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1.
The phylogeny and taxonomy of Phytophthora cryptogea and Phytophthora drechsleri has long been a matter of controversy. To re-evaluate this, a worldwide collection of 117 isolates assigned to either P. cryptogea, P. drechsleri or their sister taxon, Phytophthora erythroseptica were assessed for morphological, physiological (pathological, cultural, temperature relations, mating) and molecular traits. Multiple gene phylogenetic analysis was performed on DNA sequences of nuclear (internal transcribed spacers (ITS), ß-tubulin, translation elongation factor 1α, elicitin) and mitochondrial (cytochrome c oxidase subunit I) genes. Congruence was observed between the different phylogenetic data sets and established that P. drechsleri and P. cryptogea are distinct species. Isolates of P. drechsleri form a monophyletic grouping with low levels of intraspecific diversity whereas P. cryptogea is more variable. Three distinct phylogenetic groups were noted within P. cryptogea with an intermediate group providing strong evidence for introgression of previously isolated lineages. This evidence suggests that P. cryptogea is an operational taxonomic unit and should remain a single species. Of all the morphological and physiological traits only growth rate at higher temperatures reliably discriminated isolates of P. drechsleri and P. cryptogea. As a homothallic taxon, P. erythroseptica, considered the cause of potato pink rot, is clearly different in mating behaviour from the other two species. Pathogenicity, however, was not a reliable characteristic as all isolates of the three species formed pink rot in potato tubers. The phylogenetic evidence suggests P. erythroseptica has evolved from P. cryptogea more recently than the split from the most recent common ancestor of all three species. However, more data and more isolates of authentic P. erythroseptica are needed to fully evaluate the taxonomic position of this species.  相似文献   

2.
Fatty acid methyl ester (FAME) profiles and amplified fragment length polymorphisms (AFLPs) were evaluated as tools for identifying species of Phytophthora. Five isolates of each of Phytophthora cactorum, Phytophthora citrophthora, Phytophthora cinnamomi, Phytophthora nicotianae and Phytophthora cryptogea were subjected to both analyses to examine variation among and within species. In FAME analysis, isolates of P. cactorum, P. cinnamomi and P.nicotianae were clustered by species, but isolates of P. citrophthora and P.cryptogea were divided into multiple clusters based on greater variations within these two species. The AFLP analysis differentiated all five species of Phytophthora. The five isolates of each species were grouped in a separate terminal cluster, but diversity within a species cluster varied considerably with variation greater in P. cryptogea and P. citrophthora. Comparing the dendrograms based on FAME and AFLP analyses, the overall patterns of both were similar. The P. cactorum cluster was distinct from clusters of the other four species, which formed one large cluster. The higher values of percentages of polymorphic loci and gene diversity in AFLP analysis substantiated diversity observed among isolates of P. citrophthora and P. cryptogea in FAME and AFLP dendrograms. Both FAME and AFLP appear to be useful tools for identifying species of Phytophthora, but only AFLP analysis has potential to study genetic and phylogenetic relationships within and among species in this genus.  相似文献   

3.
Vine decline of kiwifruit was observed in an orchard in Bart?n province of Turkey. Affected vines exhibited poor terminal growth, leaf discoloration and various degrees of dieback, including complete vine death. Symptoms were observed in the field on roots, crowns and stems. Two Phytophthora species were isolated from decayed cortical roots and lower stems of kiwifruits. They were identified as Phytophthora cryptogea and Phytophthora megasperma by their morphological characteristics and the analysis of sequences of the internal transcribed spacer (ITS) region of the rDNA. Pathogenicity of the isolates was tested by stem inoculation on kiwifruit seedlings. After 4 weeks, cankers developed in the plants inoculated with P. cryptogea, while no cankers formed in those inoculated with P. megasperma and in control plants. This is the first report of P. cryptogea causing root and stem rot of kiwifruit in Turkey.  相似文献   

4.
The phylogenetic utility of chloroplast (atpB-rbcL, petD, rps16, trnL-F) and nuclear (ETS, ITS) DNA regions was investigated for the tribe Spermacoceae of the coffee family (Rubiaceae). ITS was, despite often raised cautions of its utility at higher taxonomic levels, shown to provide the highest number of parsimony informative characters, in partitioned Bayesian analyses it yielded the fewest trees in the 95% credible set, it resolved the highest proportion of well resolved clades, and was the most accurate region as measured by the partition metric and the proportion of correctly resolved clades (well supported clades retrieved from a combined analysis regarded as “true”). For Hedyotis, the nuclear 5S-NTS was shown to be potentially as useful as ITS, despite its shorter sequence length. The chloroplast region being the most phylogenetically informative was the petD group II intron.We also present a phylogeny of Spermacoceae based on a Bayesian analysis of the four chloroplast regions, ITS, and ETS combined. Spermacoceae are shown to be monophyletic. Clades supported by high posterior probabilities are discussed, especially in respect to the current generic classification. Notably, Oldenlandia is polyphyletic, the two subgenera of Kohautia are not sister taxa, and Hedyotis should be treated in a narrow sense to include only Asian species.  相似文献   

5.
Heterogeneity of the rDNA ITS region in Pythium helicoides and the phylogenetic relationship between P. helicoides and closely related species were investigated. In PCR-RFLP analysis of the rDNA ITS region of six P. helicoides isolates investigated, including the type culture, intraspecific variation was found at the HhaI site. The total length of fragments was longer than before cutting, indicating sequence heterogeneity within isolates. Digestion of the cloned rDNA ITS region derived from seven isolates with HhaI revealed polymorphisms among and within single zoospore isolates, and variability of the region was also present among the clones derived from the same isolate. To test whether the rDNA ITS region of closely related species and other regions in the genome of P. helicoides are also variable, the rDNA ITS region of P. ultimum and the cytochrome oxydase II (cox II) gene encoded in mitochondria were sequenced. P. ultimum had little variation in the rDNA ITS region. The cox II gene sequences of both species revealed only a low intraspecific variability and no intra-isolate variation. In the phylogenic tree based on the rDNA ITS sequences, all clones of P. helicoides formed one large clade that was distinct from the clades comprising morphologically similar species, such as P. oedochilum and P. ostracodes, and was closely related to P. chamaehyphon rather than the other species.  相似文献   

6.
Ergosterol was isolated from the plant pathogenic pseudofungus Phytophthora drechslerigrown on clarified V8 booth (CV8-B). Its structure was confirmed by comparison to an authentic sample. The species was identified by morphological analysis and molecular characterization by PCR: ITS (Internal transcribed spaces). This is the first report of this sterol in Phytophthora.This result is unusual becausePhytophthora fungi were previously thought to be unable to synthesize sterols and the Oomycetes in general do not produce ergosterol.  相似文献   

7.
Phylogenetic relationships within the complex genus Lupinus are estimated from internal transcribed spacer (ITS) sequences of the nuclear ribosomal DNA repeat. The molecular data supports Lupinus as a distinct monophyletic group within the tribe Genisteae. Different geographical lineages are revealed within Lupinus, which are each restricted to either the Old or the New World. In the New World, the ITS data support an eastern-western geographic disjunction of the lupines and the recognition of some well-supported clades. In the Old World, almost all the previously recognized taxa are taxonomically well differentiated. The homogeneous African rough-seeded lupines, Scabrispermae, are strongly supported as a monophyletic group, which is distinct from the diverse and heterogeneous circum-Mediterranean smooth-seeded ones. The latter appear to have evolved as two lineages, in which are revealed some intersectional relationships. Also ITS data allow the assessment of the phylogenetic position of the newly discovered species, L. anatolicus (in the Old World) and L. jaimehintoniana (the Mexican tree lupin). The ITS phylogeny suggests a rapid initial radiation of the lupines subsequent to their divergence from a common ancestor. Moreover, the results indicate that the annual and perennial habits have evolved many times in Lupinus and suggest a role for generation time in affecting the evolutionary history of lupines. Data on adaptive processes and character evolution are re-examined and discussed in the light of the ITS phylogeny.These studies were supported by the research unit UMR-CNRS 6553 Ecobio – University of Rennes (France), and by the NSERC of Canada (grant to R.J. Bayer, at the University of Alberta). They are greatfully acknowledged. All the persons that have contributed in different ways to this work on Lupinus, summarized in this presentation, are greatly thanked. Particularly, we would like to mention Malika Aïnouche, Roland Greinwald, André Huon, W.K. Swiecicki, Billie L. Turner and Ludger Witte for their contributions.  相似文献   

8.
Cypripedioideae (Orchidaceae) have been the subject of numerous taxonomic treatments with conflicting interpretations of relationships among the five genera and the 150–170 species. We have produced nuclear ribosomal ITS nucleotide sequences for nearly 100 slipper orchid species and used parsimony analysis to investigate their relationships. Our results demonstrate that each genus, as currently circumscribed, is monophyletic (Mexipedium andSelenipedium being represented by a single taxon). LikerbcL data, ITS sequences placeMexipedium sister toPhragmipedium. Relationships at the sectional level inPaphiopedilum are largely as described byCribb. However, the division ofPaphiopedilum into subgg.Brachypetalum andPaphiopedilum is not supported; subg.Brachypetalum is paraphyletic to subg.Paphiopedilum. Phragmipedium species are divided into the same three major clades as in the taxonomic scheme ofMcCook. The plicate-leaved genera,Cypripedium andSelenipedium, are successive sister groups to the rest of the subfamily, confirming generally held opinions that they display plesiomorphic characters compared to the conduplicate-leaved genera. A survey of karyotypes in the context of the ITS tree reveals a general trend toward increased chromosome number, probably brought about by centric fission. These data also accord with a previously suggested biogeographic hypothesis of a widespread Northern Hemisphere distribution, followed by range fragmentation due to Miocene cooling.  相似文献   

9.
Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.  相似文献   

10.
Biological control of fungi causing root rot on sugar beet by native Streptomyces isolates (C and S2) was evaluated in this study. The dry weight and colony forming unit (CFU) of S2 and C increased when 300 mM NaCl was added to medium. The in vitro antagonism assays showed that both isolates had inhibitory effect against Rhizoctonia solani AG-2, Fusarium solani and Phytophthora drechsleri. In dual culture, Streptomyces isolate C inhibited mycelial growth of R. solani, F. solani and P. drechsleri 45%, 53% and 26%, respectively. NaCl treatment of medium increased biocontrol activity of soluble and volatile compounds of isolate C and S2. After salt treatment, growth inhibition of R. solani, F. solani and P. drechsleri by isolate C increased up to 59%, 70% and 79%, respectively. To elucidate the mode of antagonism, protease, chitinase, beta glucanase, cellulase, lipase and α-amylase activity and siderophore and salicylic acid (SA) production were evaluated. Both isolates showed protease, chitinase and α-amylase activity. Also, biosynthesis of siderophore was detectable for both isolates. Production of siderophore and activity of protease and α-amylase increased after adding salt for both isolates. In contrast, chitinase activity decreased significantly. Production of SA, beta glucanase and lipase by isolate S2 and biosynthesis of cellulase by isolate C were observed in presence and absence of NaCl. Soil treatment with Streptomyces isolate C inhibited root rot of sugar beet caused by P. drechsleri, R. solani and F. solani. Results of this study showed that these two Streptomyces isolates had potential to be utilized as biocontrol agent against fungal diseases especially in saline soils.  相似文献   

11.
Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered as the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. In the endemic regions of the North of Iran, Fasciola hepatica and Fasciola gigantica have been previously characterized on the basis of morphometric differences, but the use of molecular markers is necessary to distinguish exactly between species and intermediate forms. Samples from buffaloes and goats from different localities of northern Iran were identified morphologically and then genetically characterized by sequences of the first (ITS-1) and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the northern Iranian samples with sequences of Fasciola spp. from GenBank showed that the examined specimens had sequences identical to those of the most frequent haplotypes of F. hepatica (n = 25, 48.1%) and F. gigantica (n = 20, 38.45%), which differed from each other in different variable nucleotide positions of ITS region sequences, and their intermediate forms (n = 7, 13.45%), which had nucleotides overlapped between the two Fasciola species in all the positions. The ITS sequences from populations of Fasciola isolates in buffaloes and goats had experienced introgression/hybridization as previously reported in isolates from other ruminants and humans. Based on ITS-1 and ITS-2 sequences, flukes are scattered in pure F. hepatica, F. gigantica and intermediate Fasciola clades, revealing that multiple genotypes of Fasciola are able to infect goats and buffaloes in North of Iran. Furthermore, the phylogenetic trees based upon the ITS-1 and ITS-2 sequences showed a close relationship of the Iranian samples with isolates of F. hepatica and F. gigantica from different localities of Africa and Asia. In the present study, the intergenic transcribed spacers ITS-1 and ITS-2 showed to be reliable approaches for the genetic differentiation of Fasciola spp., providing bases for further studies on F. hepatica, F. gigantica and their intermediate forms in the endemic areas in Asia.  相似文献   

12.

Candida auris, a multidrug-resistant nosocomial pathogen, has emerged globally with high morbidity and mortality among immunocompromised individuals and COVID19 hospitalized patients. Five major clades of C. auris have been previously described. The fifth clade is exclusively found in Iran where C. auris isolates are genetically distinct from other clades by?>?200,000 single-nucleotide polymorphisms. The origin of C. auris remains unclear, and limited clinical data are available at present regarding clade V infection or colonization. Herein, another case of otomycosis in Iran caused by an isolate of C. auris belonging to the fifth clade is reported. Genotyping revealed that the obtained C. auris isolate from Isfahan clustered with earlier clade V isolates from Babol, cities around 600 km separated, which indicates that C. auris clade V is established in Iran. C. auris is thought to exist more commonly in Iran, given that limited diagnostic capacity in the country has probably curbed the identification of more C. auris cases. Therefore, surveillance of the environment, patients and healthcare facilities in different geographical regions in Iran is urgently required.

  相似文献   

13.
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   

14.
Exploratory activities were done in Syria, Turkey, Iran, Uzbekistan, Kazakhstan, The Kyrghyz Republic, and Russia to locate entomopathogenic fungi of Eurygaster integriceps. Isolates from the entomopathogenic genera Beauveria, Paecilomyces, and Verticillium were collected. Beauveria bassiana was the most commonly recovered species. Thirty-one isolates of the 221 recovered were examined at 20, 25, 30, and 35 °C for 20 days for growth and sporulation. Growth and sporulation were generally highest at 25 °C. None of the isolates grew at 35 °C, and at 30 °C growth was retarded with no conidia being produced. Single- and multiple-concentration bioassays were conducted on greenhouse-grown wheat plants and in pine litter to evaluate virulence of fungi from several sources to E. integriceps. When tested at a single concentration, mortality after 15 days ranged from 66 to >95% in the litter assays and 50 to 91% in the plant assays. There was a distinct concentration response for most of the isolates tested in the multiple-concentration assay, particularly in the in-litter environment. In litter, mortality tended to develop earlier than in on-plant assays. Several isolates of B. bassiana and one Metarhizium anisopliae displayed consistently high virulence against E. integriceps and were more virulent than two commercial strains. Our results demonstrate the potential of entomopathogenic fungi for management of E. integriceps in overwintering sites and in wheat fields.  相似文献   

15.
Since the summer 2017, severe decline symptoms have been observed on 10- to 25-year-old avocado trees in almost all commercial orchards planted in the Mediterranean coastal region of Turkey. Young, newly planted trees in infected orchards were also affected by the disease. Affected trees showed wilting, leaf discoloration, defoliation and severe dieback. Some trees were completely desiccated. Although fine roots of symptomatic trees usually were decayed, reddish brown cankers also occurred on taproots and lateral roots of heavily infected trees. The pathogens were isolated from necrotic root and soil samples of symptomatic trees, using selective medium and soil baiting, and were identified based on morphological features and DNA sequences of the internal transcribed spacer (ITS) region. One isolate each of Phytophthora cryptogea and P. palmivora was identified, while all other isolates were P. cinnamomi. In addition, a subcortical fan-shaped mycelium, characteristic of Armillaria spp., was observed in the stem base of a symptomatic tree and identified as Armillaria gallica by DNA sequences of the internal transcribed spacer (ITS) and the translational elongation factor 1-α (EF 1-α) gene regions. Pathogenicity of Phytophthora isolates was tested by stem inoculation on one-year-old avocado seedlings. Two months after inoculation, canker lesions developed on stems of seedlings inoculated by any of the three Phytophthora spp. In contrast, collenchyma callus formed over the wound points on control plants over the same time period. This is the first report of P. cinnamomi, P. cryptogea, P. palmivora and A. gallica causing root rot of avocado trees in Turkey. In addition, P. cryptogea and A. gallica are reported for the first time associated with disease on this host. Due to the severe symptoms and widespread occurrence, P. cinnamomi should be considered a potential threat to avocado cultivation and natural ecosystems of this region of Turkey.  相似文献   

16.
Phytophthora austrocedrae is a new species isolated from necrotic lesions of stem and roots of Austrocedrus chilensis. It is a homothallic species characterized by semipapillate sporangia, oogonia with amphigynous antheridia, and very slow growth (1–2 mm d−1 on V-8 agar at 17.5 °C optimum temperature). Phylogenetic analysis of ITS rDNA sequence indicates that its closest relative is Phytophthora syringae, another species frequently isolated from soil and streams in A. chilensis forests.  相似文献   

17.
A distinctive new penicillium species, Penicillium macrosclerotiorum, isolated from soil in south China is reported. Morphologically, it resembles P. thomii, but is distinguished from the latter by its large, white to ivory coloured sclerotia, smooth-walled stipes, and globose, smooth-walled conidia. Although its rDNA ITS1–5.8S–ITS2 sequence is identical with that of P. thomii, the partial calmodulin gene sequence data show that it is a unique taxon and has no closely related relatives in penicillia.  相似文献   

18.
Parsimony analyses based on DNA sequence data of the plastid group II intron rps16 and the internal transcribed spacer (ITS) were performed in order to examine the relationship of the pantropical subfamily Alpinioideae in Zingiberaceae (Zingiberales). Special emphasis was given to the large genus Etlingera placed in the tribe Alpinieae. A total of 50 taxa were included in the analysis. The strict consensus tree obtained by combining all data (280 parsimony informative characters of ITS, rps16, and coded indels) is well resolved with strongly supported clades. The subfamily Alpinioideae (excluding Pommereschea and Rhynchanthus) is strongly supported as monophyletic. The basal part of the tree is unresolved but a clade containing the derived genera of Alpinieae (Geocharis, Amomum, Hornstedtia, and Etlingera) is strongly supported. The establishment of Etlingera as the inclusive name for Achasma, Geanthus, and Nicolaia is also strongly supported: Etlingera is monophyletic with Hornstedtia as sister group.  相似文献   

19.
Phylogeny of the Taxaceae genera and the monotypic family Cephalotaxaceae has been extraordinarily controversial. In this paper chloroplast matK genes and nuclear ITS sequences were determined for all six genera of the two families and representatives of other conifer families. Analysis using either the nonsynonymous sites or the deduced amino acid sequences of matK genes strongly indicates that taxad genera and Cephalotaxaceae are monophyletic, with the Taxodiaceae/Cupressaceae clade as their sister group. Cephalotaxus is basal to the taxad genera, among which two clades, Torreya/Amentotaxus and Taxus/Pseudotaxus/Austrotaxus, are resolved. They correspond to Janchen's two tribes, Torreyeae and Taxeae. In Taxeae, Austrotaxus is the first to branch off. Analyses of the nuclear ITS sequence data corroborated the topology of the matK gene tree. These results refute the views that Cephalotaxaceae has no alliance with Taxaceae and that Austrotaxus and Amentotaxus should be excluded from the Taxaceae. We estimated the divergence time between the Taxodiaceae/Cupressaceae and the Cephalotaxaceae/Taxaceae clades to be 192–230 Myr ago and the divergence time between taxads and Cephalotaxus to be 149–179 Myr ago. Soon after the latter divergence event, within 6–8 Myr, the two taxad tribes originated. In conclusion, our data do not support Florin's claim that taxads could be traced to Devonian psilophytes (359–395 Myr ago).  相似文献   

20.
During a survey of bryophilous fungi from boreal and montane habitats in central Alberta, a hitherto undescribed species of Cladophialophora was recovered from Polytrichum juniperinum, Aulacomnium palustre, and Sphagnum fuscum. On potato dextrose agar (PDA) colonies grew slowly, attaining a diameter of 25 mm after 30 d, were dark grey, velvety, radially sulcate, and convolute and cracked at the centre. Micronematous conidiophores gave rise to branched chains of small (1–2 × 8–22 μm), cylindrical to fusiform conidia with truncate, swollen scars at each end. Phylogenies built on the ITS and ribosomal SSU regions indicate the isolates form a monophyletic clade within the family Herpotrichiellaceae (Chaetothyriales) that is composed of two geographically based groups, each with 99 % within-group sequence similarity and 97–98 % between-group sequence similarity. A teleomorph has not been found but would likely be similar to species of Capronia. In vitro inoculation of the isolates onto axenically grown P. juniperinum produced no discernible host symptoms, and host penetration could not be detected using light microscopy. The production of polyphenol oxidases by the fungus and the role of other Cladophialophora species as latent endophytes and saprobes suggest that a potential role for the fungus is the degradation of the polyphenol-rich cell walls of mosses. A dichotomous key to species of the genus Cladophialophora is provided.  相似文献   

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