y. ghosta

Sclerotinia sclerotiorum (Lib.) de Bary is a globally distributed necrotrophic fungus that infects a wide range of plants. The management of this pathogen in crops typically requires a combination of methods, with resistant cultivars and fungicide applications being the most commonly used strategies. It is essential to comprehend the evolutionary potential of S. sclerotiorum in a specific region in order to effectively control this pathogen, conduct germplasm evaluations, and develop resistant cultivars. An in-depth analysis of aggressiveness variation, diversity and distribution of mycelial compatibility groups (MCGs), and the occurrence of sexual reproduction via the methods, such as mating type genotype determination can provide valuable insights into the genetic diversity, and evolutionary potential of this fungus. In West Azarbaijan province, S. sclerotiorum poses a significant threat to sunflower and cabbage crops, causing considerable losses. Nevertheless, there is a dearth of research that compares the aggressiveness diversities and MCG of fungal isolates from these two hosts. Additionally, there is presently no information available regarding the mating type genotypes of the pathogen populations in the province and other regions of the country. This study was conducted to investigate, and compare MCGs and aggressiveness diversity in S. sclerotiorum populations from sunflower, and cabbage fields in West Azarbaijan province. The research also aimed to identify mating type genotypes, and compare their aggressiveness diversity.

This study examined 136 S. sclerotiorum isolates collected from sunflower, and cabbage fields in Urmia, Salmas, and Khoy in West Azarbaijan province, Iran. The mating type alleles of the isolates were determined using specific primers. Isolates in which either Inv+ MAT (inversion positive) or Inv– MAT allele was detected were classified as Inv+ MAT or Inv– MAT genotype, respectively. Isolates showing amplification of both alleles were categorized as heterokaryon genotypes. The MCGs of isolates were determined by pairing them in all possible combinations on potato dextrose agar supplemented with McCormick food color. The number of MCGs was determined both for total isolates and for each of the populations. To evaluate MCG diversity, MCG richness (ratio of different MCGs) was calculated for the populations. The level of aggressiveness of 80 specific isolates was evaluated by inoculating them on detached leaves of sunflower and cabbage, and then measuring the diameters of the resulting lesions five days after the inoculation. Lesion diameter data were normalized via logarithmic transformation, and analyzed using a general linear model in Minitab 17 software. Means were compared using Tukey–Kramer honestly significant difference (HSD) test at a significance level of P < 0.05.

The specific primers successfully amplified MAT alleles in the studied isolates, leading to the identification of three genotypes, Inv– MAT, Inv+ MAT, and heterokaryon, within 136 S. sclerotiorum isolates. These genotypes were distributed as follows: 74 isolates (54.41%) were Inv– MAT, 22 isolates (16.18%) were Inv+ MAT, and 40 isolates (29.41%) were heterokaryon. While all three MAT genotypes were present across all geographical regions, and on both host plants, the Inv– MAT genotype was the most frequent genotype in all regions and on sunflower, while heterokaryon genotype was more common among cabbage isolates. A total of 17 MCGs, designated MCG1 to MCG17, were identified in the 136 isolates. Eleven of these MCGs had multiple isolates, with MCG1, MCG2, and MCG3 having the highest number of isolates, respectively. MCG1 and MCG6 were found in all three studied regions and on both hosts, while MCG4 was detected in Urmia and Salmas on both hosts. Other MCGs with multiple isolates were restricted to one or two regions and one host only. The total MCG richness among all 136 isolates was 12.5%, with cabbage isolates exhibiting a greater MCG richness of 18.6% than sunflower isolates, which had a smaller MCG richness of 12.9%. Salmas had the highest level of diversity among the regional populations, with a mean MCG richness of 29.6%. A significant difference in lesion diameter on detached leaves of sunflower and cabbage was observed among the isolates. Significant differences were observed in the lesion diameters of isolates from hosts, MAT genotypes, and MCGs, all at a statistically significant level of 1%. The isolates from cabbage, and those with a heterokaryon genotype demonstrated higher aggressiveness compared to sunflower isolates, and other MAT genotypes, respectively.

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.

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.

Exserohilum species are plant or human pathogens, saprobes or endophytes mostly associated with grasses including cultivated cereals. At present, 11 phylogenetic species have been accepted in this genus worldwide. In this study, we introduce a novel species, Exserohilum persianum from Festuca sp. (Poaceae, Poales) showing necrotic leaf lesions based on morphological characteristics and sequence data obtained from the internal transcribed spacer (ITS‒rDNA) region, parts of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and translation elongation factor-1 alpha (TEF1) genes. A detailed morphological description, illustration and comparison with closely allied species are provided.

Oomycete species occupy many different environments and many ecological niches. The family Saprolegniaceae from Oomycota includes widely distributed water molds which usually behave as saprophytes on plants and animal debris. Members of some species may also be pathogenic for plants and fish. Oomycete species identification based on DNA is well established, but DNA barcoding with cytochrome c oxidase subunit I (COXI) and II (COX II) are a relatively new approach. In this study, 57 isolates were obtained from water samples in mazandaran province, Iran. After morphological identification by morphological keys, ITS, COXI , and COX II gene regions of 10 representatives of the isolates were sequenced and 3 genera and 6 species (Newbya recurva, Achlya bisexualis, Dictyuchus monosporus, Saprolegnia ferax, S. bulbosa , and S. debaryana) were identified through BLASTn in NCBI gene bank. The results described in this paper were indicated that except for ITS, COXI and COXII sequencing could also be valuable resources to Saprolegniaceae identification. Except for S. ferax, other described species were new reports for oomycete biota of Iran.

In a recent survey on apple orchards showing stem canker, dieback and decline symptoms in West Azerbayjan province, Iran, several fungal isolates with typical characteristics of the genus Cytospora were obtained. Combination of morphological and cultural characteristics and phylogenetic analysis of internal transcribed spacer region of the nrDNA (ITS-rDNA) and parts of large subunit of ribosomal DNA (LSU), actin (ACT) and RNA polymerase II (RPB2) genes were used to accurate delimitation of fungal species. Four Cytospora species viz. C. chrysosperma, C. germanica, C. paratranslucens and C. salicina were identified. Pathogenicity tests were conducted on detached branches of ‘Golden delicious’ and ‘Red delicious’ apple cultivars. Isolates of C. salicina caused characteristic lesions on both ‘Golden delicious’ and ‘Red delicious’ apple cultivars, while isolates of C. chrysosperma, C. germanica and C. paratranslucens were only pathogenic on ‘Red delicious’ apple cultivar. Re-isolation and identification of the inoculated fungi confirmed Koch’s postulates. This study indicated the presence of different Cytospora species causing apple canker, dieback and decline disease in the studied area. Cytospora germanica and C. salicina are reported for the first time as causal agents of apple canker disease. Moreover, these species are reported as new records for the mycobiota of Iran.

In order to study of cabbage leaf spot disease in Damavand region, Tehran province, Iran, symptomatic cabbage leaves (Brassica oleracea var. capitata) were collected during the late summer and fall of 2017. Twenty-one isolates with the main characteristics of the genus Alternaria were isolated from lesions on the cabbage leaves. Based on morphological characteristics and phylogenetic analysis using multi-gene sequences, they were identified as Alternaria telliensis. Pathogenicity tests were conducted on cabbage leaves under greenhouse conditions and characteristic lesions were formed on inoculated leaves. Re-isolation of the inoculated fungus from the treated leaves confirmed Koch’s postulates. Based on the available information, this is the first occurrence of A. telliensis as a new species and pathogen to cabbage plants in Iran.

Mycophenolic acid (MPA) is a fungal metabolite possessing antiviral, antifungal, antibacterial, antitumor and anti-psoriasis activities. It is being used as an immunosuppressive agent in kidney, heart and liver transplantation patients. In the presence of MPA, the proliferation of the B and T lymphocytes is inhibited. The MPaB and MPaE genes reside in a 25 kb gene cluster in the genome of Penicillium brevicompactum. In this study, the genomic DNA was extracted from P. brevicompactum grown on potato dextrose (PD) medium. To amplify the MPaB and MPaE fragments, the specific primers were designed using Gene Runner software according to P. brevicompactum IBT23078 sequence database under HQ731031.1 accession number. The amplified MPaB and MPaE genes were cloned in the PTG19-T PCR cloning vector and transformed to Escherichia coli (E. coli) top 10 competent cells. The insertion of MPaB and MPaE in the PTG19-T cloning vector was further confirmed by PCR. The MPaB and MPaE amplification produced amplicons of 1477 and 780 (nt), respectively, with the same length according to the MPaB and MpaE genes deposited in the GenBank. However, the alignment results showed some differences at nucleotide and amino acid levels, implying a new strain of P. brevicompactum.

In the continuation of studies on Alternaria species, some 500 isolates were obtained from seeds, soil and plant parts from various localities of Iran. Prior to morphological examination, pure cultures were obtained by single conidium and single chain methods. Descriptions for each taxon are based on cultures developed on potato carrot agar. Inoculated plates were incubated at 23-25°C under a cool-white fluorescent light/dark cycle of ca. 8/16 hrs. Microscopic examinations were carried out after 5-7 days. Conidiophores, conidia and sporulation patterns were studied and recorded. Seven species of Alternaria are introduced and described in the present investigation, five of which (A. chlamydospora, A. cinereariae, A. infectoria, A. mouchaccae and A. porri) are new to the mycoflora of Iran. Other two species, A. brassicae and A. japonicae, that have been reported from Iran previously, are described here with.