首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 515 毫秒
1.
Molecular data were used to evaluate the validity of the genus Neopisosoma Haig, 1960. Comparisons of morphological features within Neopisosoma suggest the existence of two lineages, represented among others, by N. angustifrons (Benedict, 1901) and N. neglectum Werding (1986). Both lineages of Neopisosoma are more similar to two morphologically different species groups of the genus Pachycheles, than to congeners of the other group. Comparative morphology of larvae from N. angustifrons, N. neglectum and species of Pachycheles shows that N. angustifrons closely resembles Pachycheles species, whilst N. neglectum is set apart. Sequences of a 465 bp segment of the mitochondrial gene cytochrome oxidase I (COI) were obtained and used to infer phylogenetic relationships among N. angustifrons, N. neglectum, one species of Pachycheles and seven other species of porcellanids, representing three other genera. Results of the molecular analysis were congruent to results of comparative morphological studies of larvae: N. angustifrons grouped with the Pachycheles species, whereas N. neglectum is placed apart. This led us to the conclusion that the genus Neopisosoma is probably paraphyletic and that the criterion used by Haig (1960) is not reliable to define the genus. A revision on a world-wide basis of the genera included, and additional sequence information will be necessary to satisfactorily resolve relationships within the Porcellanidae.  相似文献   

2.
Strain BBS, the purple sulfur bacterium assigned initially to the species Thiocapsa roseopersicina, is the best studied representative of this species. However, no molecular phylogenetic analysis has been performed to confirm its systematic position. Based on the results of analysis of the sequences of 16S rRNA, cbbL, and nifH genes, DNA-DNA hybridization with the T. roseopersicina type strain, and comparative analysis of the phenotypic characteristics of various species belonging to the genus Thiocapsa, we suggest that strain BBS should be assigned to a new species of the genus Thiocapsa, Thiocapsa bogorovii sp. nov. Original Russian Text ? T.P. Tourova, O.I. Keppen, O.L. Kovaleva, N.V. Slobodova, I.A. Berg, R.N. Ivanovsky, 2009, published in Mikrobiologiya, 2009, Vol. 78, No. 3, pp. 381–392.  相似文献   

3.
The leiognathid genus Nuchequula can be defined by the following combination of characters: mouth protruding downward; a narrow band of small, slender, villiform teeth in both jaws; teeth on upper jaw strongly recurved; the lateral line almost complete; a dark blotch on the nape. Although the genus was first established as a subgenus of Eubleekeria, it is here raised to generic level on the basis of the aforementioned morphological characters and recent molecular biological evidence. The genus comprises six valid species: N. blochii (Valenciennes 1835), distributed in India and Thailand; N. flavaxilla sp. nov., occurring only at Panay I., Philippines; N. gerreoides (Bleeker 1851), widely distributed in the Indo-West Pacific, from the Persian Gulf to Cape York, Australia, and north to Taiwan; N. glenysae sp. nov., from northern Australia and Ambon, Indonesia; N. longicornis sp. nov., from the Gulf of Thailand and Indonesia; and N. nuchalis (Temminck and Schlegel 1845), occurring in southern China including Taiwan, and southern Japan. Diagnostic characters of the species belonging to the genus are as follows: N. blochii—breast scaled, cheek naked, and a conspicuous black blotch distally on spinous dorsal fin; N. flavaxilla sp. nov.—breast naked, dorsolateral body surface fully scaled, preorbital spine bicuspid and not expanded distally, and second dorsal and anal fin spines conspicuously elongated; N. gerreoides—breast naked, anterior part of dorsolateral surface of body almost completely scaled, and second dorsal and anal fin spines not conspicuously elongated; N. glenysae sp. nov.—breast completely scaled, cheek scaled, and unique complicated sensory canals present on the suborbital area, extending to the nape; N. longicornis sp. nov.—breast naked, dorsolateral body surface fully scaled, preorbital spine bicuspid or tricuspid and extended distally, and second dorsal fin spines only conspicuously elongated; N. nuchalis—breast naked, anterior part of dorsolateral surface of body widely naked, and a conspicuous dark blotch distally on spinous dorsal fin.  相似文献   

4.
A novel Gram-negative and rod-shaped bacterium, designated N8T, was isolated from tidal flat sediment. Phylogenetic analysis based on 16S rRNA gene sequences showed that N8T strain is associated with the family Phyllobacteriaceae: two uncultured clones (98.4 and 99.8% 16S rRNA gene sequence similarity) and the genus Mesorhizobium (≤97.0%). The novel strain formed a separate clade with uncultured clones in the phylogenetic tree based on 16S rRNA gene sequences. Cellular fatty acid profiles predominately comprised C18:1 ω7c and C19:0 cyclo ω8c. The major isoprenoid quinone is ubiquinone-10 and genomic DNA G+C content is 53.4 mol%. The polyphasic taxonomic study indicates that the novel strain N8T represents a novel species of the new genus in the family Phyllobacteriaceae, named Aliihoeflea aestuarii. The type strain is N8T (= KCTC 22052T= JCM 15118T= DSM 19536T).  相似文献   

5.
Among the isolates from soil of corn and sugar cane plantations in São Paulo State, Brazil, two new species ofNeosartorya, N. botucatensis andN. paulistensis, are described and illustrated.Neosartorya botucatensis differs from the other known species of the genus in having ascospores with long spines on the convex walls.Neosartorya paulistensis is characterized by its ascospore walls with spinose and verruculose ornamentation. The former is compared with the closely related speciesN. spinosa, and the latter is closely related toN. glabra, N. pseudofischeri and N. stramenia.  相似文献   

6.
The genetic diversity of the genus Lespedeza is not well known and the phylogenetic relationship of Lespedeza with the genus Kummerowia is unclear. We report the first study in which polymorphic expressed sequence tag-simple sequence repeat (EST-SSR) markers derived from Medicago, cowpea and soybean were used to assess the genetic diversity of the USDA Lespedeza germplasm collection and clarify its phylogenetic relationship with the genus Kummerowia. Phylogenetic analysis partitioned 44 Lespedeza accessions into three main groups some of which were species-specific and eight subgroups. This data set revealed some misidentified accessions, and indicated that the two species in the genus Kummerowia are closely related to the genus Lespedeza. Morphological reexamination was used to correct the misidentified accessions within the genus Lespedeza. Our results demonstrated that phylogenetic analysis with morphological reexamination provides a more complete approach to classify accessions in plant germplasm collection and conservation.  相似文献   

7.
Taphrina entomospora is one of the few species of the genus described on native plants of the Southern Hemisphere and also one of the few leaf pathogens known on Nothofagus species. The anatomical changes it produces on N. pumilio leaves, and its morphology, cytology, and sporogenesis were studied. The fungus is a perennial species that overwinters as mycelium in the foliar buds and infects the developing leaves, so the whole blade develops the disease symptoms. Interveinal areas of the leaves become chlorotic, thickened and rounded. Palisade parenchyma fails to develop, with spongy parenchyma developing as packed, rounded, isodiametric cells with little intercellular space. The mycelium is subcuticular, dikaryotic, and produces ascogenous hyphae, asci, and ascospores as described for other species in the genus. Before ascus discharge, ascospores bud in a regular, unique way. The life-cycle of T. entomospora is compared with other representative taxa in the genus and the distribution of this pathogen is discussed.  相似文献   

8.
The relationship between Litsea and related genera is currently unclear. Previous molecular studies on these taxa using cpDNA and nrITS were unable to produce well-resolved phylogenetic trees. In this study, we explored the potential of the rpb2 gene as a source of molecular information to better resolve the phylogenetic analysis. Although rpb2 was believed to be a single-copy gene, our cloning results showed that most species examined possessed several copies of these sequences. However, the genetic distance among copies from any one species was low, and these copies always formed monophyletic groups in our molecular trees. Our phylogenetic analyses of rpb2 data resulted in better resolved tree topologies compared to those based on cpDNA or nrITS data. Our results show that monophyly of the genus Litsea is supported only for section Litsea. As a genus, Litsea was shown to be polyphyletic. The genera Actinodaphne and Neolitsea were resolved as monophyletic groups in all analyses. They were also shown to be sisters and closer to the genus Lindera than to the genus Litsea. Our results also revealed that the genus Lindera is not a monophyletic group.  相似文献   

9.
10.
The Middle East is at the southeastern borderline of the range of the subterranean amphipod Niphargus. The review of new and published data identified two new species and set the guidelines for the future research in the area. The genus in this part of the world seems to be insufficiently studied. The taxonomic status of Niphargus valachicus, population identified as N. spoeckeri and some populations, identified as N. nadarini, need to be reviewed. According to present data, we expect the highest diversity in Western Turkey. The eventual new records of the genus in the Middle East can be expected from those areas where even the longest periods of drought in the recent geological history did not affect the water supply.  相似文献   

11.
Physical mapping of plastid DNA variation among eleven Nicotiana species   总被引:1,自引:0,他引:1  
Summary Plastid DNA of seven American and four Australian species of the genus Nicotiana was examined by restriction endonuclease analysis using the enzymes Sal I, Bgl I, Pst I, Kpn I, Xho I, Pvu II and Eco RI. These endonucleases collectively distinguish more than 120 sites on N. tabacum plastid DNA. The DNAs of all ten species exhibited restriction patterns distinguishable from those of N. tabacum for at least one of the enzymes used. All distinctive sites were physically mapped taking advantage of the restriction cleavage site map available for plastid DNA from Nicotiana tabacum (Seyer et al. 1981). This map was extended for the restriction endonucleases Pst I and Kpn I. In spite of variation in detail, the overall fragment order was found to be the same for plastid DNA from the eleven Nicotiana species. Most of the DNA changes resulted from small insertions/deletions and, possibly, inversions. They are located within seven regions scattered along the plastid chromosome. The divergence pattern of the Nicotiana plastid chromosomes was strikingly similar to that found in the genus Oenothera subsection Euoenothera (Gordon et al. 1982). The possible role of replication as a factor in the evolution of divergence patterns is discussed. The restriction patterns of plastid DNA from species within a continent resembled each other with one exception in each instance. The American species N. repanda showed patterns similar to those of most Australian species, and those of the Australian species N. debneyi resembled those of most American species.Abbreviations ims isonuclear male sterile - ptDNA plastid chloroplast DNA - Rubisco ribulosebisphosphate carboxylase/oxygenase - kbp kilobase pairs - LSU large subunit of Rubisco  相似文献   

12.
A cladistic analysis of the genusAnisopappus (Asteraceae: Inuleae) has been undertaken. A hypothesis of species interrelationships in the genus is presented for the first time. The analysis also includedArctotis (Arctoteae), used as outgroup, and five additional genera from theInuleae: Geigeria, Calostephane, Asteriscus, Buphthalmum, Pulicaria, andInula. It is concluded thatAnisopappus is a monophyletic group situated at the base of the tribe, diagnosed by, e.g., their obtuse stylar sweeping-hairs. The species with acute sweeping-hairs were found to be derived within the genus. Problems concerning species delimitation, biogeography and character evolution in the genus are briefly discussed.  相似文献   

13.
魏江春  姜玉梅 《菌物学报》1989,8(Z1):135-150
关于子囊菌亚门石耳科的属级分类问题地衣学家持有不同的观点。这些观点使属级分类出现了单属系统,二属系统,三属系统以及四属系统与五属系统。现在新二属系统,即石耳属一疱脐衣属系统已被越来越多的地衣学家和子囊菌学家所接受。但是,因为由Dodge (1968)描述的单种属拉诺属(Llanoa)的模式种与早已为人熟知的网脊石耳很相似,而近年来,这一单种属又被一些作者所接受、因此、我们不得不对该属模式种所依据的原始材料进行必要的复查。复查结果表明,拉诺属的模式种卖为网脊石耳的异名。因此,拉诺属也就成为石耳属的异名。此外,基于石耳科中三十五种地衣和五十二项特征的聚类分析结果也支持新的二属系统。  相似文献   

14.
Cassia L. sensu lato, a large heterogeneous genus of flowering plants, occurs naturally in the tropics around the world. Recent works based on floral morphology have supported a division of this genus into three genera, namely Cassia L. s. str., Chamaecrista Moench and Senna Mill. In order to investigate this new classification, 508 specimens of 18 taxa of the genus Cassia s.l. grown in Thailand were analyzed using cluster analysis and canonical discriminant analysis. The total 32 vegetative and reproductive morphological characters were employed in these analyses. In cluster analysis, Cassia s.l. can be separated into four groups, respectively viz. Chamaecrista, Senna alata, Senna and Cassia s /str. The four-cluster grouping is discussed. From a canonical discriminant analysis using the four-cluster grouping as a priori groups, it can be concluded that Cassia s. str., Senna, and Chamaecrista are indeed distinct taxa. The three most important characters that separate the three genera are filament length, fruit length, and ovary stalk length. These quantitative characters, together with some qualitative characters, were useful in constructing an identification key to these genera. Among the three genera, it was also found that Senna is rather a heterogeneous taxon. The difference between the studied species was discussed.  相似文献   

15.
In this paper we describe the isolation and characterization of a temperate cyanophage N(S)1 of the genus cyanopodovirus which produces turbid plaques on the host Anabaena 77S15 isolated from tropical soil. Its properties have been compared to those of other well-characterized cyanophages. In addition, two strains of Anabaena 77S15 lysogenic for N(S)1 were isolated. N(S)1 seems to be integrated into the chromosome of the two lysogens, and a 2 kb plasmid present at a low copy number in the non-lysogenic strain is amplified significantly.  相似文献   

16.
A phylogenetic analysis of selected symbiotic Nostoc strain sequences and available database 16S rDNA sequences of both symbiotic and free-living cyanobacteria was carried out using maximum likelihood and Bayesian inference techniques. Most of the symbiotic strains fell into well separated clades. One clade consisted of a mixture of symbiotic and free-living isolates. This clade includes Nostoc sp. strain PCC 73102, the reference strain proposed for Nostoc punctiforme. A separate symbiotic clade with isolates exclusively from Gunnera species was also obtained, suggesting that not all symbiotic Nostoc species can be assigned to N. punctiforme. Moreover, isolates from Azolla filiculoides and one from Gunnera dentata were well nested within a clade comprising most of the Anabaena sequences. This result supports the affiliation of the Azolla isolates with the genus Anabaena and shows that strains within this genus can form symbioses with additional hosts. Furthermore, these symbiotic strains produced hormogonia, thereby verifying that hormogonia formation is not absent in Anabaena and cannot be used as a criterion to distinguish it from Nostoc.The GenBank accession numbers for the cyanobacterial 16S rRNA gene sequences determined in this study are AY742447-AY742454.  相似文献   

17.
Nitokra humphreysi sp. nov. (Harpacticoida: Ameiridae) is described from anchialine ground waters of the Cape Range karst area in northwestern Australia. The new species belongs to those species of the genus Nitokra Boeck, 1865 with a reduced number of spines/setae on the basoendopodite of the female fifth leg. It is remarkably similar to N. reunionensis Bozic, 1969 and to N. laingensis Fiers, 1986, but there are clear distinguishing features. Nitokra humphreysi sp. nov. has clear stygomorphic features, being colourless and lacking the nauplius eye.  相似文献   

18.
Recent systematic studies ofBartsia andOdontites showed the necessity to exclude the closely related perennial speciesBartsia aspera (Portugal and northern Morocco) andBartsia spicata (Central Pyrenees) from the genusBartsia as a segregate genus namedNothobartsia. Morphologically this new genus combines characteristic features ofBartsia and ofOdontites. Its autonomous systematic position is supported by the cladistic analysis, showing thatNothobartsia represents a relatively primitive genus standing close to the common ancestral root ofBartsia, Euphrasia, andOdontites.  相似文献   

19.
拟孢囊菌属(Kibdelosporangium)是一个经典的丝状放线菌类群。自Shearer等于1986年建立该属以来,不断有新的菌株从不同生境中被纯培养分离得到,目前已有效发表8个种、2个亚种。拟孢囊菌属作为稀有放线菌属,是获得新型抗生素类次生代谢产物的重要资源。本文结合我们分离到的一株该属菌株的功能研究、基因组分析和相关文献资料,系统综述了拟孢囊菌属放线菌的建立、分类学特征、属内种的分布、活性次级代谢产物的发现以及其他功能应用和开发前景,以期为该属其他新分离菌株的分类鉴定、新颖次级代谢产物的发现、功能基因资源的挖掘与开发提供借鉴。  相似文献   

20.
A new poecilopsettid flounder, Nematops nanosquama, is described from 10 specimens (4 males, 6 females) collected from deep waters (96–650 m) off Hiva Oa, Marquesas Islands. This species is easily separated from the three recognized species of the genus Nematops by having large numbers of dorsal fin rays, anal fin rays, lateral line scales, and vertebrae, five dark transverse broad bands on the body, and a black blotch on the distal area of the pectoral fin. N.nanosquama shows the easternmost record of this genus from the Pacific Ocean.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号