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1.
Seven isolates ofTorulomyces from Asian and Australian soil samples were studied in comparison with known taxa of the genus and withMonocillium indicum, the type species ofMonocillium. Three new species,Torulomyces parviverrucosus, T. laevis, andT. ovatus, are described, andT. brunneus is described as a new combination. Conidial characteristics, especially their shape and surface structure, are useful taxonomic criteria for distinguishing species ofTorulomyces. Monocillium is considered to be a distinct genus.  相似文献   

2.
报道了7个楼梯草属和赤车属植物(荨麻科)新纪录,它们分别为锐齿楼梯草(E. cyrtandrifolium),变黄楼梯草(E. xanthophyllum),对叶楼梯草(E. sinense),宽叶楼梯草(E. platyphyllum),托叶楼梯草(E. nasutum),短叶赤车(P. brevifolia)和华南赤车(P. grijsii)。列出了各个物种的标本引证和地理分布情况。  相似文献   

3.
The phylogeny of the four genera of Aizoaceae subfamily Sesuvioideae (Sesuvium, Cypselea, Trianthema and Zaleya) is elucidated employing internal transcribed spacer (ITS) sequences and 23 morphological characters. Phylogenetic analysis based on ITS sequences and a combined molecular-morphological analysis provide largely congruent results. The monophyly of Sesuvioideae and its close relationship to Aizooideae s.l. and Mesembryanthemoideae is confirmed. Zaleya is placed within Trianthema and Cypselea within Sesuvium by ITS analysis, but in the combined analysis, Zaleya forms an unresolved polytomy with the two Trianthema clades and Cypselea, as well as two Sesuvium species, remain unresolved. Sesuvium sesuvioides and S. hydaspicum, previously treated as synonyms, are closely related, but molecular data do not support conspecifity. The Trianthema triquetra complex needs further intensive study because the African T. triquetra sample is closer to the NE African-Arabian T. sheilae than to Australian samples of T. triquetra. The close relationship of four species of Trianthema (T. patellitecta, T. rhynchocalyptra, T. megasperma, and T. pilosa) from Australia based on molecular data is supported morphologically by the exclusive possession of a well-developed indumentum in these taxa.  相似文献   

4.
邓晓娟  闫兴富  刘建利  刘培贵 《生态学报》2018,38(19):7066-7074
以印度块菌-云南松菌根际土壤细菌为研究对象,研究其种群组成和结构特征。(1)稀释平板法分离得到印度块菌-云南松菌根际土壤细菌的纯培养菌株,对菌株的16S rRNA序列测序分析,对测序的菌株数量和得到的OTUs数量绘制物种累积曲线,当物种累积曲线趋于平缓时,对OTUs进行系统发育分析,揭示可培养细菌的种群组成和结构特征。(2)对印度块菌-云南松菌根际土壤细菌16S rRNA基因的V3—V4区进行高通量测序,分析全部细菌类群的种群组成和结构特征。(1)分离得到菌根际可培养细菌793株,分属于3个属的61个OTUs,其中假单胞菌属(Pseudomonas)序列占总序列的86%,不动杆菌属(Acinetobacter)序列占总序列的9.8%,链霉菌属(Streptomyces)序列占总序列的6.5%。假单胞菌是印度块菌-云南松菌根际土壤可培养细菌的绝对优势类群。(2)高通量测序得到菌根际细菌序列8937条,分属于20个门、198属、2073个OTUs。隶属于变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和酸杆菌门(Acidobacteria)的OTUs占总OTUs的65.9%,变形菌门、放线菌门和酸杆菌门细菌是印度块菌-云南松菌根际土壤细菌的优势细菌。隶属于黄杆菌属(Flavobacterium)、根瘤菌属(Rhizobium)和假黄色单胞菌属(Pseudoxanthomona)的OTUs占总OTUs的33%,黄杆菌属、根瘤菌属和假黄色单胞菌属细菌是印度块菌-云南松菌根际土壤细菌的优势属。印度块菌-云南松菌根际土壤可培养细菌多样性较低,假单胞菌属细菌占据绝对优势地位。印度块菌-云南松菌根际土壤细菌类群具有较高的多样性,物种种类丰富,优势菌群集中。  相似文献   

5.
Fifty-two polysaccharides were isolated from the fermentation systems of Tuber melanosporum, Tuber indicum, Tuber sinense, Tuber aestivum and the fruiting bodies of Tuber indicum, Tuber himalayense, Tuber sinense by elution with an activated carbon column. Polysaccharides from Tuber fermentation system exhibited relatively higher in vitro antitumor activity against HepG2, A549, HCT-116, SK-BR-3, and HL-60 cells than those from Tuber fruiting bodies. All polysaccharides were mainly composed of d-mannose, d-glucose, and d-galactose, which suggested that the polysaccharides from Tuber fruiting bodies and fermentation system have identical chemical compositions. The results of antitumor activity and structural identification indicated that the polysaccharide fractions could promote antitumor activity. Tuber polysaccharides from Tuber fermentation system exhibited relatively higher than that from Tuber fruiting bodies. These results confirm the potential of Tuber fermentation mycelia for use as an alternative resource for its fruiting bodies.  相似文献   

6.
Effects of microhabitat complexity on host foraging by three species of Trichogramma (T. deion, T. ostriniae, and T. pretiosum) were evaluated under simulated stored product conditions. All three species have been considered as potential biological control agents for the Indianmeal moth, Plodia interpunctella, in retail stores and warehouses. Trials were conducted with single naïve female parasitoids in 10-cm Petri dishes that were either empty, contained flour, or contained millet. Empty 15-cm Petri dishes, which served as a surface area control, comprised a fourth treatment. Females were allowed to forage for sentinel egg disks for 2 h, after which percentages of parasitism and egg mortality were computed. In addition, behavioral observations were made on a subset of the trials. Trichogramma deion parasitized more eggs than the other two species in the empty dishes and in the dish containing flour. For T. deion, rates of parasitism and egg mortality were significantly greater in both the small and large empty dishes than in the small dishes containing flour or millet. Parasitism was consistently low for all three species in the grain-filled dishes. Among species, T. ostriniae spent the most time walking, while T. pretiosum was the most sedentary. In addition, T. pretiosum spent significantly more time on the first egg visited compared with subsequent eggs. T. deion may be the best-suited for use as a biological control agent for P. interpunctella. However, the potential negative effects of fine-grain habitat complexity should be taken into account when developing a release protocol for Trichogramma spp.  相似文献   

7.
Phylogenetic relationships, limits of species, and genera within Lycoperdaceae, were inferred by use of ITS and LSU nu-rDNA sequence data. Lycoperdaceae was confirmed as monophyletic, and Mycenastrum corium as a sister taxon to the ingroup. Four major clades were identified and received weak to moderate support and correspond with the genera Lycoperdon, Bovista, Calvatia, and Disciseda. The Lycoperdon clade includes species from Lycoperdon, Vascellum, Morganella, Handkea, Bovistella, and Calvatia. The structure within the Lycoperdon clade is unresolved and several clades are more or less unsupported, which suggests treating the supported Lycoperdon clade as the genus Lycoperdon. L. nigrescens and L. caudatum occur on single branches and their phylogenetic positions could not be resolved. The phylogenetic analyses identified 31 species of Lycoperdon, 11 species of Bovista, six species of Calvatia, and two species of Disciseda. In Lycoperdon three new species were recognized. A new species closely related to B. limosa is identified and discussed. A classification of Lycoperdaceae is proposed based on the results of the phylogenetic analyses. Morphological characters of species within and among identified clades are discussed.  相似文献   

8.
In black cotton uplands in East Africa, four symbiotic acacia-ant species compete for possession of a single swollen thorn tree species, Acacia drepanolobium, and yet coexist at fine spatial scales. Three of the four ant species produce independent foundress queens that establish colonies claustrally within swollen thorns, most often on small saplings. We conducted surveys of such saplings at two sites in 2001 and 2004, and examined foundresses and incipient colonies within their swollen thorns to determine what factors influence their success. Competition among foundresses for nest initiation sites was intense, with an average of over one founding attempt per swollen thorn in all samples, and with living and dead queens significantly hyper-dispersed among available thorns. Combat with other foundresses was the most common cause of death among claustral queens, especially for Tetraponera penzigi. In interspecific battles for nest initiation sites, T. penzigi was dominant over Crematogaster nigriceps and C. mimosae, and C. nigriceps won over 80% of its contests with C. mimosae foundresses. For singleton foundresses, brood parasitism by the braconid wasp Trigastrotheca laikipiensis typically results in the death of the entire ant brood. Host queens defend parasite larvae, pupae and eclosed adults, apparently unable to distinguish the wasps from legitimate offspring. Rates of brood parasitism were as high as 15–20% for incipient colonies of both Crematogaster species, but were extremely low for T. nigriceps in all samples. Although T. penzigi and C. nigriceps foundresses are always solitary, approximately 18% of claustral C. mimosae colonies contain cooperating pleometrotic queens. For unparasitized, claustral C. mimosae colonies, brood production per queen did not differ between solitary and cooperating foundresses. However, the per-capita risks associated with parastitism were reduced for pleometrotic queens. Received 8 March 2005; revised 23 May 2005; accepted 3 June 2005.  相似文献   

9.
Eastern cottontail (Sylvilagus floridanus, fam. Leporidae), introduced into Piedmont (Italy) in the 1960s, was studied as carrier of dermatophyte fungi. Of 216 hair samples collected from animals culled between September 1999 and July 2000 in the Province of Alessandria (Piedmont, Italy) during a pest control project, 57 (26.4%) yielded dermatophyte colonies. As two different species of dermatophytes grew from two samples, a total of 59 fungal isolates (26.5%) were obtained. Six dermatophyte species both geophilic (M. gypseum, M. cookei, Trichophyton ajelloi, T. terrestre) and zoophilic (M. canis, T. mentagrophytes) were identified. No sex-related differences were found but season-related differences were observed. The highest prevalence of dermatophyte-positive samples was recorded in May–September, due to the geophilic fungi whose prevalence decreased during colder and increased during warmer months ( p < 0.001). The presence of zoophilic dermatophytes, T. mentagrophytes, commonly associated with rodents, small mammals and lagomorphs and M. canis, usually correlated with domestic environment, did not change the whole year round. As Eastern cottontail has been showed to be a carrier of dermatophytes transmissible to man (M. canis, T. mentagrophytes and M. gypseum), it may represent a source of infection for gamekeepers, hunters and veterinarians.  相似文献   

10.
The term cutworm covers a range of species with a similar life history that can be very damaging pests on a wide range of crops. Attacks by cutworms are often made up of more than one species; thus, the most cost effective microbial control agent needs to be pathogenic for multiple species within this complex. In this study we investigate the host range of Agrotis segetum NPV and A. segetum GV for other cutworm species and closely related Noctuinae. Eight species, A. segetum, Agrotis ipsilon, Agrotis exclamationis, Agrotis puta, Noctua comes, Peridroma saucia, Xestia sexstrigata, and Xestia xanthographa, were clearly susceptible to AgseNPV, which was confirmed by DNA analysis. Aglais urticae, Diarsia rubi, Noctua pronuba, and Xestia c-nigrum were not susceptible to AgseNPV at the doses used. Noctua fimbriata, Noctua janthina, and Ochroplura plecta gave ambivalent results: larvae died of NPV infection when they were challenged with AgseNPV, but these individuals only produced weak positives in a squash blot analysis and there was insufficient DNA for confirmation by restriction endonuclease profiling. These ambivalent results could suggest either a weak infection by AgseNPV or partial homology between their own virus and AgseNPV. The untreated control insects of several species died of NPV infection, which indicates that these field-collected insects were probably carrying a vertically transmitted NPV. Fewer species were tested with AgseGV and only N. pronuba and N. comes were susceptible. N. fimbriata and Helicoverpa armigera were not susceptible to AgseGV.  相似文献   

11.
Parish R  Antos JA 《Oecologia》2004,141(4):562-576
Old-growth forests are common in the snowy, montane environments of coastal western North America. To examine dynamics of a stand containing four canopy tree species (Abies amabilis, Chamaecyparis nootkatensis, Tsuga mertensiana and T. heterophylla), we used four stem-mapped, 50 m ×50 m plots. From measurements of annual rings, we obtained ages from basal discs of 1,336 live trees, developed master chronologies for each species, reconstructed early growth rates, and delineated periods of release. The stand was ancient; individuals of all four species exceeded 900 years in age, and the oldest tree exceeded 1,400 years. The four plots differed in the timing of events, and we found no evidence of major, stand-level disturbance. Instead the stand was structured by small-scale patch dynamics, resulting from events that affected one to several trees and initiated episodes of release and relatively rapid early growth. The species differed in age structure and dynamics. A. amabilis and T. heterophylla had a classical reverse-J age structure indicative of stable populations, whereas C. nootkatensis and T. mertensiana appeared to rely on local episodes of increased recruitment, which were often separated by centuries, and were probably related to multiple-tree gaps that occurred infrequently. However, such gaps could be considered normal in the long-term history of the stand, and thus these species with their long life spans can persist. Most individuals of all four species grew extremely slowly, with trees typically spending centuries in the understory before reaching the canopy, where they were able to persist for additional centuries. Thus, the key features of this forest are the very slow dynamics dominated by small-scale events, and the slow growth of stress-tolerant trees.  相似文献   

12.
银白色葡萄球菌(Staphylococcus argenteus)是金黄色葡萄球菌(S. aureus)的近缘新种,于2015年正式被鉴定、命名。在此之前,银白色葡萄球菌一直被认为是金黄色葡萄球菌种内的一个远源支系。该物种绝大多数菌株分离自人体,基因组上含有大量与金黄色葡萄球菌同源的毒力基因,可导致与金黄色葡萄球菌类似的临床感染和食物中毒症状。因为与人类健康相关,银白色葡萄球菌受到了越来越多的关注,目前已在20多个国家被报道。但是由于出现较晚,与金黄色葡萄球菌难以区分,银白色葡萄球菌的全球分布状况、原始生境和传播过程尚不清楚。本文从发现过程、分布、致病性和鉴定方法等方面综述了银白色葡萄球菌的最新研究进展。  相似文献   

13.
Polystichum, one of the largest genera of ferns, occurs worldwide with the greatest diversity in southwest China and adjacent regions. Although there have been studies of Chinese Polystichum on its traditional classification, geographic distributions, and even a few on its molecular systematics, its relationships to other species outside China remain little known. Here, we investigated the phylogeny and biogeography of the Polystichum species from China and Australasia. The evolutionary relationships among 42 Polystichum species found in China (29 taxa) and Australasia (13 taxa) were inferred from phylogenetic analyses of two chloroplast DNA sequence data sets: rps4-trnS and trnL-F intergenic spacers. The divergence time between Chinese and Australasian Polystichum was estimated. The results indicated that the Australasian species comprise a monophyletic group that is nested within the Chinese diversity, and that the New Zealand species are likewise a monophyletic group nested within the Australasian species. The divergence time estimates suggested that Chinese Polystichum migrated into Australasia from around 40 Ma ago, and from there to New Zealand from about 14 Ma. The diversification of the New Zealand Polystichum species began about 10 Ma. These results indicated that Polystichum probably originated in eastern Asia and migrated into Australasia: first into Australia and then into New Zealand.  相似文献   

14.
Phylogenetic relationships of 48 species of Caragana (Fabaceae: tribe Hedysareae) and one representative each of Astragalus, Calophaca, Halimodendron, and Hedysarum are estimated from DNA sequences of the rbcL gene, trnStrnG intron and spacer, and ITS region. At least one representative of all five sections and 12 series within Caragana are included. Analyses yielded strongly supported clades corresponding to sections Caragana, Bracteolatae, and Frutescentes. The species of section Jubatae are distributed among three strongly supported clades, i.e., one with the species of section Bracteolatae, another with two species of section Spinosae, and a third as sister to section Frutescentes. All but the last of these six clades are corroborated by at least one unambiguously traced morphological character. The placement of the other four species of section Spinosae are not well supported and lack unambiguous morphological synapomorphies, and the samples of Calophaca and Halimodendron nest within Caragana with weak support.  相似文献   

15.
The phylogenetic relationships within many clades of the Crassulaceae are still uncertain, therefore in this study attention was focused on the “Acre clade”, a group comprised of approximately 526 species in eight genera that include many Asian and Mediterranean species of Sedum and the majority of the American genera (Echeveria, Graptopetalum, Lenophyllum, Pachyphytum, Villadia, and Thompsonella). Parsimony and Bayesian analyses were conducted with 133 species based on nuclear (ETS, ITS) and chloroplast DNA regions (rpS16, matK). Our analyses retrieved four major clades within the Acre clade. Two of these were in a grade and corresponded to Asian species of Sedum, the rest corresponded to a European–Macaronesian group and to an American group. The American group included all taxa that were formerly placed in the Echeverioideae and the majority of the American Sedoideae. Our analyses support the monophyly of three genera – Lenophyllum, Thompsonella, and Pachyphytum; however, the relationships among Echeveria, Sedum and the various segregates of Sedum are largely unresolved. Our analyses represents the first broad phylogenetic framework for Acre clade, but further studies are necessary on the groups poorly represented here, such as the European and Asian species of Sedum and the Central and South American species of Echeveria.  相似文献   

16.
A molecular phylogeny of Hebeloma species from Europe   总被引:2,自引:1,他引:1  
In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.  相似文献   

17.
Truffle trouble: what happened to the Tuberales?   总被引:1,自引:1,他引:0  
An overview of truffles (now considered to belong in the Pezizales, but formerly treated in the Tuberales) is presented, including a discussion on morphological and biological traits characterizing this form group. Accepted genera are listed and discussed according to a system based on molecular results combined with morphological characters. Phylogenetic analyses of LSU rDNA sequences from 55 hypogeous and 139 epigeous taxa of Pezizales were performed to examine their relationships. Parsimony, ML, and Bayesian analyses of these sequences indicate that the truffles studied represent at least 15 independent lineages within the Pezizales. Sequences from hypogeous representatives referred to the following families and genera were analysed: DiscinaceaeMorchellaceae (Fischerula, Hydnotrya, Leucangium), Helvellaceae (Balsamia and Barssia), Pezizaceae (Amylascus, Cazia, Eremiomyces, Hydnotryopsis, Kaliharituber, Mattirolomyces, Pachyphloeus, Peziza, Ruhlandiella, Stephensia, Terfezia, and Tirmania), Pyronemataceae (Genea, Geopora, Paurocotylis, and Stephensia) and Tuberaceae (Choiromyces, Dingleya, Labyrinthomyces, Reddellomyces, and Tuber). The different types of hypogeous ascomata were found within most major evolutionary lines often nesting close to apothecial species. Although the Pezizaceae traditionally have been defined mainly on the presence of amyloid reactions of the ascus wall several truffles appear to have lost this character. The value of the number of nuclei in mature ascospores as a delimiting family character is evaluated and found to be more variable than generally assumed.  相似文献   

18.
The commercially available strains of Phytoseiulus persimilis Athias-Henriot, the biological control agent of Tetranychus urticae Koch, perform poorly in the Western Mediterranean, probably because they are not well adapted to local climatic conditions. For that reason, efforts are being focused on the development of a biological control programme using native phytoseiid mites. Four species of red spider mites can be found in vegetable crops in eastern Spain: T. urticae, Tetranychus turkestani Ugarov and Nikolski, Tetranychus ludeni Zacher and the recently introduced Tetranychus evansi Baker and Pritchard. To evaluate their potential role as biological control agents, the present study evaluates the life-history of local populations of Neoseiulus californicus (McGregor) and P. persimilis when fed on T. urticae, T. turkestani, T. evansi, and T. ludeni in the laboratory. Results indicate that N. californicus and P. persimilis are able to feed and complete their development on the four tested red spider mite species. The predators may exhibit a particularly high capacity for population increase when fed on T. urticae, T. turkestani, and T. ludeni, thus may be able to provide effective control of these species in the field. When fed T. evansi, however, predator performance was poor; significant increase in development and preoviposition times, and a reduction in oviposition period and fecundity were recorded. The resultant low capacity for population growth suggests poor ability of the two tested predators to suppress T. evansi populations on commercial crops. It is unlikely therefore that P. persimilis and N. californicus, now being widely used to control T. urticae in greenhouse crops in Central Europe, will be able to halt any spread of T. evansi to greenhouse crops in temperate areas.  相似文献   

19.
The ecological impact of introduced biological control agents on native species of arthropods is a matter of considerable debate. This study investigated the ability of the non-native predatory mite Neoseiulus californicus to feed on the native Typhlodromus pyri and vice versa, as both species now co-occur in UK orchards. Typhlodromips montdorensis is a candidate for introduction into the UK as a glasshouse biological control agent. The ability of T. montdorensis to feed on the widely used N. californicus was investigated to identify possible intraguild predation, which might influence the effectiveness of either or both species as predators of Tetranychus urticae. Both N. californicus and T. pyri consumed larval stages of each other, but in choice experiments both showed a preference for T. urticae. Both N. californicus and T. montdorensis also fed on each other, but whereas N. californicus again showed a preference for T. urticae, T. montdorensis fed equally on T. urticae and N. californicus. Interactions between N. californicus and T. pyri and N. californicus and T. montdorensis are discussed in relation to their effectiveness as biological control agents in the glasshouse and the natural control of spider mite in the field.  相似文献   

20.
A molecular method using the polymerase chain reaction (PCR) amplification of small subunit gene sequences (18S rDNA) and denaturing gradient gel electrophoresis (DGGE) was used to determine both the population complexity and species identification of organisms in harmful algal blooms. Eighteen laboratory cultures of dinoflagellates, including Akashiwo, Gymnodinium, Heterocapsa, Karenia, Karlodinium, Pfiesteria, and Pfiesteria-like species were analyzed using dinoflagellate-specific oligonucleotide primers and DGGE. The method is sensitive and able to determine the number of species in a sample, as well as the taxonomic identity of each species, and is particularly useful in detecting differences between species of the same genus, as well as differences between morphologically similar species. Using this method, each of eight Pfiesteria-like species was verified as being clonal isolates of Pfiesteria piscicida. The sensitivity of dinoflagellate DGGE is approximately 1000 cells/ml, which is 100-fold less sensitive than real-time PCR. However, the advantage of DGGE lies in its ability to analyze dinoflagellate community structure without needing to know what is there, while real-time PCR provides much higher sensitivity and detection levels, if probes exist for the species of interest, attributes that complement DGGE analysis. In a blinded test, dinoflagellate DGGE was used to analyze two environmental fish kill samples whose species composition had been previously determined by other analyses. DGGE correctly identified the dominant species in these samples as Karlodinium micrum and Heterocapsa rotundata, proving the efficacy of this method on environmental samples. Toxin analysis of a clonal isolate obtained from the fish kill samples confirmed the presence of KmTx2, corroborating the earlier genetic identification of toxic K. micrum in the fish kill water sample.  相似文献   

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