Mycologia Iranica
Volume:11 Issue: 1, Winter and Spring 2024

This study presents scientific research on Fusarium redolens (Wollenweber). A systematic search of the Scopus database from 1956 to 2023 yielded 201 indexed documents.  F. redolens is an emerging pathogen with a significant impact on pulse crops. Population growth, especially in developing countries, creates a primary problem: food availability, especially protein sources. Chickpeas are an important crop in western Iran, especially in Kermanshah province. Until 2019, most studies attributed chickpea yellowing and root rot to Fusarium oxysporum and Fusarium solani, respectively. To manage this crop, previous recommendations included planting cereals such as barley and wheat due to the presence of F. oxysporum formae speciales in the soil. However, F. redolens has now been identified as the major cause of chickpea yellowing and root rot, especially in the western provinces. This Fusarium species has been isolated from 54 species of 50 genera and 29 plant families, with the highest frequency observed in Fabaceae, Poaceae and Asteraceae hosts. Given its pathogenicity to wheat and barley and the unknown presence of formae speciales, rotation with these cereals is no longer considered an appropriate management solution.  Further research is needed to develop effective management strategies for the future.

Pleosporalean fungi are important plant pathogens, saprobes, and endophytes found in a wide range of economically important plants. To identify the fungi associated with branch and stem canker symptoms in plants, the gardens and forests of Guilan and Mazandaran provinces were surveyed, and infected plant samples were collected from common hawthorn (Crataegus monogyna), common rue (Ruta graveolens), and oriental persimmon (Diospyros kaki) plants during the autumn of 2021. Fungal strains were isolated and purified by common procedures, and then were morphologically identified. Molecular identification of the fungal strains was performed using the sequence data of the ITS rDNA region. Based on the combined data, three fungal genera and their related species belonging to the order Pleosporales including Acrocalymma walkeri from oriental persimmon, Setophaeosphaeria badalingensis from common rue, and Tremateia chromolaenae from common hawthorn, were identified and characterized. All these three species are new to the funga of Iran. In addition, Diospyros kaki, Crataegus monogyna, and Ruta graveolens have been reported as new hosts (matrix nova) for the respective identified fungal taxa worldwide

Diaporthe cinerascens is a significant plant pathogen that causes canker disease in fig trees. This pathogen is notably dominant in major fig-production areas in Iran, as well as in other fig-producing countries such as Bulgaria, USA (California), Canada, and Italy. In the present study, six Inter-Simple Sequence Repeats (ISSR) markers were used to investigate genetic diversity among representative D. cinerascens isolates, selected based on the variety of their host cultivars, aggressiveness, and morphological features. The discriminating power of each ISSR marker was assessed using 10 parameters including effective multiplex ratio, expected heterozygosis, observed heterozygosity, polymorphic information content, marker index, resolving power, Nei's diversity, Shannon index, polymorphic percentage, and allele number. Among them, M1 primer was the best to detect the variability of the D. cinerascens isolates. The isolates exhibited a high degree of genetic similarity, as evidenced by Jaccard’s similarity coefficients, which ranged from 79% to 100%. Despite the high values of pairwise Jaccard's similarity coefficient among the isolates (at least 79% similarity), they were grouped into four distinct genetic clusters, based on Principal Coordinate Analysis (PCoA) analysis. The observed grouping pattern was found to be partially influenced by their geographical origins and the specific fig cultivars from which the isolates were recovered. Based on ISSR fingerprinting, we provided genetic evidence regarding the clonal structure of D. cinerascens. These results could be critical to understanding Diaporthe canker epidemiology and adopting sustainable management practices for the disease.

Taxonomy and phylogeny of Erysiphe sect. Erysiphe (Erysiphaceae, Helotiales) in Iran was revised. One hundred samples from the University of Guilan Mycological Fungarium (GUM) and the fungal reference collection of the Ministry of Jihad-e Agriculture (IRAN), as well as newly collected specimens during 2019–2021, were investigated using morphology and ITS-LSU rDNA sequence analysis. Based on our findings, Erysiphe sect. Erysiphe has 22 accepted and two unknown species in Iran viz.: E. aquilegiae, E. betae, E.  buhrii, E.  caulicola, E.  circaeae, E.  convolvuli, E.  cruchetiana, E. cruciferarum, E.  heraclei, E. howeana, E.  limonii, E. lycopsidis, E.  malvae, E.  mayorii,  E.  medicaginis, E.  paeoniae, E. pisi, E. polygoni, E. punicae, E. rumicicola, E.  sedi, E. urticae. E. sedi and E. paeoniae are new records for the funga of Iran. In addition, Mesostemma kotschyana (Caryophyllaceae) is reported as a new host for E. buhrii. The occurrence of potential cryptic species on Urtica spp. is discussed as well

In spring 2023, during a survey of Eucalyptus trees (Eucalyptus camaldulensis Dehn.) in Jiroft, Kerman Province, Iran, leaves with leaf spot symptoms were collected. Fungal colonies with similar growth patterns were isolated from symptomatic leaves. The recovered isolates were identified based on the combination of morphological features and sequence data of the ITS-rDNA and part of the translation elongation factor 1-alpha (tef-1a) gene as Pestalotiopsis biciliata. Pathogenicity tests were carried out by using detached leaves and seedlings of Eucalyptus, fulfilling the Koch's postulates. To our knowledge, this is the first report of P. biciliata for the Iranian Funga and also the first report of the pathogenicity of this species on E. camaldulensis in Iran.

Heavy metals, such as cadmium (Cd), ingress into the human body via the food chain through animal and plant agro-chemicals, inducing epigenetic modifications, DNA harm, genetic mutations, and carcinogenesis. This investigation aimed to scrutinize and identify fungi tolerant to Cd toxicity in aqueous solutions using the poisoned food technique. Thirty fungal strains cultured under three distinct concentrations of Cd (0, 100, and 300 mg/L), with subsequent quantitative evaluation of mycelial growth. Cluster analysis delineated two fungal groups comprising 19 and 11 strains. Group II demonstrated superior performance across most evaluated traits compared to Group I, with exceptions noted for biomass at 0 mg/L and stress tolerance index (STI) at 300 mg/L Cd. Consequently, Group II was deemed the superior cohort. Within Group II, Epicocum nigrum exhibited the highest biomass production (2.17 and 1.35 g/L, respectively) at both 0 and 100 mg/L Cd concentrations, alongside the highest STI (2.18 and 0.43, respectively) at Cd levels of 100 and 300 mg/L. Conversely, Clonostachys rogersoniana displayed the highest biomass production (0.46 g/L) at a Cd concentration of 300 mg/L, coupled with the lowest percentage of inhibition (PI) (-11.35 and -31.40%, respectively) at Cd toxicity levels of 100 and 300 mg/L. Hence, the 11 strains within Group II, particularly E. nigrum and C. rogersoniana, exhibit promise for further investigation concerning their efficacy in Cd removal from aqueous solutions.

Cellulases and xylanases are hydrolytic enzymes that randomly cleave the β-1, 4 backbones of the cellulose and arabinoxylans of wheat flour and are widely used in the bakery industry as a dough texture improver in the formulations of flour products. Creating novel sources of a microbial strain using induced gamma irradiation can increase enzyme production for bakery industrial usage. According to this, Co60 gamma irradiation has been used to develop a mutant strain of Trichoderma afroharzianum. Trichoderma mutants were isolated, and the qualitative and quantitative screening were used to evaluate the extracellular enzyme production with the wheat bran waste as a substrate. The best Trichoderma mutant isolate was identified using the DNA barcoding method. The highest xylanase activities were observed in the superior mutant isolate of Trichoderma afroharzianum NAS107-M82, which is approximately 3.3 times higher than its parent strain. The electrophoretic pattern of proteins showed that the exo-glucanase I, endo-glucanase III, and the xylanase I enzymes hydrolyzed the wheat bran, synergistically. Overall, gamma irradiation-induced mutation could be an expedient technique to access such superior mutants for the bioconversion of wheat bran wastes to xylanase enzyme.

In a study on taxonomy and pathology of fungal species associated with oak trees showing canker, defoliation, dieback, gummosis, wilting, and decline symptoms in Zagros forests, we found 12 isolates morphologically resemble Nigrospora spp., with the same ISSR fingerprinting patterns generated by M13 primer. Thus, a representative isolate IRAN 4332C was selected for phylogenetic analyses based on ITS, tef1, and tub2 DNA sequence data. Multigene phylogenetic analyses characterized isolate IRAN 4332C as Nigrospora shadeganensis. Weak leaf necrosis and weak irregular wood necrosis were recorded in pathogenicity tests performed on leaves and stems of two-year-old Quercus brantii seedlings in vitro and under greenhouse conditions.

Rose (Rosa spp.) is a widely cultivated perennial flowering plant grown in open fields and under controlled greenhouse conditions. This study focused on the isolation and characterization of a pathogen affecting Rosa hybrida plants in the Najafabad and Lenjan counties of Isfahan Province, Iran. Infected stems and crowns were collected from the greenhouses between July 2022 and September 2023. The cultivars affected were Samurai and Tanja. Fungal isolation was achieved, followed by morphological characterization and molecular identification by DNA sequencing of the internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (TEF1-α), and β-tubulin (TUB). Pathogenicity tests confirmed the ability of the isolate to induce stem canker and leaf spot symptoms in healthy Samurai and Tanja cultivars of rose (R. hybrida) plants, thereby fulfilling Koch's postulates. The isolates were identified as Neopestalotiopsis clavispora by the morphological and molecular characteristics. To our knowledge, this study reports the first identification of N. clavispora as a pathogen causing canker disease and dieback on roses in Iran, emphasizing the need for effective management strategies to protect rose health and mitigate economic losses in the ornamental horticultural sector.

The Comoclathris genus belongs to the Pleosporaceae family (Dothideomycetes, Pezizomycotina, Ascomycota), with most species being saprophytes. In the present study, Comoclathris typhicola was isolated from Typha latifolia (Typhaceae, Poales) exhibiting leaf spot symptoms. The species was described using PDA, MEA, and OA culture media, and its molecular identification was confirmed through sequencing of the large subunit RNA polymerase II (RPB2) gene. This is the first report of this species in Iran.

In a study on taxonomy of mycotoxigenic fungi associated with raisins and other dried fruits including apricots, apples and white mulberries, and the traditional food Terkhêna in Mahabad, west of Iran, 33 isolates resembling members of the genus Rhizopus were collected. These isolates were placed in two distinct clusters based on DNA fingerprinting patterns generated by primer (GTG)5. A representative isolate from each cluster was selected for phylogenetic analysis. Based on ITS phylogeny, two representative isolates IRAN 5249C and CJA OGh31 were identified as Rhizopus arrhizus which has previously been reported from soil and clinical samples in Iran. To our knowledge, it is the first report of R. arrhizus on dried fruits apricot and white mulberry and the traditional food Terkhêna around the globe. To clarify the taxonomy of R. arrhizus, we recommend more investigation on the phylogeny of this species using multigene phylogenetic analyses.

Sour cherry trees in Guilan Province are infected by at least two fungi that cause leaf spots and shot holes namely Wilsonomyces carpophilus and Pruniphilomyces circumscissus. In the late summer and early autumn of 2023, a leaf spot in the form of small purple-red to brown lesions about 1-3 mm in size was seen on the sour cherry trees in Sumaehsara County, Guilan Province, Iran. Mature conidiomata, acervuli, were formed frequently on the abaxial leaf surface at the center of each lesion, producing asexual conidia in white masses. Morphological and molecular studies showed that Blumeriella jaapii is associated with the sour cherry leaf spot disease. This is the first report on this fungus and the first attempt to sequence the ITS-nrDNA as the primary barcode of Blumeriella jaapii in Iran.