ITS rDNA Sequence Analysis Research Articles

Genetic variability and mycohost association of Ampelomyces quisqualis isolates inferred from phylogenetic analyses of ITS rDNA and actin gene sequences

Ampelomyces quisqualis complex is well known as the most common and widespread hyperparasite of the family Erysiphaceae, the cause of powdery mildew diseases. As commercial biopesticide products it is widely used to control the disease in field and plastic houses. Although genetic diversity within Ampelomyces isolates has been previously recognized, a single name A. quisqualis is still applied to all pycnidial intracellular hyperparasites of powdery mildew fungi. In this study, the phylogenetic relationships among Ampelomyces isolates originating from various powdery mildew fungi in Korea were inferred from Bayesian and maximum parsimony analyses of the sequences of ITS rDNA region and actin gene. In the phylogenetic trees, the Ampelomyces isolates could be divided into four distinct groups with high sequence divergences in both regions. The largest group, Clade 1, mostly accommodated Ampelomyces isolates originating from the mycohost Podosphaera spp. (sect. Sphaerotheca). Clade 2 comprised isolates from several genera of powdery mildews, Golovinomyces, Erysiphe (sect. Erysiphe), Arthrocladiella, and Phyllactinia, and was further divided into two subclades. An isolate obtained from Podosphaera (sect. Sphaerotheca) pannosa was clustered into Clade 3, with those from powdery mildews infecting rosaceous hosts. The mycohosts of Ampelomyces isolates in Clade 4 mostly consisted of species of Erysiphe (sect. Erysiphe, sect. Microsphaera, and sect. Uncinula). The present phylogenetic study demonstrates that Ampelomyces hyperparasite is indeed an assemblage of several distinct lineages rather than a sole species. Although the correlation between Ampelomyces isolates and their mycohosts is not obviously clear, the isolates show not only some degree of host specialization but also adaptation to their mycohosts during the evolution of the hyperparasite.

Morphological and molecular characterization of Mariannaea aquaticola sp. nov. collected from freshwater habitats

Mariannaea aquaticola sp. nov. is described, illustrated, and compared with closely related taxa. Phylogenetic analysis of rDNA ITS and 28S sequences show that Mariannaea aquaticola has affinity with Nectriaceae, which is in agreement with other Mariannaea species. Other morphologically similar genera such as Verticillium and Clonostachys are shown to be phylogenetically distant to Mariannaea. The generic concept of Mariannaea is discussed, and the affinity to Nectriaceous teleomorphs is suggested as additional generic character. A key to Mariannaea species is provided.

Ampelomyces의 생리적 특성 및 길항능력

2005년 6월부터 2008년 5월까지 전북 장수, 전주 및 전남 장성 등에서 흰가루병에 걸린 44종의 기주식물을 채집하였으며, 12종의 식물에서 Ampelomyces의 중복기생이 확인되었다. Ampelomyces의 병자각의 형태는 대부분이 원형 또는 타원형이었으며, 같은 기주식물에서도 그 크기가 다양했고, 병자각의 색은 옅은 갈색에서 진한 갈색이었다. 봉선화, 고들빼기, 쥬키니호박, 삼잎국화 로부터 Ampelomyces 균을 분리하였고, 이 중 실험에 적합한 Ampelomyces 균주 12개를 최종 선발하였다. 선발된 12균주의 배양적 특성 및 영양요구를 조사한 결과 Malt extract agar에서 가장 생육이 좋았다. 삼투압이 Ampelomyces의 포자발아에 미치는 영향에 대해 조사한 결과 Czapek dox agar에 질소원인 NaCl 0.15M을 첨가한 배지에서 포자발아율이 가장 높았다. Ampelomyces 분리 균의 길항 효과를 실험한 결과 다른 식물 병원균에 대한 항균효과가 있었다. 분리한 균주는 식물체에 이상이 생기거나 병이 발생하지 않아서 Ampelomyces는 식물에 병원성을 가지고 있지 않다는 사실을 알 수 있었다. 본 실험에 주로 사용된 균주 BSLAH16의 rDNA ITS 영역에 대한 염기서열을 분석한 결과 A. quisqualis 또는 Ampelomyces sp.로 동정 되었다. During the period of June, 2005 to May, 2008, 44 host plants infected with powdery mildew were collected in the Jeon-ju and Jang-su districts of Jeonbuk province and in the Jang-sung district of Jeonnam province. The hyperparasites, Ampelomyces were confirmed in 12 plant species. Most of the pycnidium shapes of Ampelomyces were circular or oval shaped, and the sizes were different even within the same host plant, and also the color of pycnidium was ranged from light brown to dark brown. Ampelomyces species were isolated from 4 hosts including Impatiens balsamina L., Cucurbita pepo, Rudbeckia laciniata var. elatier and Youngia sonchifolia, and thus the most appropriate 12 Ampelomyces strains for the current experiment were selected. When analyzing the selected 12 strains' incubational and nutritional characteristics, the malt extract agar was the most appropriate media. When investigating the effect of osmotic pressure on the spore germination, 0.15M NaCl concentration was the optimum germination concentration. When the isolated Ampelomyces sp. was tested in-vitro, it was found to be effective to control in other plant pathogens, isolated Ampelomyces showed no pathogenicity to the plant. strains isolated . studied on rDNA ITS sequence analysis. The rDNA ITS sequence data of Ampelomyces sp. isolate BSLAH16 from Impatiens balsamina L. were analyzed and identified.

Triterpene chemosyndromes and subtle morphological characters characterise lineages in the Physcia aipolia group in Australia (Ascomycota)

Species delimitation in lichens of the Physcia aipolia group in Australia has been studied based on thalline morphology (lobe width, upper surface pruinosity) and medullary triterpene chemistry as main character complexes. Previous treatments have utilised the presence or absence of atranorin and zeorin in the medulla as useful discriminators, but have neglected utilising the diversity of medullary triterpenes for taxonomic purposes. We have now tested the phylogenetic patterns of distribution of subtle morphological characters and terpenoid chemistry by means of molecular phylogenetic analysis of nuclear ITS and mitochondrial SSU rDNA sequences. Our analysis supports triterpene chemosyndromes and subtle morphological characters for the distinction of distinct lineages. Three new species are described for Australia, P. austrostellaris Elix, P. littoralis Elix and P. tropica Elix. In addition, the detailed chemical variation of species within the group is documented and three major chemosyndromes of triterpenes have been identified.

Genetic characterization of microbial communities living at the surface of building stones

The aim of the present study was to reveal the microbial genetic diversity of epilithic biofilms using a DNA-based procedure. A DNA extraction protocol was first selected to obtain PCR-amplifiable metagenomic DNA from a limestone biofilm. Extracted DNA was used to amplify either 16S rRNA genes or ITS regions from prokaryotic and eukaryotic genomes, respectively. Amplified DNAs were subsequently cloned, amplified by colony PCR and screened by restriction analysis [restriction analyses of amplified ribosomal DNA (ARDRA)] for DNA sequencing. Phylogenetic analysis using 16S rDNA sequences showed that predominating bacteria were Alphaproteobacteria belonging to the genera Sphingomonas, Erythrobacter, Porphyrobacter, Rhodopila and Jannashia; Cyanobacteria and Actinobacteria were also identified. Analysis of ITS rDNA sequences revealed the presence of algae of the Chlorophyceae family and fungi related either to Rhinocladiella or to a melanized ascomycete. Statistical analysis showed that the specific richness evidenced was representative of the original sampled biofilm. The molecular methodology developed here constitutes a valuable tool to investigate the genetic diversity of microbial biofilms from building stone. The easy-to-run molecular method described here has practical importance to establish microbiological diagnosis and to define strategies for protection and restoration of stone surfaces.

DIVERSITY AND ABUNDANCE OF POTENTIALLY TOXIC PSEUDO-NITZSCHIA PERAGALLO IN AVEIRO COASTAL LAGOON, PORTUGAL AND DESCRIPTION OF A NEW VARIETY, P. PUNGENS VAR. AVEIRENSIS VAR. NOV.

The syndrome Amnesic Shellfish Poisoning (ASP) results from ingesting sea food contaminated by a neurotoxin, domoic acid. Diatoms of the genera Pseudo-nitzschia and Nitzschia are responsible for the production of this toxin. A total of eleven species of Pseudo-nitzschia were identified during two plankton surveys at the entrance and in the southern channels of Ria de Aveiro, the largest lagoon on the west coast of Portugal. During the first survey, conducted from February to October 2000, the following species were identified: P. australis, P. cuspidata, P. delicatissima, P. dolorosa, P. fraudulenta, P. pseudodelicatissima, P. subpacifica and a new variety of P. pungens. The second survey took place from September 2003 to April 2004, except for a break between December 2003-January 2004, along with one complementary sample taken in October 2004; it revealed three additional species, P. americana, P. calliantha and P. multistriata. In contrast, P. cuspidata, P. dolorosa and P. subpacifica were not found during the second survey. Five species: P. subpacifica, P. americana, P. calliantha, P. multistriata and P. cuspidata were reported for the first time in Portuguese waters. Overall, P. australis, P. pseudodelicatissima and a new variety of P. pungens were the most common species, the latter being present in all samples except October 2000. The highest concentrations of Pseudo-nitzschia cells registered were 90, 000 cells L–1 in August 2000 and 106, 000 cells L−1 in March 2004, with P. australis accounting for 65–75% of the cells. Cell concentrations were highest near the entrance of the lagoon and decreased along with salinity in the channels. Cultures of P. australis, P. americana, P. fraudulenta, P. multistriata and a new variety of P. pungens were established and tested for the production of domoic acid, but the results were negative. Morphological differences were found between our strains of P. pungens and two other previously described varieties of P. pungens regarding valve width, densities of striae, fibulae, poroids and band striae as well as differences in the morphology of the band striae. These differences were supported by phylogenetic analyses of ITS rDNA sequences, existence of a compensatory base change and mating studies indicate the presence of a separate taxon, which was described as a new variety, P. pungens var. aveirensis var. nov.

Mycorrhizal synthesis of Tuber indicum with two indigenous hosts, Castanea mollissima and Pinus armandii

Tuber indicum is one of the most renowned commercialized fungi in China. Mycorrhizal investigations, however, have been carried out mainly with exotic trees. Up to now there is no detailed description of morphology of the mycorrhizae formed with the indigenous hosts of T. indicum. Containerized seedlings of two indigenous hosts of the fungus in southwestern China, Pinus armandii and Castanea mollissima, were inoculated with aqueous spore suspension of T. indicum in two kinds of substrates. Mycorrhizae began to form 4 months after inoculation and were harvested at 9 months. The contributing fungus of the mycorrhizae was confirmed to be T. indicum by morphological and ITS-rDNA sequence analyses. The morphology of emanating hyphae and epidermoid-like mantle appearance was similar to the mycorrhizae obtained with some European trees. The high morphological variation and the similarity to that of Tuber melanosporum makes it difficult to distinguish the mycorrhizae of the two species by morphology alone. The synthesis of mycorrhizae of T. indicum with its indigenous hosts will be of great significance for planned cultivation of the Asian black truffles.

Fungal endophytes fromAcer ginnalaMaxim: isolation, identification and their yield of gallic acid

The aim of the study was to isolate the endophytic fungi from Acer ginnala and screen isolates rich in gallic acid. After epiphytic sterilization, 145 fungal endophytes were isolated from the stem, annual twig and seed of Acer ginnala. The endophytes were grouped into ten different taxa, Phomopsis sp., Neurospora sp., Phoma sp., Epicoccum sp., Penicillium sp., Alternaria sp., Fusarium sp., Trichoderma sp., Cladosporium sp. and a species of Pleosporales Incertae Sedis, by their morphological traits and ITS-rDNA sequence analysis. The content and yield of gallic acid of 141 isolates were determined by HPLC. On average, the species of Pleosporales Incertae Sedis had the highest content and yield of gallic acid (13.28 mg g(-1) DW; 119.62 mg l(-1)), while Alternaria sp. had the lowest. Of 141 fungal endophytes from A. ginnala, Phomopsis sp. isolate SX10 showed both the highest content and the highest yield of gallic acid (29.25 mg g(-1) DW; 200.47 mg l(-1)). Endophytic fungi isolated from A. ginnala may be used as potential producers of gallic acid and other compounds with biological activities, or functioned as elicitors to produce natural compounds.

Phylogenetic relationships of Puccinia horiana and other rust pathogens of Chrysanthemum × morifolium based on rDNA ITS sequence analysis

Isolates of the most important Puccinia species that have been reported on Chrysanthemum × morifolium were collected and the sequences of their ribosomal DNA internal transcribed spacers ITS1 and ITS2 were determined and used as phylogenetic markers. The focus of this study was on Puccinia horiana, due to its quarantine status and its impact in commercial chrysanthemum production. Three technical adjustments were needed to reliably obtain the nucleotide sequences starting from fresh or dried samples. The complete rDNA ITS nucleotide sequences of P. horiana, Puccinia chrysanthemi, and Puccinia tanaceti isolates of varying age and geographic origin were determined. We also identified an as yet undescribed Puccinia species on six old herbarium samples from chrysanthemum. This new species is morphologically similar to P. chrysanthemi and near identical to recent rust samples from Artemisia tridentata. P. tanaceti could not be confirmed as a pathogen of chrysanthemum. Different rDNA ITS sequences were present in P. horiana, with intra-isolate and inter-isolate variability in the length of three nucleotide repeat regions in the different rDNA tandem copies. We also identified three ITS types within P. horiana, with the rarer types displaying up to 67 bp nucleotide sequence differences. These rarer ITS types were detected at low copy number in all isolates. In general, very little rDNA ITS sequence variation was observed between P. horiana isolates from 1903 and 2003, and among isolates from different continents. Phylogenetic analyses using distance, Maximum Likelihood and Bayesian methods confirmed P. horiana, P. chrysanthemi, and the new Puccinia sp. as well-resolved groups, with P. horiana clustering in the clade where the economically important rust species of the Poaceae are located, and P. chrysanthemi and the new Puccinia sp. clustering in the clade where the majority of the rust fungi with hosts in the Asteraceae is located.

Phylogeny of Broad-leaved and Fine-leaved Festuca Lineages (Poaceae) based on Nuclear ITS Sequences

Abstract This work presents a reconstruction of the phylogenetic relationships between ten lineages of fescues based on the analysis of nuclear rDNA ITS sequences. Thirty two representatives of most native Western Mediterranean subgenera and sections of Festuca s.l. have been included in this survey in order to establish the evolutionary links between known groups of fescues (subg. Schedonorus, subg. Festuca sect. Festuca and sect. Aulaxyper) and other related Festuca groups that have been poorly studied or that are analyzed here for the first time (subg. Drymanthele, subg. Festuca sect. Subbulbosae, sect. Eskia, sect. Pseudatropis, sect. Scariosae, sect. Pseudoscariosa). Phylogenetic analysis identified two different clades, the “broad-leaved” Festuca and the “fine-leaved” Festuca, using Dactylis, Poa, Deschampsia, Secale, and Brachypodium as outgroups. The “broad-leaved” Festuca clade shows the consecutive sister divergence of the groups: i) the Subbulbosae pro parte clade (some Festuca paniculata s.l. ...

Steinernema boemarei n. sp. (Nematoda: Steinernematidae), a new entomopathogenic nematode from southern France

A new entomopathogenic nematode, Steinernema boemarei n. sp., is described from southern France. Morphological, molecular (28S and ITS rDNA sequence data) and cross-hybridisation studies were used for diagnostics and identification purposes. Both molecular and morphological data indicate that the new species belongs to the 'glaseri-group' of Steinernema spp. Key morphological diagnostic traits for S. boemarei n. sp. include the presence of prominent deirids (cervical papillae) on adult males, the morphology of the spicules and gubernaculum, and the arrangement of the 23 genital papillae of the first generation males. Additionally, morphometric traits of the third-stage infective juvenile, including total body length (mean 1,103 micron), tail length (mean 86 micron), location of the excretory pore (mean 91 micron), and D% (mean 63), E% (mean 106) and H% (mean 41) values are definitive. In addition to these morphological characters, analysis of both 28S and ITS rDNA sequences depict this Steinernema species as a distinct and unique entity.

Molecular biological characterization of bursaphelenchus xylophilus and bursaphelenchus mucronatus in Korea

Pine wood nematode (PWN), Bursaphelenchus xylophilus, is a causal organism to induce pine wilt disease (PWD) in many varieties of pine trees. PWD was first introduced to Korea in 1988 but, the damage has been dramatically increased since 2000. Recently PWD is newly reported in Korean pine tree (Pinus koraien‐sis) and is considered one of the most important forest diseases in Korea. Fifteen isolates of B. xylophilus, 2 isolates of B. mucronatus, and 6 unidentified Bursaphelenchus spp. were collected from different geographical locations and hosts in Korea. All the isolates were cultured in fungal medium and nematodes were harvested for further experiment. First, all the isolates were characterized by both ITS and D2D3 rDNA sequence analysis. Template DNA was prepared by DNA extraction from single female nematode. ITS and D2D3 region were amplified by PCR and followed by cloning and sequence. As a result, all the sequences of ITS and D2D3 from B. xyophilus isolates were identical and there is no intraspecific variation. However, 2 genotypes of B. mucronatus were found, which one from P. thunbergii was East Asian type and the other one from P. koraiensis was European type. ITS‐RFLP phenotype was also proposed to discriminate different species and genotypes and 5 enzymes, Hinf I, Alu I, Msp I, Hae III, and Rsa I. were selectively treated.

Molecular data indicate that Rhytidhysteron rufulum (ascomycetes , Patellariales) in Costa Rica consists of four distinct lineages corroborated by morphological and chemical characters

Rhytidhysteron rufulum is a poorly known, common, pantropical species, capable of utilizing different substrata and occupying diverse habitats, and is the only species of its genus in Costa Rica. We have employed molecular, morphological, and chemical data to assess the variability and differentiation of R. rufulum in Costa Rica, including sites from the Pacific and Atlantic coast. Phylogenetic analyses of nuclear ITS rDNA sequences revealed the presence of four distinct lineages in the R. rufulum complex. Re-examination of the morphology and anatomy showed differences between these lineages in ascomatal, ascal, and ascospore size that have previously been regarded as intraspecific variations. In addition, there was a correlation between molecular phylogenies and chemical components as determined by hplc and nuclear magnetic resonance (NMR). Two lineages (clades I and II) produced the palmarumycins MK-3018, CJ-12372, and CR 1, whereas clade III produced dehydrocurvularin, and clade IV unidentified compounds. Our results based on a polyphasic approach contradict previous taxonomic interpretations of one morphologically variable species.

Endosporium, a new endoconidial genus allied to the Myriangiales

A new endoconidial genus, Endosporium gen. nov., is reported from Alberta, Canada. Two species are described: Endosporium populi-tremuloidis Tsuneda sp. nov. (type species) isolated from a heavily colonized bud of Populus tremuloides Michx., and Endosporium aviarium Tsuneda sp. nov. isolated from the skin of Bombycilla garrulus (L.) (Bohemian waxwing) and a twig of Populus balsamifera L. This genus is morphologically similar to Phaeotheca in forming black, slow-growing colonies (conidiomata) containing numerous, conidiogenous, cellular clumps, but different in that (i) colonies possess aerial, determinate hyphae on the surface; (ii) mature colonies eventually collapse to release a mixture of conidiogenous cellular clumps, endoconidia, and blastic conidia in slimy liquid; and (iii) endoconidia are hyaline. Phylogenetic analyses of nuclear rDNA SSU, LSU, and ITS sequences indicate that Endosporium is phylogenetically distant from other endoconidial taxa, including Phaeotheca, and is most closely related to the Myriangiales (Dothideomycetes). Similarities in stroma and conidioma development as well as ecology between the two taxa suggest that Endosporium can be accommodated within this order, making it the first endoconidial and first black meristematic genus reported in the Myriangiales.

RDNA-ITS sequence analysis of pathogens of cucumber downy mildew and cucumber powdery mildew

To determine the pathogens of cucumber downy mildew and cucumber powdery mildew by molecular marker, we amplified and sequenced the rDNA-ITS region of the pathogens of cucumber downy mildew and cucumber powdery mildew collected from the Shanghai region. The intra-/interspecific sequence difference was analyzed by rDNA-ITS sequence. The results show that the length of rDNA-ITS1 and rDNA-ITS2 of cucumber downy mildew’s pathogen was 141 bp and 406 bp, respectively, with GC contents of 41.13% in ITS1 and 46.8% (Minhang and Jinshan District, sm1 and sm2) or 46.55% (Pudong District, sm3) in ITS2. The rDNA-ITS sequence was intraspecific conservation. The interspecific difference was related with their kin relationship. The pathogen of cucumber downy mildew was identified as Pseudoperonospora cubensis by molecular marker. The length of rDNA-ITS1 and rDNA-ITS2 of cucumber powdery mildew’s pathogen was 136 bp and 89 bp, respectively, with GC contents being 59.56% and 66.29%, and rDNA-ITS sequence being highly conservative in this study that was the same as Sphaerotheca cucurbitae. But the sequence difference between the strains in the Shanghai region in this study with S. fuliginea was 4.5%, which was identified by morphology. It is suggested that the pathogen of cucumber powdery mildew should be further clarified and determined.

Prosthecium species with Stegonsporium anamorphs on Acer

Data from microscopic morphology, single-spore cultures, and DNA analyses of teleomorphs and anamorphs support the recognition of five species of Prosthecium with Stegonsporium anamorphs on Acer: P. acerinum sp. nov., the teleomorph of S. acerinum; P. acerophilum comb. nov., formerly known as Dictyoporthe acerophila; P. galeatum comb. nov., originally described as Massaria galeata; P. opalus sp. nov.; and P. pyriforme sp. nov., the teleomorph of S. pyriforme s. str. The morphology of both type specimens and freshly collected material was investigated. The teleomorphs have brown ellipsoidal ascospores with five distosepta and often a longitudinal distoseptum. The anamorphs of all species described here belong to Stegonsporium; their connection to the Prosthecium teleomorphs was demonstrated by morphology and DNA sequences of single spore cultures derived from both ascospores and conidia. The anamorphs and teleomorphs of all five Prosthecium species are described and illustrated by LM images, and a key to these species is provided. As perceived from this work, S. pyriforme is restricted to Europe and does not occur in North America, whereas S. acerinum is restricted to North America, not found in Europe. The host associations given in the literature are revised and evidence is provided that only A. opalus, A. pseudoplatanus, and A. saccharum are confirmed hosts of Prosthecium with Stegonsporium anamorphs. Molecular phylogenetic analyses of tef1, ITS rDNA, and partial nuLSU rDNA sequences confirm that the species with Stegonsporium anamorphs are closely related to P. ellipsosporum, the generic type species. Stilbospora macrosperma is confirmed as the anamorph of P. ellipsosporum by DNA data of single spore isolates obtained from both ascospores and conidia.

Classification of <i>Rhizoctonia</i> spp. using rDNA-ITS sequence analysis supports the genetic basis of the classical anastomosis grouping

Currently, rDNA-ITS sequence analysis seems to be the most appropriate method for comprehensive classification of Rhizoctonia spp. Our previous review article was concerned with detailed analysis of multinucleate Rhizoctonia (MNR), and the current review complements the previous one with detailed analysis of binucleate Rhizoctonia (BNR) (teleomorphs: Ceratobasidium spp. and Tulasnella spp.) and uninucleate Rhizoctonia (UNR) (teleomorph: C. bicorne). Data of all the appropriate BNR and UNR accumulated in GenBank were analyzed together in neighborjoining (NJ) trees supplemented with percent sequence similarity within and among the anastomosis groups (AGs) and subgroups. Generally, the clusters of the isolate sequences supported the genetic basis for the AG based on hyphal fusion anastomosis. Comprehensive interrelationships among all the currently available MNR, BNR, and UNR groups and subgroups in GenBank were subsequently analyzed in NJ and maximum-parsimony (MP) trees, showing the genetic relatedness among the different groups and indicating possible bridging groups between MNR, BNR, and UNR. The review also indicates serious inaccuracies in designation of sequences of some isolates deposited in GenBank. Several additional teleomorph genera with Rhizoctonia spp. anamorphs have also been reported in the literature. However, as they have not been intensively studied, there were no available data on their rDNA-ITS sequences that could be included in this review.

Molds Isolated from Pet Dogs

Pet dogs have been considered to be involved in the contamination of indoor air by serving as a source of providing molds at houses. Currently, information on the molds originated from pet dogs is rarely available in Korea. The present study was carried out to obtain basic information on the fungi present on pet dogs. For this, fungal isolation was performed to the skin and hairs of 70 pet dogs at different houses and veterinary hospitals. A total of 44 fungal isolates were obtained from skin (27 isolates) and hairs (17 isolates) of the dogs investigated. Based on the observation of mierostruetures and colony morphology, and the ITS rDNA sequence analysis, the fungal isolates were identified at the level of genus. The identified isolates belong to the genera of Alternaria, Aspergillus, Beauveria, Chrysosporium, Cladosporium, Penicillium, Scopuiariopsis, and Tricltoderma. Among these genera, Aspergillus (25%), Cladosporium (23%) and Penicillium (20.5%) were 3 major genera. 63% of the 44 isolates showed color changes on dermatophyte test medium (DTM). When we tested the growth ability of 44 isolates at 37°C, 45% of the isolates were able to grow. These results show that pet dogs could carry fungi having a potentiality of affecting on human health.

Cylindrocyclin A, a New Cytotoxic Cyclopeptide from Cylindrocarpon sp.

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Genetic diversity, anastomosis groups and virulence of Rhizoctonia spp. from strawberry

Virulent Rhizoctonia spp. isolated from strawberry in Israel belonged to anastomosis groups (AG) of: binucleate Rhizoctonia (BNR) AG-A, AG-G, AG-K and AG-F, and to multinucleate Rhizoctonia (MNR) AG 4 subgroup HG-I. In addition, a soil isolate of AG 4 subgroup HG-III was also found to be virulent on strawberry. None of the Israeli isolates obtained in the present study belonged to BNR AG-I, or other MNR AGs. In the cluster analysis of rDNA-ITS sequences, all of the isolate sequences consistently clustered according to their known AGs and subgroups. One AG-F cluster included sequences of 10 strawberry isolates, while another AG-F cluster included sequences of two isolates submitted to GenBank. Additional work is needed to determine whether the isolates of these two clusters may belong to different AG-F subgroups. The current virulence bioassay used for Rhizoctonia spp. isolates on strawberry is based on inoculation of stolon-derived daughter plants with the isolates and estimation of the reduction in plant biomass, rather than on specific distinct disease severity symptoms. The duration of this test is relatively long (ca. 5 weeks or more) and the availability of daughter plants from runners is naturally limited to a certain season. Among the possible alternative methods evaluated in the present study (inoculation of fruits or seedlings developed from germinated strawberry seeds), the method based on seedlings was best. This method has a potential to replace the currently used stolon-daughter plant inoculation bioassay for testing virulence of strawberry root pathogens. This is the first report indicating that Rhizoctonia spp. isolates that belong to AG-F, AG-K, AG 4 HG-I and AG 4 HG-III are virulent to strawberry.