鸟类的研究工作并不多见。柳莺属鸟类在分类学和进化生物学等领域具有重要的研究价值,我国鸟类学工作者应当引起足够的重视和关注。  相似文献   

8.
The genera Parasesarma and Perisesarma are common inhabitants of mangroves and estuaries of the Indo-West Pacific. These, overall similar, genera of sesarmid crabs can be told apart by the presence or absence of an anterolateral tooth, but recent and ongoing studies show that they are not reciprocally monophyletic. In recent years, detailed morphological studies have revealed a surprising number of undescribed new species within these genera. In the present paper, we describe a new species of the genus Parasesarma from the relatively poorly studied Persian Gulf. So far, these specimens had been referred to as Parasesarma plicatum (Latreille, 1803), but morphological and genetic characteristics clearly allow separation of the two species. Consequently, the species from the Persian Gulf is here described as new and morphological and mitochondrial genetic characters are provided that allow recognition of the species.  相似文献   

9.
Pseudocerastium is a monotypic genus in Caryophyllaceae endemic to China. The genus has been widely accepted since it was described in 1998, however its phylogenetic position within Caryophyllaceae has never been studied. In the present study, the whole plastid genome and nuclear ribosomal internal transcribed spacer (ITS) sequences of Pseudocerastium stellarioides was obtained through genome skimming, and the phylogenetic position of the species was studied for the first time. Plastid phylogenomic analysis of Caryophyllaceae revealed that Pseudocerastium is clustered within the tribe Alsineae with strong support. Phylogenetic analyses based on an enlarged taxon sampling of Alsineae using five DNA regions (matK, rbcL, rps16 intron, trnL-F and ITS) revealed that P. stellarioides was nested deeply within Cerastium with strong support. Analyses of morphological character evolution suggest that the ancestral states in Alsineae include three styles and a six-lobed capsule at the apex, while both Cerastium and Pseudocerastium have five styles and ten lobes at the apex of the capsule, further supporting their close relationship. The species Pseudocerastium stellarioides is similar to Cerastium wilsonii in morphology, but differs in having villous indumentum on the lower part of the filaments and compressed globose seeds. Therefore, based on the present molecular and morphological evidence, the generic name Pseudocerastium is reduced here as a new synonym of Cerastium and the species P. stellarioides is transferred to Cerastium as C. jiuhuashanense.  相似文献   

10.
To test the hypothesis that host-switching can be an important step in the speciation of gyrodactylid monogenean flatworms, we inferred the phylogeny within a cluster of parasites morphologically close to Gyrodactylus salaris Malmberg 1957, collected from Atlantic, Baltic and White Sea salmon (Salmo salar), farmed rainbow trout (Oncorhynchus mykiss), and grayling (Thymallus thymallus) from Northern Europe. The internal transcribed spacer region of the nuclear ribosomal gene was sequenced for taxonomic identification. Parasites on grayling from the White Sea Basin differed from the others by one nucleotide (0.08%), the remainder were identical to the sequence published earlier from Norway (G. salaris on salmon), England (Gyrodactylus thymalli on grayling), and the Czech Republic (unidentified salaris/thymalli on trout). For increased resolution, 813 nucleotides of the mitochondrial COI gene of 88 parasites were sequenced and compared with 76 published sequences using phylogenetic analysis. For all tree building algorithms (NJ, MP), the parasites formed a star-like phylogeny of six definite sister clades, indicating nearly simultaneous radiation. Average K2P distances between clades were 1.8-2.6%, and internal mean distances 0.2-1.1%. The genetic distance to the nearest known relative, Gyrodactylus lavareti Malmberg, was 24%. A variable salmon-specific mitochondrial Clade I was observed both in the Baltic Basin and in pathogenic populations introduced to the Atlantic and White Sea coasts. An invariable Clade II was common in rainbow trout farms in Sweden, Denmark and Finland; the same haplotype was also infecting salmon in a landlocked population in Russian Karelia, and in Oslo fjord and Sognefjord in Norway. Four geographically vicariant sister clades were observed on graylings: Clade III in the Baltic Sea Basin; Clade IV in Karelian rivers draining to the White Sea; Clade V in Norwegian river draining to Swedish lake V?nern; and Clade VI in rivers draining to Oslo fjord. The pattern fitted perfectly with the postglacial history of grayling distribution. Widely sampled clades from salmon and Baltic grayling had basal haplotypes in populations, which were isolated early during the postglacial recolonisation. The divergence between the six clades was clear and linked with their hosts, but not wide enough to support a species status for them. Parasites from the Slovakian type population of G. thymalli were not available, so this result does not mean that G. salaris and G. thymalli are synonyms. It is suggested that the plesiomorphic host of the parasite cluster was grayling, and the switch to salmon occurred at least once when the continental ice isolated Baltic salmon in an eastern freshwater refugium, 130,000 years ago. At the same time, parasites on grayling were split geographically and isolated into several allopatric refugia. The divergence among the parasite clades allowed a tentative calibration of the evolutionary rate, leading to an estimate of the divergence of 13.7-20.3% per million years for COI coding mtDNA. The results supported the hypothesis that parallel to the allopatric mode, host switch and instant isolation by host specificity can be operated as a speciation mechanism.  相似文献   

11.
A taxonomic study of the genus Zeadolopus Broun in Korea is presented. Two species, Zeadolopus chaosicus Daffner and Z. japonica (Champion), are recognized and the latter is recorded for the first time in Korea. A key, diagnoses, and illustrations of diagnostic characters are provided.  相似文献   

12.
刘少英  靳伟  唐明坤 《兽类学报》2020,40(3):290-301
䶄亚科田鼠族(Microtini)是一个分布广、物种多、在分类学上存在争议也较多的类群。通常认为该族在全世界有10属81种,中国有7属24种。近年来,通过广泛采集标本,开展分类与系统发育研究,基本厘清了我国䶄亚科田鼠族分类与系统发育问题。确认田鼠族在全世界仅8属,分别是东方田鼠属(Alexandromys)、雪田鼠属(Chionomys)、毛足田鼠属(Lasiopodomys)、艾草田鼠属(Lemmiscus)、田鼠属(Microtus)、松田鼠属(Neodon)、沟牙田鼠属(Proedromys)和川西田鼠属(Volemys)。帕米尔田鼠属(Blanfordimys)被证明是田鼠属的亚属,白尾松田鼠属(Phaiomys)是松田鼠属 的同物异名,水䶄属(Arvicola)被证明不属于田鼠族。而东方田鼠属是从田鼠属的亚属提升为属。中国田鼠族包括6属26种。青海毛足田鼠(Lasiopodomys fuscus)、白尾松田鼠(Phaiomys leucurus)和克氏田鼠(Microtus clarkei)均是松田鼠属成员。凉山沟牙田鼠(Proedromys liangshanensis)、林芝松田鼠(Neodon linzhiensis)、聂拉木松田鼠(Neodon nyalamensis)和墨脱松田鼠 (Neodon medogensis)是近年来命名的新种。  相似文献   

13.
The second internal transcribed spacer (ITS2) of nuclear ribosomal DNA from 73 specimens of Astigmata was analyzed by PCR amplification and DNA sequencing. The length of the ITS2 region varied from 282 to 592 bp. The interspecific variation based on consensus sequences was more than 4.1%, while the intraspecific or intra-individual variation was from 0 to 5.7%. The variation between geographically separated populations (0–3.2%) was almost the same as the variation within strains. The sequences of the ITS2 region of Astigmata were concluded to be species-specific. The phylogenetic tree inferred from the ITS2 region supported Zachvatkins morphological classification in the subfamily Rhizoglyphinae. The species-specific ITS2 sequence is useful for the species identification of astigmatid mites and for studying low-level phylogenetic relationships.Chemical Ecology of Astigmatid Mites LXXVThis revised version was published online in May 2005 with a corrected cover date.  相似文献   

14.
In Aspleniaceae,Hymenasplenium is a well-defined group with dorsiventral creeping rhizomes. Members ofHymenasplenium are widely distributed in the tropic zones of the world and have great variation in morphology and ecolgy, making it a good model group for plant systematics and evolutionary biology. I have worked on this group using techniques such as comparative morphology, ecology, cytology (for examining chromosomes and reproductive modes), phytochemistry and molecular biology. I considered the evolution of various phenetic characters based on a molecular phylogenetic tree which I recently obtained from sequence comparisons ofrbcL. In this paper, I will summarize the results. Recipient of the Botanical Society Award for Young Scientists, 1993.  相似文献   

15.
The taxonomic framework of the Haploporidae is evaluated and the relationships within the Haploporinae are assessed for the first time at the generic level using molecular data. Partial 28S and complete ITS2 rDNA sequences from representatives of six of the nine recognised genera within the Haploporinae were analysed together with published sequences representing members of two haploporid subfamilies and of the closely related family Atractotrematidae. Molecular analyses revealed: (i) a close relationship between the Atractotrematidae and the Haploporidae; (ii) strong support for the monophyly of the Haploporinae, Dicrogaster and Saccocoelium, and the position of Ragaia within the Haploporinae; (iii) evidence for rejection of the synonymy of Saccocoelioides and Lecithobotrys and the validity of the Dicrogasterinae; and (iv) support for the distinct status of Saccocoelium in relation to Haploporus. The wider sampling within the genera Dicrogaster and Saccocoelium confirmed the distinct status of the included species, thus rejecting previously suggested synonymies. Saccocoelioides, recently transferred to the Chalcinotrematinae, was nested within the Haploporinae and this was largely associated with the position of Forticulcita, resolved as the most basal haploporine genus. Forticulcita also possesses a well-delimited eversible intromittent copulatory organ, a feature unique in the Haploporidae which has not been previously considered an important apomorphy. This, in association with the present hypothesis of the Haploporinae based on molecular data, led us to erect Forticulcitinae subf. n. for Forticulcita; this resolved Saccocoelioides and, by extension the Chalcinotrematinae, as sister groups to the Haploporinae.  相似文献   

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18.
郭玉红 《动物学杂志》2023,58(2):307-317
钝头蛇属(Pareas)蛇类形态高度保守,种间形态差异微弱。以分子系统学方法为中心的整合分类方法的应用,为本类群分类难题的解决作出了重要贡献,近8年有9个新种得以描述,其中,仅在近3年就增加了7个新种,并有6个同物异名被恢复。本文依据最新研究成果,对近期钝头蛇属蛇类系统分类研究成果进行了综述,并斟酌中文种名,整理了物种名录,并编制了分类检索表。截止目前,钝头蛇属共有26种,其中在我国有分布的18种,中国特有种9种。同时,对研究中存在的问题进行了探讨,并对下一步工作提出了建议:本属物种多样性估计过低、标本采集覆盖范围不足、证据使用不甚全面,大范围密集采样以及系统发育基因组学方法的应用有助于本类群系统关系的最终解决。  相似文献   

19.
Ten species of Sargassum (Sargassaceae, Phaeophyceae) were found along the Gulf of Thailand. Morphological characteristics of Sargassum baccularia (Mertens) C.A. Agardh, S. binderi Sonder, S. cinereum J.G. Agardh, S.crassifolium J.G. Agardh, S. longifructum Tseng et Lu, S. oligocystum Montagne, S. polycystum C.A. Agardh, S. siliquosum J.G. Agardh, S. swartzii (Turner) C.A. Agardh and one unidentified species were examined and are described in detail. The most common species were S. polycystum distributed widely in almost all the study sites, S. crassifolium restricted to Prachuap Khirikhan Province, S. longifructum restricted to Chumphon Province, S. siliquosum restricted to Surat Thani Province and one unidentified species restricted to Songkhla Province. Three species (S. cinereum, S. longifructum and S. swartzii) are new records for the algal flora of Thailand. Five species (S. baccularia, S. cinereum, S. longifructum, S. polycystum and the unidentified species) belong to the section Zygocarpicae (J.G. Agardh) Setchell.  相似文献   

20.
In this study we describe, the first microsporidian parasite from nephropid lobsters. Metanephrops challengeri were captured from an important marine fishery situated off the south coast of New Zealand. Infected lobsters displayed an unusual external appearance and were lethargic. Histology was used to demonstrate replacement of skeletal and other muscles by merogonic and sporogonic stages of the parasite, while transmission electron microscopy revealed the presence of diplokaryotic meronts, sporonts, sporoblasts and spore stages, all in direct contact with the host sarcoplasm. Analysis of the ssrDNA gene sequence from the lobster microsporidian suggested a close affinity with Thelohania butleri, a morphologically dissimilar microsporidian from marine shrimps. Whilst morphological features of the lobster parasite are consistent with members of the family Nosematidae, molecular data place the parasite closer to members of the family Thelohanidae. Due to the contradiction between morphological and molecular taxonomic data, we propose the erection of a new genus in which the lobster parasite is the type species (Myospora metanephrops). Furthermore, we recommend the erection of a new family (Myosporidae) and a new order (Crustaceacida) to contain this genus. The taxonomic framework presented could be further applied to the re-classification of existing members of the Phylum Microsporidia.  相似文献   

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