mansoureh mirabolfathy

Cupressus sempervirens L. var. horizontalis is one of the indigenous species of Iran, the natural habitats of which are regarded as significant forest reserves within Iran. In the northern of Iran, cypress trees have commonly been observed in both natural and artificially planted forests. The purpose of this study was to investigate the fungal factors affecting the common cypress tree die back in Hassanabad (Mazandaran province) during the summer of 2023. Study of the affected trees indicated drying in the terminal branches of the trees, blight and necrosis of the upper branches, as well as canker formation on the trunks of common cypress trees. The infected tissues of common cypress trees were cultured on potato dextrose agar medium. Fungal isolates were obtained. Based on the macroscopic and microscopic characters of the isolates they were identified as Diplodia cupressi in the laboratory. To confirm the morphological identification the rDNA sequence data (ITS1-5.8S-ITS2) were obtained using primers ITS1 and ITS4, and nBLAST. The pathogenicity of the fungus was approved on potted cypress seedlings. This study represents the major role of D. cupressi as the causal agent of Common cypress canker in North of Iran. It seems that the climate change and drought conditions provided the favorable environment to outbreak of the disease

Sphaerulina is a genus of fungi which belongs to the family Mycosphaerellaceae in the order Mycosphaerellales. In a survey of leaf-inhabiting fungi associated with trees in Hyrcanian forests, several isolates of the genus Sphaerulina were recovered from leaf spot symptoms of oak trees. Integration of multi-locus phylogenetic analyses (LSU, ITS, actA and tef1) and morphological identification were applied to identify the isolates. The results revealed that, the isolates belong to a species of the genus Sphaerulina, namely, S. quercicola. To the best of author’s knowledge, this is the first report of this species for the funga of Iran.

There is not sufficient information about the effect of neem extract on the growth, sporulation level, and production of aflatoxins by A. flavus. Therefore, the aim of this study was to further investigate the effect of neem seed extract on the production of aflatoxin AFB1 by A. flavus in culture medium and on pistachios infected with the fungus.

Neem seeds were collected from Bandar Abbas in Hormozgan province from August to October 2016. Consecutive ethyl acetate, water, and hexane methods were used to extract Azadirachtin from neem seeds. After drying, the powdered extract was formulated with Tween 20 and sunflower oil. To evaluate aflatoxin production, Potato dextrose broth (PDB) culture medium containing A. flavus (6 log CFU / ml) and 0.3 ml extract were prepared and placed in an incubator for 9 days.

The results showed that the amount of fungal mycelium increased in the presence of ethyl acetate extract from neem seed, but the amount of aflatoxin B1 of this fungus decreased around 17% compared to the control sample (free of the formulated extract using the formulation of 1% of this extract).

The effectiveness of the formulated extract is attributed to tetranortriterpenoid such as Azadirachtin A. The use of the obtained formulation showed that in addition to the previous properties reported about neem seed extract, which prevents the plants from Insect damage, it can reduce the damage caused by aflatoxin contamination in pistachio. The 1%formulated of this neem extract had no effect on fungal growth, but the most important difference between studies on neem extract and Azadirachtin extracted in this study is the reduction of aflatoxin production by fungi. In other studies, aqueous extract of neem producing aflatoxin was reduced significantly, while Azadirachtin purified in this study had little effect on reducing aflatoxins.

Iranian Pistachio is one of the most important horticultural product in export market. Crown and root rot caused by Phytophthora species is the most serious disease of plant, which annually destroys a considerable number of mature and young trees. This disease has been reported from all provinces of Iran. The pathogen is soil-borne and is distributed by sporangia or the released zoospores and infects the healthy trees. In the most Pistachio orchards, the key factors of disease development are the sensitivity of pistachio crown to Phytophthora and the flooding method of irrigation. The symptoms of the disease are include blight in early spring, drying of the green leaves during the growing season, gum exudation from the crown of tree  and the root rot. Gummosis can be successfully controlled by integrated disease management including orchard constructing in non-infected areas, using resistant or tolerant cultivars, using healthy rootstocks, improving the irrigation methods and avoiding the direct contact of water with tree crown, isolating the contaminated parts of the orchard from the healthy parts, using suitable fungicide, and biological control based on Trichoderma and Bacillus species.

Aflatoxin B1 (AFB1) is a mutagenic and carcinogenic compound mainly produced by the Aspergillus parasiticus, A. flavus, A. nomius, A. tamari, and A. pseudotamarii. AFB1 biodegradation is the most important strategy for reducing AFB1 in plant tissues. Bacteria can deactivate and biodegrade AFB1 for effective detoxification of contaminated products. The present study investigated the efficiency of AFB1 degradation by soil bacteria from the Southern Khorasan Province in Eastern Iran by thin-layer and high-performance liquid chromatography during 2014–2015.
DNA was extracted from AFB1-degrading isolates by the cetyltrimethylammonium bromide method and the 16S rRNA gene was amplified with the 27f and 1492r general bacterial primers and the sequences were used to identify the isolates based on their similarity to Gene Bank sequences of known bacterial species.
We isolated five strains from four species of AFB1-degrading bacteria from Birjand plain, including Bacillus pumilus, two isolates of Ochrobactrum pseudogrigonens, Pseudomonas aeruginosa, and Enterobacter cloace, which had AFB1-degrading activities of 88%, 78%, 61%, 58%, and 51%, respectively.
We provide the first demonstration of AFB1 degradation by B. pumilus in from Iran and the first report identifying O. pseudogrigonens and E. cloace species as having AFB1-degrading activity.

Boxwood tree is one of the Iranian endemic trees expanded throughout Hyrcanian forests. They are of particular importance among the world's forest reserves. Recently, Calonectria pseudonaviculata has been considered as one of the most important causes of blight and leaf defoliation of the boxwood in Iran. For the first time, the present study was aimed to evaluate the genetic variation of Hyrcanian C. pseudonaviculata isolates using RAPD and ISSR markers.
Material & In this study, 75 fungal isolates were collected from the infected boxwoods throughout Hyrcanian forests in the North of Iran. The isolates were assessed based on morphology and colony color. Genetic diversity of the isolates was studied using RAPD and ISSR markers. A part of the beta-tubulin gene was sequenced and deposited at NCBI. Phylogenetic analysis was carried out using PAUP* v. 4.0b10.
The colony color of isolates on potato dextrose agar (PDA) medium was brown with pale hale, conidia were cylindrical, rounded at both ends, 1-septate, 48- 68 µm. Stipe was long (90-14 µm) and hyaline, with the extension terminating in a broadly ellipsoid papillate vesicle, the widest part above the middle. Phylogenetic tree based on the β-tubulin gene showed that all isolates are placed into the same group. Our results indicated that the population of this fungus has a low genetic diversity in Iran.
It seems that the variation of this pathogen is started to change genetically in some areas due to selection pressure phenomenon.

Thirty-seven isolates of Fusarium graminearum species complex obtained from wheat heads with Fusarium head blight symptoms were selected and used for phylogenetic studies. They were collected from different localities of Moghan plain (Ardebil province, Iran). Partial sequences of translation elongation factor 1-alpha (TEF), putative reductase (RED) and UTP-ammonia ligase (URA) genes were amplified using specific primers and sequences were analyzed using Maximum Parsimony method. Almost all strains of F. graminearum species complex belonged to F. graminearum sensu stricto. The results indicated homogeneity within F. graminearum species complex. Inter-simple sequence repeat markers (ISSR) were employed to study the genetic structure of F. graminearum s.s. populations collected from five localities in Moghan plain. The ISSR markers were generated by five primers and data analysed using UPGMA method with Jaccard's coefficient. Cluster analysis showed that all isolates were divided into four clades with 82 similarity level. The analysis of molecular variation indicated that most of the gene diversity (97%) was distributed within populations, whereas 3% of the variation was found among populations. Phylogenetic species identification and genetic diversity knowledge of major agent of FHB disease will be useful in defining the risk of pathogen evolution as well as benefiting disease management strategies.

In order to determine the causal agents of Fusarium head blight, during 2015–16, wheat heads with disease symptom were collected from 10 and six main wheat production areas of Golestan and Mazandaran provinces (N Iran), respectively. A total of 431 Fusarium isolates were obtained belonging to nine Fusarium species based on their morphological characteristics. Fusarium graminearum species complex had the highest frequency among the species in both provinces, Golestan (52.0%) and Mazandaran (55.8%). Fusarium culmorum, F. equiseti, F. Acuminatum, and F. compactum had the highest mean of frequency in both provinces with 13.5, 9.7, 6.0 and 3.7%, respectively after F. graminearum. Also, F. cerealis, F. Avenaceum, and F. proliferatum and some unidentified isolates a total of 14% of the isolates were calculated. The lowest frequency was related to F. subglutinans (1%) that was isolated only from Golestan province. In order to determine the phylogeny of F. graminearum species complex in the North Iran, 53 out of 229 isolates were selected based on their distribution in the sampled areas. Partial genes of translation elongation factor 1-alpha (TEF) and putative reductase (RED) were amplified using specific primers. A commercial sequencing facility was used to generate fungal sequences. Almost all strains of F. graminearum species complex belonged to F. graminearum sensu stricto. The results indicated a homogeniety within F. graminearum species complex, however, there was a minor morphologically differences between some strains.

Pistachio is the most important commercial product in Iran and root and crown rot (gummosis) is the most serious diseases of this crop. Causal agents of the disease were unknown in Sistan -va- Baluchistan province where 7000 ha are under cultivation of pistachio. During 2 years, thirty pistachio orchards including pistachio trees of different ages were inspected throughout different seasons. Eight Phytophthora isolates were isolated using citrus leaves pieces as baits on water-saturated soils collected from around the infected trees and cultured on PARP medium. Some isolates were isolated culturing the surface disinfected tissues of root and crown of infected trees directly on PARP as the semi-selective medium too. Two groups of isolates were obtained. Based on the morphological and physiological characteristics of the Sistan -va- Bluchistan pistachio isolates, the first group of isolates was identified as Phytophthora pistaciae and the second group identified as Phytophthora nicotianae. The two Phytophthora species were found pathogens using unripe pear and apple fruit inoculation method, detached pistachio twigs inoculation method and artificial inoculation of the crown area with a plug of cultured isolate medium. This is the first report of incidence of pistachio tree gummosis and its causal agents from Sistan -va- Baluchistan province.

Soybean, Glycine max (L.) Merr is one of the most important oilseed plants in the world and Phythophthora root and crown rot is a significant limiting factor for its planting. In the present study the antagonistic effect of 12 Trichoderma spp. in vitro and these Trichoderma spp. in combination with Bradyrhizobium japonicum in vivo on Phytophthora sojae and soybean growth were tested. In laboratory tests the effects of Trichoderma isolates were studied in dual culture, volatile compounds and culture filtrate metabolites. The most hyphal growth inhibitions were obtained using T. virens, T. orientals and T. brevicompactum in dual culture tests and T. atroviride in volatile compounds test. The effects of Trichoderma culture filtrates on P. sojae hyphal growth were studied at six concentrations in CMA medium and the results showed that culture filtrates of all species inhibited the hyphal growth and that different concentrations had different inhibitory effects. The most inhibition was obtained by T. virens and T. brevicampactom culture filtrates. The greenhouse tests were carried out as two experiments. In the first experiment the effects of coated seeds with Trichoderma isolates and B. japonicum, alone and in combinations, on control of P. sojae and in the second experiment the effect of these two biocontrol agents on soybean growth, alone and in combinations, were assayed. In the first experiment, germination percentage, damping-off, seedling vigour index (SVI) and disease severity were measured and results showed that T. brevicompactum as alone and in combinations, was the most effective species. In the second experiment, coated seeds with Trichoderma isolates and B. japonicum, as alone and in combinations, significantly promoted the growth of treated seeds and the most effective species were T. orientals, T. brevicompactum and T. spirale. Hence, results indicate that T. brevicompactum, as the second most common species after T. harzianum in Iran, was the most successful species applied individually and in combinations with B. japonicum to act as biocontrol agent for P. sojae and was also able to promote plant growth.