MYCOLOGIA IRANICA
Year:2023 | Volume:10 | Issue:2|Papers Count:12

Distoseptispora generally is  regarded as a saprobic lignicolous fungal genus and presently comprises 64 species. Of these, 42 of them were found in freshwater and 22 in terrestrial habitats. Most Distoseptispora species are reported from China and Thailand, which are subtropical and tropical regions. In this study, we report Distoseptispora bambusae as a saprobic fungus on decaying leaves of common bamboo (Bambusa vulgaris) based on morphological characteristics and sequence data of the ITS‒rDNA region. Distoseptispora bambusae was described, illustrated, and its morphology and phylogenetic relationships with similar Distoseptispora species were discussed. To the best of our knowledge, this is the first report of D. bambusae on common bamboo for the mycobiota of Iran and the Middle East.

In this study, the phylogeny and taxonomy of Erysiphe sect. Microsphaera was investigated for the first time in Iran. This study was based on morphological examination and rDNA (ITS+ LSU) sequencing. We examined 80 voucher specimens from the Fungus Reference Collection of Herbarium Ministerii Iranici Agriculturae (IRAN) and the University of Guilan Mycological fungarium (including specimens newly collected during 2019–2021). Seventy-nine sequences covering 20 species were generated. E. hyperici was not available for this study. Sequencing of E. begoniicola and E. tortilis failed. Based on our findings, E. coluteae and E. crispula were sequenced for the first time in this study. Records of E. erlangshanensis and E. castaneigena from Iran were rejected. The number of accepted species in sect. Microsphaera increased from 13 in 2009 to 23 in this study. Erysiphe crispula on Astragalus spp. is reported here for the first time, and Syringa vulgaris has been reported as a new host of E. syringae japonicae in Iran. Furthermore, DNA barcodes, colored plates, digital illustrations, and identification keys of all E. sect. Microsphaera in Iran are provided herein.

Ascomycota includes a large number of species that lack a known sexual stage but have a hidden potential for sexual reproduction, among which is Aspergillus flavus, an opportunistic aflatoxin-producing pathogen. The sexual stage of this heterothallic fungus results from crossing between strains with opposite mating types that belong to different vegetative compatibility groups. Here, twenty A. flavus Iranian isolates were investigated for heterothallism and sexual reproduction. The mating type genes MAT1-1 and MAT1-2 were explored using specific primers and multiplex PCR. The results indicated an equal frequency of mating types (1:1) in the investigated A. flavus isolates, indicating heterothallism, and possible sexual reproduction. The cross-cultures on Mixed Cereal Agar (MCA) and Aspergillus Complete Medium (ACM) induced the sexual phase. After 6 to 11 months, 33.16% of the crosses led to sexual reproduction and the sexual reproductive organ of the fungus appeared at the contact lines of the crosses. Scanning Electron Microscopy (SEM) analyses revealed multiple asci and ascospores, which were produced in the pseudoparenchymatous stromata. Ascospore production was more efficient in ACM than in the MCA. Our findings place the Iranian A. flavus in the genus Petromyces, as Petromyces flavus.

Due to the variety of vegetation and high humidity, the Northern provinces of Iran are the habitat of many medicinal mushrooms. Genetic variation of medicinal mushrooms in Iran is poorly studied. 30 isolates of Trametes versicolor were collected from different localities in Guilan, Golestan, and Mazandaran provinces (North of Iran). The genetic diversity was evaluated by ISSR marker. 86 bands were observed using eight polymorphic primers. Cluster analysis showed that the isolates divided into 18 groups at a level of 0.22 similarity coefficient. SI indices were 0.335, 0.305 and 0.217 in Guilan, Golestan, and Mazandaran populations respectively. 96% genetic variation was observed within populations. The diverse geographic origin of the isolates is an influential factor in the high intra-population genetic diversity of the fungus.

In this study, twenty-one isolates of the genus Colletotrichum with straight conidia were isolated from leaf spots on wild Poaceae plants in three provinces of Iran, including East Azarbaijan, Golestan, and Guilan. Based on morphology, the isolates belonged to three morphotypes. Representative isolates were studied by a polyphasic approach, which included morphology, and phylogeny inferred from multi-locus sequences including the nuc rDNA ITS1-5.8S-ITS2 (ITS), partial sequences of the β-tubulin (TUB2), and actin (ACT) genomic regions. Three distinct species were identified namely C. chrysophilum, C. destructivum and C. orientalis.  Colletotrichum chrysophilum and C. orientalis are new records for the Funga of Iran. This study provides new insights into the host range and geographical distribution of these identified species.

The genus Trichoderma consists of globally distributed fungi. Among them, T. harzianum, is one of the most commonly collected Trichoderma species, which had been known as an aggregate species. In the present study, using a Trichoderma selective medium, 20 isolates belonging to 5 Trichoderma species of the Harzianum clad were isolated from soil samples collected from diverse geographical regions of Khorramabad County, Iran. Comparing the cultural and phenotypic criteria combined with molecular tests of the tef1 gene sequences of isolated fungi, five species namely, T. afroharzianum, T. atrobrunneum, T. guizhouense, T. harzianum and T. pholiotae were identified and their descriptions and figures are presented in this paper. T. harzianum had the highest frequency among the 5 species. T. pholiotae is reported for the first time from Iran.

The necrotrophic fungus Parastagonospora nodorum, the causal agent of stagonospora nodorum blotch (SNB), is responsible for significant economic losses of wheat worldwide. Despite the presence of a high number of TF-encoding genes within the genome of P. nodorum, very little is known about their expression profile and their functions during cellular and biological processes. In this study, ten putative TF genes in P. nodorum isolate SN15 were selected, four of which shared homology with well-known fungal TFs involved in pathogenesis, and the other six genes were located in putative secondary metabolite biosynthetic gene clusters (BGCs). The expression profile of these candidate TF genes was investigated using both semi-quantitative and quantitative RT-PCR assays under in vitro and in planta conditions. The results revealed that six candidate TF genes exhibited the highest expression levels in the minimal media lacking both nitrogen and carbon sources as well as during the early stages of infection. These findings suggest that these six candidate TFs may play an important role in the pathogenicity of P. nodorum.

Persian oak is the most important forest tree in Fars province (Iran). In order to identify the composition of Alternaria species associated with healthy and declined Persian oak trees in Fars Province, Iran, fungal isolates were recovered from twigs, trunks and leaves of healthy and declining Persian oak trees from early September to late March 2021-2022. Fungal species were identified based on both morphological and as well as molecular characteristics of the DNA sequence data of the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and plasma membrane ATPase genes. In total, 29 Alternaria isolates were obtained, which were identified as Alternaria alternata, Alternaria consortialis and Alternaria chlamydospora. Alternaria alternata showed the highest frequency approximately 51.72% and were isolated from both healthy and declining oak trees. Alternaria chlamydospora and A. consortialis were obtained only from healthy oak trees without declining symptoms with 41.38% and 6.89% frequencies,, respectively. Pathogenicity tests were conducted using all isolates in three replicates. Inoculation of different Alternaria alternata, Alternaria consortialis and Alternaria chlamydospora isolates on Persian oak seedlings did not show any symptoms after 60 days in greenhouse conditions. This is a new report of Alternaria species including A. alternata, A. consortialis and A. chlamydospora as endophytic fungi on Persian oak tree in Fars province of Iran.

Trichoderma species are widely used as biological agents to control plant diseases. Chitinases are crucial in mycoparasitism and defense against other fungi or arthropods. In this study, we evaluated 41 amino acid sequences related to the Chit18-5 gene from four sections and 15 Trichoderma species. The conserved domains, motifs, and phylogenetic tree were analyzed using the InterProScan database, COBALT tool, MEME V5.5.1 software, ClustalW algorithm, and MEGA11 software. The results showed that the gene region under investigation can effectively distinguish different Trichoderma species and is an effective tool for optimizing biocontrol strategies. This study highlights the potential of exploring genetic diversity as a means of identifying new solutions for managing pests and diseases in agriculture. The putative motifs of chitinase proteins identified in this study may participate in Trichoderma antagonistic activities

Verticillium wilt of stone fruit trees caused by Verticillium dahliae occurs worldwide and causes serious economic losses. Control of Verticillium is difficult and costly due to its wide host range and resistant soil-borne microsclerotia. Also, increased concerns about agrochemicals have encouraged the development of biocontrol strategies. In this study, we evaluated antagonistic fungi for biocontrol of V. dahliae in vitro and greenhouse. A total of 85 endophytic and rhizospheric fungal isolates of peach and other stone fruit trees were isolated in the west Azarbaijan province, Iran. The identified fungi included Alternaria, Aspergillus, Aureobasidium, Clonostachys, Cryptococcus, Fusarium, Penicillium, and Trichoderma. The potential control of the isolates was initially evaluated by a dual culture assay. Furthermore, the antagonistic activity of fungi metabolites on the germination of microsclerotia both in vitro and in the soil was evaluated. In total, Trichoderma asperellum AE66 showed the highest inhibitory activity (73.85%) and was selected for greenhouse experiments. In the greenhouse assay on peach, T. asperellum AE66 not only reduced the progress of Verticillium wilt but also its severity. Moreover, the plant growth was promoted. These findings suggest that biocontrol provides a potentially effective strategy for the management of Verticillium wilt.

During the study of fungal taxa of gramineous plants, a hyphomycetous fungus with typical characteristics of the genus Spegazzinia was isolated from leaves of Brachypodium sp. (Poaceae), collected in Mazandaran province, Iran. The fungal species was determined as Spegazzinia tessarthra based on the combination of morphological characteristics and phylogenetic analysis of the internal transcribed spacer (ITS-rDNA) region and a partial region of the translation elongation factor 1-alpha gene (tef1-α) sequences. In this study, we introduce S. tessarthra, saprobic on Brachypodium sp. leaves, as a new record for the Funga of Iran and Brachypodium sp. as a new substrate for the species. The description and illustrations of Spegazzinia tessarthra from Iran have been provided, and its morphology and phylogenetic relationships with other species of Spegazzinia have been discussed. To our knowledge, this is the first report of a species from the genus Spegazzinia in Iran, and further research is needed to determine the diversity of Spegazzinia species in the country.

In a survey of fungal species associated with walnut kernel rot symptoms, a white fungal mycelial mass was observed in feces and larval debries of codling moths (Cydia pomonella) on walnut kernels in East and West Azerbaijan provinces in 2022. Infected samples were examined under a stereo microscope, white mycelial mass together with fungal spores were taken using a sterile needle, and pure cultures were established using the single spore method. Morphological characteristics were examined on potato dextrose agar (PDA) and malt extract agar (MEA) culture media in the dark at 21°C after one week of incubation. To confirm the identity of the isolated fungi, the ITS rDNA genomic region of representative isolates were amplified using a universal primer set (ITS1 and ITS4) via polymerase chain reaction, and PCR products were sequenced. Based on the combination of morphological features and sequencing data, the isolates were identified as Quambalaria cyanescens. Colonies grew slowly, reaching a diameter of 11-12 mm on PDA and MEA after one week, and produced a purple pigment in the medium. Conidiophores are undifferentiated from vegetative hyphae and conidiogenous cells are holoblastic with sympodial proliferation. The conidia are usually ovoid or pear-shaped, transparent and 2-8 × 1.5-2.5 µm. Quambalaria cyanescens is a rare basidiomycete species of the order Microstromatales, which also has a yeast phase. The pathogenic potential of the two isolates of Q. cyanescens was evaluated on larvae of Ephestia kuehniella; however, the survival rate of larvae treated with different concentrations of Q. cyanescens spores was the same as that of untreated control larvae, and it can be concluded that the Q. cyanescens isolates were not pathogenic to E. kuehniella larvae. To the best of our knowledge, this is the first report on the association of Q. cyanescens with feces and larval debries of codling moths on walnut kernels.