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 31 毫秒
1.
BackgroundAll the currently recognized Malassezia species have been isolated from mammals. However, only a few of them have been isolated from birds. In fact, birds have been less frequently studied as carriers of Malassezia yeasts than mammals.AimIn this study we describe two new taxa, Malassezia brasiliensis sp. nov. and Malassezia psittaci sp. nov.MethodsThe isolates studied in this publication were isolated from pet parrots from Brazil. They were characterized using the current morphological and physiological identification scheme. DNA sequencing and analysis of the D1/D2 regions of the 26S rRNA gene, the ITS-5.8S rRNA gene sequences and the β-tubulin gene were also performed.ResultsThe strains proposed as new species did not completely fit the phenotypic profiles of any the described species. The validation of these new species was supported by analysis of the genes studied. The multilocus sequence analysis of the three loci provides robust support to delineate these species.ConclusionsThese studies confirm the separation of these two new species from the other species of the genus Malassezia, as well as the presence of lipid-dependent Malassezia yeasts on parrots.  相似文献   

2.
3.
ABSTRACT

Background: According to modern coexistence theory, ecologically similar species can coexist if fitness differences between them are small, or niche differences between them are large. However, these predictions have not been tested extensively in real systems and are difficult to examine in traits-based studies.

Aims: The aim of our study was, by using the carnivorous pitcher plant genus Nepenthes as a model system, to examine (1) species growth ranks as a proxy for fitness; (2) modern coexistence theory at a geographical scale; (3) evidence for pitcher trait-mediated resource partitioning between sympatric Nepenthes species.

Methods: We used growth ranks, obtained from a survey of experienced Nepenthes nursery owners, as a proxy for fitness. Multivariate pitcher-, vegetative- or combined-trait distances, computed from morphometric-trait data from the literature were used as proxies for niche differences. Data on global Nepenthes species-pair sympatry was modelled against these fitness and niche differences.

Results: Niche and growth rate differences were positively and negatively correlated with sympatry, respectively, as expected from theory.

Conclusion: Our results agree with theory and suggest that fitness differences can be approximated from average species growth. Prey- and microhabitat-resource partitioning, operating through divergent pitcher and vegetative traits respectively, are likely mechanisms that stabilise the coexistence of sympatric Nepenthes species.  相似文献   

4.

The cosmopolitan subfamilies Aphrodinae, Jassinae, Xestocephalinae, Idiocerinae, and Macropsinae are diagnosed and the New Zealand species described and illustrated. Each subfamily is represented in New Zealand by only one or two species, those in Idiocerinae having been introduced from Europe or North America. The species Euacanthella brunnea Evans (Aphrodinae) is synonymised with the Australian species E. insularis Evans (new synonymy).  相似文献   

5.
Until now, two species of Borgatomelissa Patiny, 2000 have been described, both from loci typici located in the Near East and eastern Africa. Borgatomelissa brevipennis (Walker, 1871), the most widespread taxon, has also been found in the southern Sahelo-Sudanian belt of the Sahara. A third species from eastern Morocco is described in the present study: Borgatomelissa flavimaura n. sp. In addition to taxonomic insights, the new species sheds a new light on the biogeography of the genus.  相似文献   

6.
Background: Tropical rainforests represent the most species-rich and at the same time the most fragmented terrestrial biome on Earth. Fragmentation of tropical rainforests is having wide-ranging consequences for the maintenance of local species diversity and community assembly patterns.

Aims: To examine floristic changes and changes in community phylogenetic structure in the forest fragment over the past five decades.

Methods: A new taxonomic diversity algorithm (within-family diversity) was developed to assess floristic changes in the forest fragment. Community phylogenetic structure was then compared before and after fragmentation.

Results: Taxonomic diversity changed greatly among families, with changes occurring randomly across the phylogeny. The forest fragment had higher phylogenetic diversity, higher mean pair-wise phylogenetic distance, but lower mean nearest-neighbour distance. The community phylogenetic structure has changed significantly from clustering to dispersion.

Conclusions: High species turnover occurred in the forest fragment. While shade-tolerant species have been lost, and ruderal and alien species have been added, overall phylogenetic diversity has increased with species being more phylogenetically distant. Competitive exclusion, which was related to the relatively drier conditions in the forest after fragmentation, led the plant community phylogenetic structure to be more dispersed.  相似文献   

7.
David J. Hearn 《Brittonia》2007,59(4):308-327
Four new species and one new combination ofAdenia are presented, along with a vegetative key and diagnostic characters of the Madagascan species. Additional notes are provided about unusual specimens and field observations.Adenia kigogoensis from Tanzania is shown to be distinct fromA. stenodactyla (its putative closest relative) andA. digitata based on anther connation and other floral traits. The remaining new taxa are from Madagascar.Adenia litoralis has been observed from one coastal locality in northern Madagascar. It is distinctive in fruit size and leaf form.Adenia metamorpha is the only Madagascan taxon with a narrow cylindrical trunk and large napiform tuber; it is also known from only one locality in Madagascar in the Ankarana Reserve.Adenia mcdadiana is a robust liana with highly reduced glands and leaves that appear to be neotenic compared to its closest putative relative,A. sphaerocarpa. Finally, the position ofA. stylosa has been clarified. This species was once treated asA. firingalavensis var.stylosa, and prior to that asA. epigea var.stylosa, but molecular and morphological data suggest it is separate from these species.  相似文献   

8.
Capsule?Of 26 species of wintering waterbirds, 18 showed an increase in numbers, five showed a decrease and two showed no change.

Aim?To assess long-term trends in the numbers and distribution of the 26 most abundant wintering waterbird species in the Czech Republic.

Methods?We used International Waterbird Census data from between 48 and 639 wetland sites which had been counted annually in the Czech Republic from 1966 to 2008. From these data long-term changes in numbers and distributions were determined. Log-linear Poisson regression analysis was used to estimate missing data using trim software. The distribution of each species was described as the ratio of the number of sites occupied by that species to the total number of sites investigated.

Results?Increasing trends were found for 18 species, five species were found to be declining, one species was stable and two species were found with uncertain trends. Wintering distributions (the ratio of sites occupied by a given species to the total number of sites counted) increased in 16 species and decreased in two species, broadly correlated with the species changes in numbers.

Conclusion?In most species changes in numbers as well as changes in distribution followed the Western Palearctic population trends. Those species which increased were mainly piscivores and included geese, ducks and gulls. Scarcer species also exhibited an increase in numbers. The changes in numbers (both positive and negative) were more frequent among species associated with running water, whereas species which showed uncertain trends were more frequently recorded on standing water, which is more affected by variable weather conditions.  相似文献   

9.
The copper(II) complexes with ciprofloxacin (CFLH), levofloxacin (LFLH), norfloxacin (NFLH), and neutral bidentate ligands have been synthesized and characterized. The complexes have been evaluated for their antibacterial activity against selective species. Complexes have been also checked for their interacting behavior with DNA, and were found to have two different modes of interaction, classical and partial intercalation. Tested complexes were found to be better antioxidants with their IC50 values ranging from 0.51 to 0.97 μM.  相似文献   

10.
11.
12.
Amaranths are an important group of plants and include grain, vegetable and ornamental types. Despite the economic importance of the amaranths, there is very little information available about the extent and nature of genetic diversity present in the genus Amaranthus at molecular level. We now report the randomly amplified polymorphic DNA (RAPD) profiles of different species of Amaranthus as well as different accessions of the species. These RAPD analyses have been carried out using 65 arbitrary sequence decamer primers. From the RAPD data, an UPGMA dendrogram illustrating the inter-as well as intra-species relationships has been computed. The putative hybrid origin of A.dubious from A. hybridus and A. spinosus is also ruled out by the RAPD data. The trends of species relationships amongst the amaranths determined by RAPDs is consistent with their cytogenetic and evolutionary relationships that have already been determined. NBRI Communication No:464 (N.S.).  相似文献   

13.
We describe four new species of Ruellia from Costa Rica; three from the Osa Peninsula, Puntarenas province (R. exilis, R. mira, R. odorata), and one from the southwestern corner of San José province (R. norvegigratiosa). Ruellia matagalpae is reported as a new record for the country. New combinations are made in Ruellia for the two Costa Rican species of Blechum (R. blechum and R. costaricensis). Three species are reduced to synonymy, and another species is considered doubtfully worthy of recognition. Notable range extensions are reported for two species. Corollas and fruits of all 22 Costa Rican species of Ruellia are shown and compared as easily used identification aids. An informal guide to species groups and a dichotomous key to the 22 species are presented.  相似文献   

14.
《Plant Ecology & Diversity》2013,6(3-4):447-455
Background: High-altitude ecosystems in the Alps have experienced severe environmental changes over the past decades, such as strong warming and increasing numbers of visitors and grazers. Few studies have followed the effects of such changes on the alpine flora over a period longer than a few decades. The summit of Piz Linard (3410 m, south-eastern Switzerland) is the oldest site in the Alps whose flora has been recorded, on average every 20 years since the Little Ice Age (1835).

Aims: We re-surveyed the summit flora of Piz Linard to trace its floristic changes and identify their patterns and possible drivers.

Methods: We mapped each species' highest location, distribution and abundance in the uppermost 30 m of the Piz Linard summit in 2011, and compared species composition and species’ altitudinal distribution over time.

Results: Species richness increased at an accelerated rate since 1992 and rose from 12 to 16 species since the previous record in 2003. Most already present species increased in abundance and colonised new areas of the summit, while new arrivals mainly established at sites with already high species richness. Species appeared after 1992 differed from species already present previously by having had lower maximum altitudes elsewhere in south-eastern Switzerland.

Conclusions: Temporal and spatial patterns of colonisations and former altitudinal ranges of species all point to climate warming as the principal driver of floristic change on Piz Linard.  相似文献   

15.
This paper describes two new species, Trypeticus fissirostrum n. sp. from Hainan and Trypeticus yunnanensis n. sp. from Yunnan Provinces, China. Three Trypeticus species having been recorded in the territory of China before this study, their total number in this country has now increased to five. A key to the Chinese species is compiled and given in the text. The type specimens are deposited in Institute of Zoology, Chinese Academy of Sciences.  相似文献   

16.
Background and aimsThe tribe Danaideae (Rubiaceae) is almost exclusively endemic to the Western Indian Ocean Region (WIOR), and encompasses the genera Danais, Payera and Schismatoclada that occur in humid, sub-humid and mountain and mountain bio climate zones. Much of the species diversity is endemic to restricted, remote and/or mountainous areas of Madagascar and recent field work on the island indicates substantial unknown diversity of the Danaideae. Furthermore, the monophyly of the Malagasy genera Payera and Schismatoclada has been questioned in previous work, species delimitations and phylogenetic relationships within the genera are poorly understood, and the distribution and evolution of gross morphological features have not been assessed.MethodsWe conducted morphological investigations, and produced robust phylogenies of Danaideae based on nuclear and plastid sequence data from 193 terminals. Ample plant material has been newly collected in the WIOR for the purpose of the present study, including potentially new species unknown to science. We performed Bayesian non-clock and relaxed-clock analyses employing three alternative clock models of a dataset with a dense sample of taxa from the entire geographical ranges of Danaideae. Based on the results, we discuss species diversity and distribution, relationships, and morphology in Danaideae.Key resultsOur results demonstrate the monophyly of Danaideae, its three genera and 42 species. Nine species are resolved as non-monophyletic. Many geographically distinct but morphologically heterogeneous lineages were identified, and morphological features traditionally considered diagnostic of subgroups of the genera, used for example in species identification keys, are not clade-specific.ConclusionsOur results demonstrate that Madagascar contains ample previously undocumented morphological and species diversity of Danaideae. Our novel approach to molecular phylogenetic analyses as a precursor to taxonomic revisions provides numerous benefits for the latter. There are tentative indications of parallel northward diversification in Payera and Schismatoclada on Madagascar, and of geographical phylogenetic clustering despite the anemochorous condition of Danaideae.  相似文献   

17.
ABSTRACT

The brightly blue shallow water species Terpios fugax Duchassaing and Michelotti, 1864 was originally described from the Caribbean and has been extensively recorded in the Atlantic Ocean, but rarely found in the Indian and Pacific Oceans. In the Pacific Ocean it has been only reported from Sulawesi, Indonesia and from the Caroline and Marshall Islands. Here we report the first record of Terpios in the Eastern Pacific, based on the presence of T. fugax at Caldera, Región de Atacama, northern Chile. Although this species may have been inadvertently introduced to the area by human activity, it should also be considered that the geographically distant populations of this sponge (from the Caribbean to the Eastern Pacific) may represent different species.  相似文献   

18.

Plesiochorus Looss, 1901 is a genus of Gorgoderidae infecting the urinary bladders of marine turtles globally. Currently, just two morphologically similar species are recognised, Plesiochorus cymbiformis (Rudolphi, 1819) Looss, 1901 and Plesiochorus elongatus Pigulevsky, 1953, which have been distinguished by molecular data and subtle morphological differences. Here we describe a new species, Plesiochorus irwinorum n. sp., infecting hawksbill turtles (Eretmochelys imbricata (L.)), which is primarily distinguished from the other two species of Plesiochorus on the basis of ITS2, cox1 and 28S sequence data. Morphometric data for specimens examined during this study overlap between P. cymbiformis and P. irwinorum n. sp. for every measured feature, rendering them functionally cryptic. However, principal components analysis clearly distinguishes the two species. Additionally, we report new specimens of P. cymbiformis, and provide new sequence data for specimens from Australian loggerhead (Caretta caretta (L.)) and hawksbill turtles. There is little understanding of the host-specificity or geographical distribution of the three species of Plesiochorus, and it remains possible that some of the previously reported sequences have been attributed to the wrong species.

  相似文献   

19.
BackgroundNontuberculous mycobacteria (NTM) have been reported to be increasing worldwide and its geographic distribution differs by region. The aim of this study was to describe the epidemiology and distribution of NTM in the eastern part of China.MethodsSputum samples were collected from 30 surveillance sites for tuberculosis drug resistance test from May 1, 2008 to December 31, 2008. Identification was performed using a biochemical test, multiplex PCR and GenoType Mycobacterium CM/AS assay.ResultsA total of 1779 smear positive clinical isolates were obtained, of which 60 (3.37%) were NTM. Five species/complex of NTM were identified; M. intracellulare was the predominated species (68.33%), followed by M. abscessus-M. immunogenum (13.33%), Mycobacterium spec. (10.00%), M. Kansasii (6.67%) and M. peregrinum-M. alvei-M. septicum (1.67%).Conclusion M. intracellulare was the main species of NTM in the eastern part of China and clinical physicians should pay more attention to NTM induced pulmonary disease.  相似文献   

20.
[背景] 在陕西省的毛泡桐腐木桩上观察和采集到一株绒毛状真菌子实体,编号为HMNWAFU-CF-HS002。[目的] 为了确定该菌的分类地位,对其进行形态观察及分子鉴定。[方法] 获取宏观彩色图像并对显微结构进行测量、统计和绘图。此外,用PDA培养基分离纯化该菌的培养物,并结合最大似然法、最大简约法和贝叶斯法进行rDNA ITS分子系统学研究。[结果] HMNWAFU-CF-HS002的形态特征与Punctularia atropurpurascens高度相似。系统发育分析将HMNWAFU-CF-HS002聚在P.atropurpurascens的单系分支中。[结论] 结合形态学特征与系统发育结果,HMNWAFU-CF-HS002被鉴定紫黑点壳菌(Punctularia atropurpurascens),为中国的新记录种。此外,毛泡桐为其新记录寄主。至此,Punctularia属下的3个种,均在中国有分布记录。  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