Fungi in the sea fan <Emphasis Type="Italic">Gorgonia ventalina</Emphasis>: diversity and sampling strategies

Fungal communities from gorgonians have been poorly documented and most studies of these communities have lacked defined sampling strategies. The objectives of this study were: (1) to estimate fungal diversity in Gorgonia ventalina; (2) to compare two sampling and tissue processing strategies: tissue fragments of different sizes vs. homogenized tissue. A total of seven genera and fourteen species of fungi were isolated on culture medium and identified by sequencing the nrITS. All but one species were new reports. In both treatments Aspergillus and Penicillium were the most common genera isolated. Most species isolated from fragments were not observed from homogenized tissue and vice versa. Reducing the size fragment increased significantly the number of species isolated per fragment. To better estimate fungal diversity in sea fans a strategy is proposed that combines sampling of small tissue fragments with homogenized tissue, since each technique yielded fungal species not detected by the other.     

Culture-dependent and culture-independent diversity of <Emphasis Type="Italic">Actinobacteria</Emphasis> associated with the marine sponge <Emphasis Type="Italic">Hymeniacidon perleve</Emphasis> from the South China Sea

In this report, the diversity of Actinobacteria associated with the marine sponge Hymeniacidon perleve collected from a remote island of the South China Sea was investigated employing classical cultivation and characterization, 16S rDNA library construction, 16S rDNA-restriction fragment length polymorphism (rDNA-RFLP) and phylogenetic analysis. A total of 184 strains were isolated using seven different media and 24 isolates were selected according to their morphological characteristics for phylogenetic analysis on the basis of their 16S rRNA gene sequences. Results showed that the 24 isolates were assigned to six genera including Salinispora, Gordonia, Mycobacterium, Nocardia, Rhodococcus and Streptomyces. This is the first report that Salinispora is present in a marine sponge from the South China Sea. Subsequently, 26 rDNA clones were selected from 191 clones in an Actinobacteria-specific 16S rDNA library of the H. perleve sample, using the RFLP technique for sequencing and phylogenetic analysis. In total, 26 phylotypes were clustered in eight known genera of Actinobacteria including Mycobacterium, Amycolatopsis, Arthrobacter, Brevibacterium, Microlunatus, Nocardioides, Pseudonocardia and Streptomyces. This study contributes to our understanding of actinobacterial diversity in the marine sponge H. perleve from the South China Sea.     

Antimicrobial potentials of endophytic fungi residing in <Emphasis Type="Italic">Quercus variabilis</Emphasis> and brefeldin A obtained from <Emphasis Type="Italic">Cladosporium</Emphasis> sp.

Among 67 endophytic fungi isolated from Quercus variabilis, 53.7% of endophytic fungal fermentation broths displayed growth inhibition on at least one test microorganism, such as pathogenic fungi (Trichophyton rubrum, Candida albicans, Aspergillus niger, Epidermophyton floccosum, Microsporum canis) and bacteria (Escherichia coli, Bacillus subtilis, Pseudomonas fluorescens). Moreover, 19.4% of strains showed a broader antimicrobial spectrum, such as Aspergillus sp., Penicillium sp., Alternaria sp., 20.9% of strains showed strong inhibition (+++) to pathogenic bacteria, while only 7.5% displayed that to test fungi. The most active antifungal strain I(R)9-2, Cladosporium sp. was selected and fermented. From the broth, a secondary metabolite, brefeldin A was obtained. This is the first report on the antimicrobial potentials of endophytic fungi residing in Q. variabilis and isolation of brefeldin A produced by Cladosporium sp.     

Fungal load in <Emphasis Type="Italic">Bradysia agrestis</Emphasis>, a phytopathogen-transmitting insect vector

Larvae of Bradysia agrestis, a phytopathogen-transmitting insect vector in East Asia, were sampled from geographically (ecologically) segregated regions to identify their intestinal fungal flora. A total of 24 fungal strains were isolated from the insect vectors and selected based on morphological differences. In addition, 38 fungal strains were isolated from the ulcerated parts of invaded host plants by the same method, revealing the impact of vector fungal flora on their host plants. For molecular identification of the fungi, internal transcribed spacer (ITS) regions were amplified and sequenced. Their sequences were compared with sequences of other fungal strains obtained from NCBI GenBank, and their phylogeny was determined. The dominant fungal genera in the insect vector were Penicillium (25%), Aspergillus (21%), and Cladosporium (13%). In plant scar lesions, most fungal isolates belonged to the genera Fusarium (31.6%), Phoma (7.8%), Didymella (7.8%), and Epicoccum (7.8%). Fungal genera in vectors or host plant lesions differed by study site. Furthermore, diversity indices by study site showed clear differences based on Margalef’s richness (2.06, 2.40, 3.04), and Menhinick’s (1.89, 2.12, 2.53), and Simpson’s indices (0.14, 0.07, 0.07). In addition, common fungal strains in insect vectors were found to be closely related to members of the genera Cladosporium, Penicillium, or Aspergillus. Among these strains, those showing the highest homology with Aspergillus terreus, which regarded as beneficial fungal genera could be considered ideal paratransgenesis candidates. Some other fungal strains from vectors or ulcerated plant parts from each study site after B. agrestis invasion may be harmful in terms of plant disease or agrifood safety. This study provides information on the fungal microbiota of B. agrestis, an emerging problem in East Asia, and proposes paratransgenesis candidates to control this insect vector. Furthermore, potential transferable pathogens or commensal fungi were revealed by comparing the fungal biota between the insect gut and the ulcerated parts of the invaded host plants.     

Antimicrobial Activity and Biodiversity of Endophytic Fungi in <Emphasis Type="Italic">Dendrobium</Emphasis><Emphasis Type="Italic">devonianum</Emphasis> and <Emphasis Type="Italic">Dendrobium thyrsiflorum</Emphasis> from Vietman

Endophytic fungi are rich in orchids and have great impacts on their host plants. 53 endophytes (30 isolates from Dendrobium devonianum and 23 endophytic fungi from D. thyrsiflorum) were isolated, respectively, from roots and stems of Dendrobium species. All the fungi were identified by way of morphological and/or molecular biological methods. 30 endophytic fungi in D. devonianum were categorized into 11 taxa and 23 fungal endophytes in D. thyrsiflorum were grouped into 11 genera, respectively. Fusarium was the dominant species of the two Dendrobium species in common. Antimicrobial activity of ethanol extract of fermentation broth of these fungi was explored using agar diffusion test. 10 endophytic fungi in D. devonianum and 11 in D. thyrsiflorum exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among 6 pathogenic microbes (Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus). Out of the fungal endophytes isolated from D. devonianum and D. thyrsiflorum, Phoma displayed strong inhibitory activity (inhibition zones in diameter >20 mm) against pathogens. Epicoccum nigrum from D. thyrsiflorum exhibited antibacterial activity even stronger than ampicillin sodium. Fusarium isolated from the two Dendrobium species was effective against the pathogenic bacterial as well as fungal pathogens. The study reinforced the assumption that endophytic fungi isolated from different Dendrobium species could be of potential antibacterial or antifungal resource.     

Endophytic fungi from rhizomes of <Emphasis Type="Italic">Paris polyphylla</Emphasis> var. <Emphasis Type="Italic">yunnanensis</Emphasis>

About 63 fungal endophytic isolates were separated from rhizomes of Paris polyphylla var. yunnanensis, which is a traditional medicinal plant mainly distributed in China. The isolates were characterized and grouped based on the culture characteristics and the morphology of colony growth and conidia. Eleven representative ones were selected for further taxonomical identification. Five genera namely Fusarium, Gliocladiopsis, Gliomastix, Aspergillus and Cylindrocarpon were identified on the basis of their morphological characterizations. Of them, the most frequent genus was Fusarium (i.e. Ppf1, Ppf3 and Ppf14). Their ITS-rDNA sequences were compared with those available in the GeneBank databases to obtain the closest related species by BLAST analysis as well as to analyze their phylogenetic affiliation. The isolates were identified as Gliocladiopsis irregularis (Ppf2), Plectosphaerella cucumerina (Ppf4), Padospora sp. (Ppf6), Gliomastix murorum var. murorum (Ppf7), Aspergillus fumigatus (Ppf9), Pichia guilliermondii (Ppf10), Neonectria radicicola (anamorph: Cylindrocarpon) (Ppf12) and one uncultured mycorrhizal ascomycete (Ppf13) separately based on their morphological and molecular features. The molecular characters of the endophytic fungi were basically coincident with their morphology. The broad diversity and taxonomic spectrum were exhibited by the endophytic fungi from P. polyphylla var. yunnanensis.     

Phylogenetic diversity of culturable fungi associated with the Hawaiian Sponges Suberites zeteki and Gelliodes fibrosa

Sponges are well documented to harbor large amounts of microbes. Both culture-dependent and molecular approaches have revealed remarkable bacterial diversity in marine sponges. Fungi are commonly isolated from marine sponges, yet no reports on phylogenetic diversity of sponge-inhabiting fungi exist. In this report, we investigated the phylogenetic diversity of culturable fungi from the Hawaiian alien marine sponges Suberites zeteki and Gelliodes fibrosa. A total of 44 independent isolates were recovered from these two sponge species, representing 7 orders and 22 genera of Ascomycota. The majority (58%) of fungal isolates from S. zeteki resided in the Pleosporales group, while the predominant isolates (52%) from G. fibrosa were members of the Hypocreales group. Though differing in fungal species composition and structure, culturable communities of these two sponges displayed similar phylogenetic diversity. At the genus level, only two genera Penicillium and Trichoderma in the Eurotiales and Hypocreales orders, respectively, were present in both sponge species. The other genera of the fungal isolates were associated with either S. zeteki or G. fibrosa. Some of these fungal genera had been isolated from sponges collected in other marine habitats, but more than half of these genera were identified for the first time in these two marine sponges. Overall, the diversity of culturable fungal communities from these two sponge species is much higher than that observed in studies of marine sponges from other areas. This is the first report of phylogenetic diversity of marine sponge-associated fungi and adds one more dimension to our current understanding of the phylogenetic diversity of sponge-symbiotic microbes.     

Phylogenetically Diverse Cultivable Fungal Community and Polyketide Synthase (PKS), Non-ribosomal Peptide Synthase (NRPS) Genes Associated with the South China Sea Sponges

Compared with sponge-associated bacteria, the phylogenetic diversity of fungi in sponge and the association of sponge fungi remain largely unknown. Meanwhile, no detection of polyketide synthase (PKS) or non-ribosomal peptide synthase (NRPS) genes in sponge-associated fungi has been attempted. In this study, diverse and novel cultivable fungi including 10 genera (Aspergillus, Ascomycete, Fusarium, Isaria, Penicillium, Plectosphaerella, Pseudonectria, Simplicillium, Trichoderma, and Volutella) in four orders (Eurotiales, Hypocreales, Microascales, and Phyllachorales) of phylum Ascomycota were isolated from 10 species marine sponges in the South China Sea. Eurotiales and Hypocreales fungi were suggested as sponge generalists. The predominant isolates were Penicillium and Aspergillus in Eurotiales followed by Volutella in Hypocreales. Based on the conserved Beta-ketosynthase of PKS and A domain of NRPS, 15 polyketide synthases, and four non-ribosomal peptides synthesis genes, including non-reducing and reducing PKSs and hybrid PKS–NRPS, were detected in these fungal isolates. A lateral gene transfer event was indicated in the comparison between the phylogenetic diversity of 18S rRNA genes and β-ketoacyl synthase domain sequences. Some fungi, especially those with PKS or NRPS genes, showed antimicrobial activity against P. fluorescens, S. aureus and B. subtilis. It was the first time to investigate PKS and NRPS genes in sponge-associated fungi. Based on the detected antibiotics biosynthesis-related PKS and NRPS genes and antimicrobial activity, the potential ecological role of sponge-associated fungi in the chemical defense for sponge host was suggested. This study extended our knowledge of sponge-associated fungal phylogenetic diversity and their potential roles in the chemical defense.     

The endophytic fungi from wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

In order to study the species composition of endophytes from wheat healthy plants in Buenos Aires Province (Argentina) and to determine their infection frequencies from leaves, stems, glumes and grains, wheat plants were collected from five cultivars at five growth stages from crop emergence to harvest. A total of 1,750 plant segments (leaves, stems, glumes and grains) were processed from the five wheat cultivars at five growth stages, and 722 isolates of endophytic fungi recovered were identified as 30 fungal genera. Alternaria alternata, Cladosporium herbarum, Epicoccum nigrum, Cryptococcus sp., Rhodotorula rubra, Penicillium sp. and Fusarium graminearum were the fungi that showed the highest colonization frequency (CF%) in all the tissues and organs analysed. The number of taxa isolated was greater in the leaves than those in the other organs analysed.     

Fungal species residing in the sclerotia of <Emphasis Type="Italic">Polyporus umbellatus</Emphasis>

Sclerotia of Polyporus umbellatus is a traditional Chinese herb. The sclerotia can survive in soils for long time and their growth depends upon a symbiotic association with Armillariella mellea. But it is unclear whether other fungi reside or play a role in the sclerotia. In this study, wild sclerotial samples were collected from seven provinces, which span southwest to northeast China. A total of 148 fungal isolates were recovered from the sclerotia of P. umbellatus and classified into 19 morphological taxa. Seventeen belonged to five genera: Fusarium, Eurotium, Penicillium, Geomyces and Mucor. The fungi found within the sclerotia varied depending on the province from which they were collected. The possible role of these fungi is discussed.     

New phylogenetic lineages of the <Emphasis Type="Italic">Spirochaetes</Emphasis> phylum associated with <Emphasis Type="Italic">Clathrina</Emphasis> species (Porifera)

Though spirochetes have been repeatedly found in marine sponges and other invertebrates, little attention has been paid to the specificity of this association. This study demonstrates that different genoand morphotypes of spirochetes can reside within the same sponge individual and develop in considerable numbers. Specimens of the calcareous sponge Clathrina clathrus collected from the Adriatic Sea off Rovinj (Croatia) were found to harbor spirochete-like bacteria, which were characterized by scanning electron microscopy (SEM), 16S rRNA gene analysis, and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH). Two novel spirochete sequence types related to the Brachyspiraceae could be retrieved. By use of specifically designed CARD-FISH probes, the C. clathrus-associated sequences could be assigned to a linear and a helical spirochete morphotype. Both were located within the sponge mesohyl and resembled the spirochete-like cells identified by SEM. In addition, from a Clathrina sp., most likely C. coriacea, that originated from Indonesian coastal waters, four different spirochete type sequences were recovered. Two of these also affiliated with the Brachyspiraceae, the other two were found associated with the Spirochaetaceae, one with the genera Borrelia and Cristispira.     

Antimicrobial endophytic fungal assemblages inhabiting bark of <Emphasis Type="Italic">Taxus baccata</Emphasis> L. of Indo-Burma mega biodiversity hotspot

Fungal endophytes were isolated from inner bark of Taxus baccata L., an important source of potent anticancer drug taxol. Bark samples were collected from two locations of Arunachal Pradesh, India, part of the Indo-Burma mega biodiversity hotspot, during two seasons i.e. monsoon and winter. Altogether 77 fungal strains representing 18 genera were isolated from T. baccata bark during the present investigation. The colonizing frequency was recorded as 38.5% and the fungal community comprised of 78% of Hyphomycetes, 5.2% of Coelomycetes, 2.6% of Zygomycetes and Ascomycetes and 9.1% of sterile mycelia. Most common and frequently isolated genera were Fusarium, Penicillium and Aspergillus. Simpson and Shannon diversity indices indicated higher species diversity during monsoon than during winter seasons irrespective of the locations. The two locations harbored 5 to 37 endophyte species and the similarity index was low during winter and high during monsoon. Ethyl acetate extract of fermentation cultures of these fungi were tested for their antimicrobial activity against a panel of human pathogenic Gram-positive and Gram-negative bacteria and fungi. Fifteen fungal isolates out of the isolated strains displayed antimicrobial activity. An endophytic fungus, identified as Fusarium sp. displayed significant antimicrobial activity against all the test pathogens.     

Clavatol and patulin formation as the antagonistic principle of <Emphasis Type="Italic">Aspergillus clavatonanicus</Emphasis>, an endophytic fungus of <Emphasis Type="Italic">Taxus mairei</Emphasis>

Many endophytic fungi are known to protect plants from plant pathogens, but the antagonistic mechanism has rarely been revealed. In this study, we wished to learn whether an endophytic Aspergillus sp., isolated from Taxus mairei, would indeed produce bioactive components, and if so whether (a) they would antagonize plant pathogenic fungi; and (b) whether this Aspergillus sp. would produce the compound also under conditions of confrontation with these fungi. The endophytic fungal strain from T. mairei was identified as Aspergillus clavatonanicus by analysis of morphological characteristics and the sequence of the internal transcribed spacers (ITS rDNA) of rDNA. When grown in surface culture, the fungus produced clavatol (2′,4′-dihydroxy-3′,5′-dimethylacetophenone) and patulin (2-hydroxy-3,7-dioxabicyclo [4.3.0]nona-5,9-dien-8-one), as shown by shown by NMR, MS, X-ray, and EI-MS analysis. Both exhibited inhibitory activity in vitro against several plant pathogenic fungi, i.e., Botrytis cinerea, Didymella bryoniae, Fusarium oxysporum f. sp. cucumerinum, Rhizoctonia solani, and Pythium ultimum. During confrontation with P. ultimum, A. clavatonanicus antagonized its growth of P. ultimum, and both clavatol as well as patulin were formed as the only bioactive components, albeit with different kinetics. We conclude that A. clavatonanicus produces clavatol and patulin, and that these two polyketides may be involved in the protection of T. mairei against attack by plant pathogens by this Aspergillus sp.     

Assessment of mycoflora and infestation of insects,vector of <Emphasis Type="Italic">Aspergillus</Emphasis> section <Emphasis Type="Italic">Flavi</Emphasis>, in stored peanut from Argentina

The occurrence of spoilage fungi and Aspergillus section Flavi populations, the aflatoxins incidence, the role of insects as vectors of mycotoxin-producing fungi and the AFs-producing ability of the isolated species throughout the peanut (Arachis hypogaea L.) storage period were evaluated. Analyses of fungal populations from 95 peanut seed samples did not demonstrate significant differences between the incidences in each sampling period. Aspergillus section Flavi were isolated during all incubation periods. Cryptolestes spp. (Coleoptera: Cucujidae) were collected in August, September and October with 18, 16 and 28% of peanut samples contaminated, respectively. Insects isolated during August showed 69% of Aspergillus section Flavi contamination. A. flavus was the most frequently isolated (79%) from peanut seeds and from insect (59%). The greater levels of AFB₁ were detected in September and October with a mean of 68.86 μg/kg and 69.12 μg/kg respectively. The highest proportion of A. flavus toxigenic strains (87.5%) was obtained in June. The presence of Aspergillus section Flavi and insect vectors of aflatoxigenic fungi presented a potential risk for aflatoxin production during the peanut storage period. Integrated management of fungi and insect vectors is in progress.     

Phylogeny and taxonomy of <Emphasis Type="Italic">Cladosporium</Emphasis>-like hyphomycetes,including <Emphasis Type="Italic">Davidiella</Emphasis> gen. nov., the teleomorph of <Emphasis Type="Italic">Cladosporium s. str.</Emphasis>

A phylogenetic study employing sequence data from the internal transcribed spacers (ITS1, ITS2) and 5.8S gene, as well as the 18S rRNA gene of various Cladosporium-like hyphomycetes revealed Cladosporium s. lat. to be heterogeneous. The genus Cladosporium s. str. was shown to represent a sister clade to Mycosphaerella s. str., for which the teleomorph genus Davidiella is proposed. The morphology, phylogeny and taxonomy of the cladosporioid fungi are discussed on the basis of this phylogeny, which consists of several clades representing Cladosporium-like genera. Cladosporium is confined to Davidiella (Mycosphaerellaceae) anamorphs with coronate conidiogenous loci and conidial hila. Pseudocladosporium is confined to anamorphs of Caproventuria (Venturiaceae). Cladosporium-like anamorphs of the Venturia (conidia catenate) are referred to Fusicladium. Human-pathogenic Cladosporium species belong in Cladophialophora (Capronia, Herpotrichiellaceae) and Cladosporium fulvum is representative of the Mycosphaerella/Passalora clade (Mycosphaerellaceae). Cladosporium malorum proved to provide the correct epithet for Pseudocladosporium kellermanianum (syn. Phaeoramularia kellermaniana, Cladophialophora kellermaniana) as well as Cladosporium porophorum. Based on differences in conidiogenesis and the structure of the conidiogenous loci, further supported by molecular data, C. malorum is allocated to Alternaria.     

Endophytic fungi assemblages from 10 <Emphasis Type="Italic">Dendrobium</Emphasis> medicinal plants (Orchidaceae)

Dendrobium is the largest genus of tropical epiphytic orchid, some of which are traditional Chinese medicinal plants. The therapeutic components varied significantly among species. Endophytic microbes (fungi) hidden in medicinal plants may play an important effect on the overall quality of herb. Investigation of fungal composition in host plants is the first step toward elucidating the relationship endophyte-therapeutic content of herbal medicine. In this study, 401 culturable fungal endophytes were isolated and identified from 10 species of medicinal Dendrobium based on morphological and molecular techniques. The results showed that endophytic fungi from Dendrobium plants exhibited high biodiversity (37 genera, about 80 species). Acremonium, Alternaria, Ampelomyces, Bionectria, Cladosporium, Colletotrichum, Fusarium, Verticillium and Xylaria were the dominant fungal endophytes. Tropical epiphytic orchids appear to vary in degree of host specificity in their endophytic fungi.     

Isolation and characterization of endophytic taxol-producing fungi from <Emphasis Type="Italic">Taxus chinensis</Emphasis>

This study investigated the endophytic fungi diversity of Taxus chinensis and screened the taxol-producing fungi in the host. A total of 115 endophytic fungi isolates obtained from bark segments of T. chinensis were grouped into 23 genera based on the morphological traits and sequence analysis of the internal transcribed spacers (ITS1-5.8S-ITS2), indicating endophytic fungi in T. chinensis are diverse and abundant. Diaporthe, Phomopsis (anamorph of Diaporthe), Acremonium, and Pezicula were the dominant genera, whereas the remaining genera were infrequent groups. The 13 representative species of the distinct genera were capable of producing taxol verified by reverse-phase high performance liquid chromatography (HPLC). Among the taxol-producing fungi, the yield of taxol produced by the Metarhizium anisopliae, H-27 was 846.1 μg l⁻¹ in reformative potato dextrose liquid medium, and the fungal taxol was further validated by mass spectrometry (MS). The taxol-producing fungi (92.3%) were infrequent communities, suggesting that infrequent fungi associated with T. chinensis might be a fascinating reservoir of taxol-generating fungi.     

Diversity of culturable actinobacteria isolated from marine sponge <Emphasis Type="Italic">Haliclona</Emphasis> sp.

This study describes actinobacteria isolated from the marine sponge Haliclona sp. collected in shallow water of the South China Sea. A total of 54 actinobacteria were isolated using media selective for actinobacteria. Species diversity and natural product diversity of isolates from marine sponge Haliclona sp. were analysed. Twenty-four isolates were selected on the basis of their morphology on different media and assigned to the phylum Actinobacteria by a combination of 16S rRNA gene based restriction enzymes digestion and 16S rRNA gene sequence analysis. The 16S rRNA genes of 24 isolates were digested by restriction enzymes TaqI and MspI and assigned to different groups according to their restriction enzyme pattern. The phylogenetic analysis based on 16S rRNA gene sequencing showed that the isolates belonged to the genera Streptomyces, Nocardiopsis, Micromonospora and Verrucosispora; one other isolate was recovered that does not belong to known genera based on its unique 16S rRNA gene sequence. To our knowledge, this is the first report of a bacterium classified as Verrucosispora sp. that has been isolated from a marine sponge. The majority of the strains tested belong to the genus Streptomyces and three isolates may be new species. All of the 24 isolates were screened for genes encoding polyketide synthases (PKS) and nonribosomal peptide synthetases (NRPS). PKS and NRPS sequences were detected in more than half of the isolates and the different "PKS-I-PKS-II-NRPS" combinations in different isolates belonging to the same species are indicators of their potential natural product diversity and divergent genetic evolution.     

Morphology and colonization preference of arbuscular mycorrhizal fungi in <Emphasis Type="Italic">Clethra barbinervis</Emphasis>, <Emphasis Type="Italic">Cucumis sativus</Emphasis>, and <Emphasis Type="Italic">Lycopersicon esculentum</Emphasis>

Clethra barbinervis (Ericales), Cucumis sativus, and Lycopersicon esculentum were grown in soils collected from six different vegetation sites (cedar, cypress, larch, red pine, bamboo grass, and Italian ryegrass), and morphology and colonization preference of arbuscular mycorrhizal (AM) fungi were investigated by microscopic observation and PCR detection. C. barbinervis consistently formed Paris-type AM throughout the sites. C. sativus formed both Arum- and Paris-type AM with high occurrence of Arum-type AM. L. esculentum also formed both Arum- and Paris-type AM but with high occurrence of Paris-type AM. AM diversity within the same plant species was different among the sites. Detected AM diversity from AM spores in different site soils did not consistently reflect AM fungal diversity seen in test plants. Detected families were different, depending on test plants grown even in the same soil. AM fungi belonging to Glomaceae were consistently detected from roots of all test plants throughout the sites. Almost all the families were detected from roots of C. barbinervis and L. esculentum. On the other hand, only two or three families of AM fungi (Archaeosporaceae and/or Paraglomaceae and Glomaceae) but not two other families (Acaulosporaceae and Gigasporaceae) were detected from roots of C. sativus, indicating strong colonization preference of AM fungi to C. sativus among test plants. This study demonstrated that host plant species strongly influenced the colonization preference of AM fungi in the roots.     

Investigation of stored wheat mycoflora,reporting the<Emphasis Type="Italic">Fusarium</Emphasis> cf.<Emphasis Type="Italic">langsethiae</Emphasis> in three provinces of Iran during 2007

Wheat is the most important cereal produced in Iran. A mycological survey was carried out for the first time, on the stored wheat samples in Tehran, East Azarbayejan and Mazandaran provinces in 2007. Exogenous and endogenous fungi, were isolated by the method of flotation with Malachite green agar (MGA 0.25) and Freeze blotter techniques respectively. In this study, 46 species belonging to 23 different genera were isolated.Cladosporium spp. (57.1–89.2%) andAlternaria spp. (82.4–100%) species were the predominant fungal species identified as endogenous mycoflora. The predominant exogenous fungi werePenicillium spp. (78.4–92.8%) andAspergillus spp. (71.4–85.7%) species.Fusarium proliferatum was the most prevalent species ofFusarium isolates.Aspergillus niger (39.4%) andAspergillus flavus (36.7%) were the predominantAspergillus species identified as exogenous mycoflora.Aspergillus flavus (26.6%) was the predominantAspergillus species identified as endogenous mycoflora. Flotation method with MGA 0.25 recommended for isolating of hyaline fungi from wheat cereals. In this study one isolate fromFusarium species was isolated on the basis of morphology and ribosomal internal transcribed spacer classified asFusarium langsethiae but on the basis of partial translation elongation factor-1alpha gene grouped withFusarium sporotrichioides. To our knowledge, this is the first report aboutF. cf.langsethiae in Iran and Asia.