سید اکبر خداپرست

Within the framework of the Mycology research laboratory's program at the University of Guilan focusing on the identification and DNA barcoding of powdery mildew fungi (Erysiphaceae, Ascomycota) from Iran, a powdery mildew specimen on Helichrysum was collected from Zanjan-Tarom road and subjected for morphological and molecular identification. Although this species morphologically resembles Leveillula helichrysi, and some other closely related species such as L. taurica complex, the ITS sequence differentiates this fungus from the sequences of L. helichrysi and L. taurica available in GenBank. We suggest this collection may represent a new species or new haplotype within L. helichrysi. Therefore, until we obtain more samples and sequence the type material, we report this fungus as Leveillula cf. helichrysi from Iran.

The most important goal in all crop breeding programs is to increase yield, and yield improvement requires the use of efficient statistical methods to identify superior genotypes. In determining the superiority of genotype, in addition to high yield, yield stability in different environments must also be considered.Biplot analyses are good tools for selecting superior genotypes and to increase efficiency in selection.

In the present study GGE biplot method was used for assessment yield and yield stability of 130 genotypes of soybean under two environmental conditions, natural conditions and disease stress (artificial induction of charcoal rot disease), were evaluated in a simple lattice design with two replications at Seed and Plant Improvement Research Institute (SPII), Karaj, Alborz province, Iran, during 2014 and 2015 (four environments).

The results of combined analysis of grain yield/plant revealed that effects of location, genotype and interaction of genotype × location were significant. The results of stability analysis using GGE-biplot method revealed that the first (Genotype) and second (genotype × environment interaction) components explained 70% and 14%, respectively, and the both components 84% of the total variation, which indicates a good validity of the biplot in explaining the variations of genotypes and genotype × environment interaction (G + GE). Polygonal biplot showed that the genotype 66 had the highest grain yield in environment E2 (disease conditions in 2014) and E4 (disease conditions in 2015), however, the genotypes 1, 3, 5, 43, 63, 66, 75, 76, 77 and 89 had a good combination of stability and yield.

Some of these genotypes such as genotype 66 did not show any signs of charcoal rot in both experimental years, they also had a good grain yield.

In this study, we re-examined a collection from IRAN herbarium that was identified as Erysiphe deutziae on Deutzia gracilis. Precise morphological studies supplemented with rDNA ITS sequencing disclosed that the powdery mildew on this collection is a member of the genus Arthrocladiella. Moreover, re-examination of host plant confirmed that host plant has been misidentified and it belongs to the genus Lycium. Arthrocladiella is a monotypic member of family Erysiphaceae (Ascomycota, Helotiales), which has only been reported from Lycium spp. (Solanaceae). According to our findings, Arthrocladiella mougeotii infects Lycium sp. in Iran and is reported as a new genus for Iranian Mycobiota.

Since the publication of the latest monograph of powdery mildews by Braun and Cook in 2012, no comprehensive revision has been done to check the accuracy of the hitherto recorded species of the genus Erysiphe in Iran. In this study, we present a taxonomic revision of Erysiphe sect. Uncinula in Iran using morphological traits of voucher specimens and ITS-LSU rDNA sequence analysis. Thirty-eight voucher specimens were obtained from the University of Guilan Mycological herbarium (fungarium, GUM) and the Fungus Reference Collection of Herbarium Ministerii Iranici Agriculturae (IRAN), as well as newly collected specimens during 2019–2021, were examined morphologically. The ITS sequences were generated for 26 selected specimens, and the LSU sequences were generated for 16 specimens. Two ITS sequences of E. paradoxa (OM574846 and OM574845), as well as ITS and LSU sequences of E. celtidis (OM574855 and OM574834, respectively), were sequenced for the first time in this study. Precise morphological observations and molecular analyses of Iranian specimens changed the number of accepted species of Erysiphe sect. Uncinula from six taxa in 2009 to 10 taxa in 2021. All species identified from Iran are here described and illustrated. A key to species of Erysiphe sect. Uncinula in Iran is also provided.

Downy mildew is one of the most important diseases of cucurbits in the world and Iran. The development of the disease was investigated in a commercial variety (Sakata® F1 Hybrid Saso), three hybrids and eight pure lines of cucumber, four pure squash lines, and one commercial cultivar of watermelon (Sakata® F1 Charleston Gray 243) in two consecutive years (2017 and 2018 spring and summer) at the experimental field of the University of Guilan, Iran to identify the sources of resistance. Plants were regularly inspected until the downy mildew symptoms appeared. The disease was measured using standard scale and Image J software at five stages in the plant growing season. Comparison of disease progress curves, final severity of the disease, and area under the disease progress curve (AUDPC) showed that cucumber B10 and A12 pure lines were the most susceptible and resistant in both years, respectively. None of the squash lines were infected in the first year, but in the second year, two lines showed the disease symptoms, and the severity of the disease in these lines was close to each other. The commercial cultivar of watermelon was not infected in both years.

During the study on boxwood blight from 2016 to 2017, some isolates of Pseudonectria were isolated from boxwood leaves and branches. Fungi were isolated and purified using conventional methods. According to the morphological characteristics and ITS rDNA sequences, two species of Pseudonectria viz. P. buxi and P. foliicola were identified. Moreover, the pathogenicity of these two species under laboratory and greenhouse conditions was examined. None of the species were able to produce disease on the healthy plant leaves, and leaf wounds were necessary to establish the infection. According to our knowledge, this is the first report of Pseudonectria species on boxwood from Iran.

Linum usitatissimum, known as flax, is grown all around the world. Powdery mildew is a common disease on this crop so that this disease has been described from most flax-growing areas of the world. Clear symptoms of powdery mildew were observed on the field of different flax cultivars of Seed and Plant Improvement Institute of Iran in 2020 growing season. The causal pathogen of flax powdery mildew was identified as Podosphaera lini based on the morphological features and the nuclear ribosomal DNA internal transcribed spacer sequence. This is the first documented report of P. lini from flax in Iran.

Athelia rolfsii is a globally dispersed pathogenic fungus, causing white root rot disease in many crops and horticultural plants. In this study, 90 isolates were collected from three provinces of Guilan, Mazandaran and Golestan in northern Iran. Eighteen isolates were selected for sequence analyses based on their host, sampling sites and Mycelial Compatibility Groups (MCG). Translation elongation factor 1-α(tef1-α), β-tubulin (tub2) genes and rDNA large subunit (LSU) were partially amplified and sequenced in order to conduct phylogenetic analyses. Approximately, all Iranian isolates clustered together in both tef1-α and LSU phylogenetic trees. However, after deletion of ambiguous sites, no variations were observed in tub2 sequences. ISSR and SCoT were also used to investigate the genetic structure of the population. Results of the molecular variance analysis (AMOVA) showed that 70 and 30% of the observed variance corresponded to the difference between and within the populations, respectively. According to these findings, we suggest that mating between populations would be less likely and thus, gene flow is restricted.

Investigating the vegetation of protected areas and its harmful agents such as Erysipelas fungi is an important issue for evaluating such areas. The aim of the present study was to investigate the biodiversity of Erysipelas fungi and their hosts in the central and peripheral zones of Oshtorankouh Mountain. The analysis could the basis for further studies and provide basic biometric information of plants in terms of infection with pathogens in these areas.

In order to study the biodiversity of these fungi and their host plants, 10 plots in the central zone and the same plot number of peripheral areas in Oshtorankouh Mountain were selected and infected plants and fungal species were identified using their morphological characteristics. Then, the biodiversity indices of Simpson and Shannon, uniformity indices of Eviness, and richness indices of Margalef and Mannheicks were estimated for these species by PAST software. After that, the relative abundance percentages and total abundance of these species were estimated. The correlation between these indices was analyzed using the Leven test.

Eighteen pathogenic fungi species belonging to 6 genera on 40 plant species from 15 genera were identified. The results of the study showed that the highest relative abundance of fungi species belonged to Leveillula the Astreaceae family for plants. There was no significant difference between biodiversity, richness, and uniformity indices of the studied areas. But, there was a difference between the elevation classes in terms of the relative abundance of pathogenic fungi. The correlations between diversity and richness indices of infected plants and between these two indices in pathogenic fungi were also positive and significant (p <0.01).

Most plant species hosts are new records for Iran or even in the world. Damages by such fungi along with other harmful factors and the critical situation of the area occupied by these species threaten the plants of the region.

Exploring the enzymatic capabilities of fungi is of great importance to better understand their ecological roles and improving their manifold usage in industry. Therefore, rapid and reliable screening methods to evaluate fungal enzymatic potentials are needed. In this study, 76 fungal strains were isolated and identified from insect pests from citrus plantations in Guilan province, northern Iran. All the strains belonged to Akanthomyces and Lecanicillium (Ascomycota: Hypocreales). Plate assay methods were applied to investigate fungal ability to produce the following enzymes: Endo-1,4-β-glucanase (CM-cellulase, endoglucanase and endocellulase), β-Glucosidase, Cellobiodydrolase, pectinase and laccase. The results showed that the majority of the strains were able to produce at least one of these enzymes. The cellulolytic activity was found in 33 % and laccase activity was detected in 11 % of all strains tested.  Interestingly, the enzymatic ability of strains identified as A. muscarius and A. lecanii, were generally different, likely confirming their taxonomic position.

The Erysiphaceae are obligatory and biotrophic fungal parasites that infect many landscape and ornamental plants which results in reduction of beauty and marketability of these plants. This study was performed to identify powdery mildew fungi on landscape and ornamental plants in four provinces (Isfahan, Chaharmahal & Bakhtiari, Markazi and Lorestan) of Iran. Consequently, 24 powdery mildew taxa on 28 host species were collected during 2017 to 2019. According to our findings,Golovinomyces asperifolii (on Nonea sp.) and Podosphaera euphorbiae-helioscopiae (on Pedilianthus sp.) are new records to Iran mycobiota. Three plant species including Coreopsis sp., Catharanthus roseus and Fragaria vescaare new hosts for powdery mildew fungi of Iran. Moreover, Podosphaera xanthii on Dahlia sp. is reported for the first time from Iran.

In this study, we report some Ascomycete genera from Nectriaceae, Botryosphaeriaceae, Cryphonectriaceae and Hypocreaceae families from Guilan province, Iran. Cultural and morphological characteristics and sequence information of rDNA ITS and translation elongation factor 1-α encoding gene (tef1) were used for identification. Among isolates studied in this research, six species viz. Microthia havanensis, Lasiodiplodia hormozganensis, Lasiodiplodia parva, Thyronectria austroamericana, Trichoderma cf. chromospermum and Trichoderma cf. longibrachiatum are reported as new or less known species for the region. As a result, two genera viz. Thyronectria (Nectriaceae) and Microthia (Cryphonectriaceae) and two species (Lasiodiplodia parva and Trichoderma cf. chromospermum)are new reports for Iran mycobiota.

Athelia rolfsii is a globally distributed soil-borne fungal pathogen causing root rot disease in many crops. In order to study the genetic diversity of this fungus, 90 isolates were collected and isolated from Guilan, Mazandaran and Golestan provinces (North of Iran). Genetic diversity of these isolates was investigated using Mycelial Compatibility Groups tests (MCG) and ISSR and SCoT markers. In this study, nine MCG groups were identified. The MCG3 group (with 36 members) was the most frequent in terms of the number of isolates and the most diverse group in terms of host domain (due to infection of eight host species). This group (MCG3) was also the only group that isolated from specimens in all three provinces. The dendrogram derived from cluster analysis of ISSR primers divided the isolates into four groups at a similarity level of 57%. The dendrogram obtained from cluster analysis of SCoT primers placed the isolates in a similarity level of 59% in three groups. Based on the results of both markers, Golestan isolates (except two isolates) were separated from Guilan and Mazandaran isolates. However, the presence of these two isolates in a separate cluster along with the isolates of Guilan and Mazandaran provinces was consistent with the results of MCG grouping. The results of this study showed that, these two types of markers are useful to differentiate isolates based on geographic regions.

Aquatic hyphomycetes equipped with a rich array of extracellular enzymes are involved in bioremediation of anthropogenic pollutants, plastics, aromatic contaminants and petroleum hydrocarbons. The current study contributes to the knowledge of Iranian aquatic hyphomycetes. Sampling was conducted in Anzali lagoon, Gilan province, Iran during 2017. Among 55 fungal isolates obtained during this study, eight species including Arthrobotrys oligosporus, Ceratorhiza hydrophila, Fusarium cf. ensiforme, F. incarnatum species complex, Myrmecridium schulzeri, Paecilomyces variotii, Sarocladium subulatum, and Volutella citrinella were identified based on their morphological characteristics. Furthermore, three species assigned to the genera Arthrobotrys, Fusarium and Sarocladium remained unidentified. Molecular studies using mainly ITS, LSU and SSU rDNA and in some cases β-tubulin (tub2) and translation elongation factor 1-a (tef1) determined the phylogenetic position of the isolates among closely related species. The occurrence of members of Fusarium, Sarocladium, and Ceratorhiza, known as rice disease agents, in freshwater ecosystems is interesting. This is the first report of aquatic hyphomycetes communities in Anzali lagoon, Iran. In this study, Sarocladium subulatum, Myrmecridium schulzeri, and Volutella citrinella are reported for the first time for Iran.

Neoerysiphe nevoi on Crepis kotschyana and Hedypnois rhagadioloides, Leveillula linariae on Linaria melanogramma and Golovinomyces asterum var. moroczkovskii on Symphyotrichum squamatum are newly reported from Iran. Nine new host-powdery mildew combinations are reported from Iran: Neoerysiphe galii − Galium aparine; Podosphaera xanthii − Phlox paniculata; Erysiphe syringae-japonicae − Ligustrum sp.; Erysiphe cruciferarum − Barbarea sp.; Golovinomyces depressus − Centaurea depressa; Golovinomyces montagnei − Notobasis syriaca; Golovinomyces orontii − Papaver somniferum; Golovinomyces cynoglossi − Lithospermum arvense; Leveillula picridis − Launaea acanthodes. The following host plants are reported as Matrix nova for their related fungal species: Crepis kotschyana and Hedypnois rhagadioloides for Neoerysiphe nevoi; Phlomis herba-venti subsp. kopetdaghensis for Neoerysiphe galeopsidis; Euphorbia hebecarpa and Papaver macrostomum for Leveillua taurica s.str.; Paracaryum rugulosum for Golovinomyces cynoglossi; Euphorbia tithymaloides for Podosphaera euphorbiae; Iranecio paucilobus for Leveillula lappae.

Two powdery mildew species have been collected from Iran. For the first time, Erysiphe magnifica on Magnolia sp. was identified from Iran based on morphological and molecular characteristics. Erysiphe corylacearum was collected for the second time in the country and reported for the first time from Guilan province. There are some polymorphisms in ITS-rDNA sequences of E. corylacearum between Iranian and GenBank sequences. This polymorphism is worth of attention for better understanding of the taxonomy of the species and role of ITS sequences for species delimitation. The ITS sequence of the Iranian specimen of E. magnifica was 100% identical to four ITS sequences of E. magnifica in GenBank. Morphologically, E. magnifica was characterized by curved, flexuous and relatively long foot cells, whereas, foot-cells of conidiophores have been reported in the literature as relatively short. According to these observations, it is recommended to check as many characters as possible for identification of morphologically and molecularly closely related species.

Nine Dictyuchus isolates were obtained from floating and decaying twigs and leaves in Anzali lagoon, Anzali County, Guilan province, Iran. They are interestingly distinguished from current Dictyuchus species by the presence of dictyoid and achlyoid type of zoospore discharge, abundant fusiform and spherical gemma, and the absence of any sexual apparatus. In addition, phylogenetic analyses of the internal transcribed spacer (ITS) region of the nuclear rDNA and cytochrome c oxidase subunit I (cox1) gene sequences using Maximum likelihood method indicate its novelty. We preferred not to introduce the isolates as new species due to low number of and sometimes unreliable sequences and lack of type species and suggested to verify Dictyuchus sterilis which has been excluded before. We discussed about taxonomy of the genus in details and provided a revised key to the species. In addition, it was shown that sterility in vitro might be common in this genus.