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Corn (Zea mays) is from the cereal category and the large wheat family; it is the third crop after wheat and rice cultivated areas worldwide. This research aims to investigate the detection and identification of the pathogenic bacterium Pantoea dispersa in Iran using biochemical and molecular identification methods and the host range of this bacterial species. For this purpose, in two consecutive years, sampling was done from the corn fields of different provinces of Iran, which have symptoms such as leaf spots and wilting. Standard plant bacteriology methods were used to isolate bacteria with the mentioned symptoms, and isolates were identified using biochemical characteristics and primers related to housekeeping genes. In the investigation of pathogenicity and host range of 20 bacterial isolates obtained from different corn fields, six isolates were identified as P. dispersa. This is the first report of the presence of the bacterium in Iran. In examining the host range of the mentioned isolates millet and sourghum are introduced as new hosts of this species in Iran. [ABSTRACT FROM AUTHOR]

Alfalfa is an important agricultural crop and the most important forage crop in Iran, playing a crucial role in providing feed for livestock. Hephomycetous fungi are considered as part of the factors associated with the leaf spot disease of alfalfa. In this study, according to the importance of alfalfa cultivation in West Azerbaijan province, in November 2020, samples of alfalfa plants with leaf spot symptoms were collected from various farms in the southern regions of this province, including Miandoab, Mahabad and Naghadeh. After direct examination and single-spore isolations from the leaf spots, 66 fungal isolates from different fungal genera were obtained. After growing the isolated fungi on standard culture media and primary morphological identification, molecular analysis of representative isolates was performed using the ITS ribosomal region and or parts of the gapdh gene. Based on morphological and molecular characteristics, eight species belonging to five genera of hyphomycetes including Albifimbria verrucaria, Alternaria atra, Alternaria kordkuyana, Alternari sp. (section Alternaria), Cercospora zebrina, Curvularia inaequalis, Stemphylium botryosum and Stemphilium vesicarium were identified. Following pathogenicity test under greenhouse condition, the pathogenicity of Alb. verrucaria, A. kordkuyana, C. zebrina, S. botryosum and S. vesicarium species was confirmed. Among the identified species, A. atra, A. kordkuyana and Cu. inaequalis are first world records on alfalfa. [ABSTRACT FROM AUTHOR]

During the visit of some banana cultivation areas in 2021 and 2022, sampling of leaves and roots with symptoms of leaf spot and wilting was done in Sistan and Baluchistan, and Hormozgan provinces. After being transferred to the laboratory, twenty-eight isolates belonging to the genus Fusarium sensu lato were isolated from the infected samples.. The isolates were identified by carnation leaf agar and SNA under 12 hours of near UV light and 12 hours of darkness. The results of the morphological investigation and phylogenetic analysis based on Elongation factor 1-α (EF 1-α) gene region showed that isolates belonged to Fusarium oxysporum (12 isolates), Fusarium incarnatum (10 isolates), Neocosmospora sp. (7 isolates), and two unknown isolates of Fusarium. The pathogenicity test was conducted to compare the pathogenicity of the species on the Dwarf Cavendish banana variety. Pathogenicity test results showed the isolates could cause leaf spot (Fusarium sp. and Fusarium incarnatum) and wilting (Fusarium oxysporum, Fusarium incarnatum and Neocosmospora sp.) in banana plants under greenhouse conditions. Based on our knowledge, this is the first report of F. incarnatum and Neocosmospora sp. pathogenicity of banana in Iran. [ABSTRACT FROM AUTHOR]

The septoria leaf spot caused by Zymoseptoria tritici is one of the most destructive wheat diseases in the world, which causes lots of damage to this crop annually. The aim of this study was to investigate the effect of 0 and 200 ppm of chitosan on the expression of defense genes and antioxidant enzymes (peroxidase, catalase and ascorbate peroxidase) activity, in Koohdasht wheat cultivar (susceptible cultivar) in interaction with the pathogen. Therefore, two-week plants were sprayed with chitosan, and then treated plants along with control plants were inoculated with Z. tritici pathogen. Finally, the expression rate of PR1, PR2 and PR5 genes were examined using qRT-PCR technique at 0, 12, 24, 48, 96, and 240 hours after inoculation (hai). According to the results, disease severity reduced by about 55% in chitosan pre-treated plants compared to control. The results of qPCR showed that expression of mentioned genes increased in treated and control plants, but the expression of PR1, PR2 and PR5 genes increased by 7.5, 4.15 and 3.76 times more in treated plants compared to control in 24 hai, respectively. Comparing enzyme activity in chitosan pre-treated plants and control, indicates an increasing trend of peroxidase enzyme and a decreasing trend of catalase and ascorbate peroxidase in the first group of plants. The examined gene expression and antioxidants pattern changed in both groups of plants indicates the effectiveness of chitosan in inducing resistance against septoria leaf blotch in wheat. [ABSTRACT FROM AUTHOR]

Pyricularia oryzae is the cause of blast leaf spot disease on rice and more than 50 plant species of crops and weeds in Poaceae family. Sampling was performed in 2017 in rice fields of Guilan and Mazandaran provinces. Morphological studies showed that the isolates obtained from Oryza sativa, Setaria viridis, Echinochloa crus-galli, Sorghum halepense, and Paspalum dilatatum were belonged to P. oryzae. The pathogenicity test revealed that isolates obtained from each host had higher pathogenicity on the same host and were either not pathogenic or less pathogenic on other hosts. Cluster analysis of DNA fingerprinting data using rep-PCR showed that isolates obtained from different hosts were located in three lineages. In general, there were isolates from different hosts in two identified lineages (except lineage C), and no correlation was found between the similarities of the band pattern with their collection areas. [ABSTRACT FROM AUTHOR]

Soybean, sesame and rapeseed are important industrial crop plants in the world and Iran. Cercospora leaf spot is a significant threat to the production of these crops particularly in soybean, worldwide. In a field survey in Golestan and Mazandaran provinces, the widespread distribution of Cercospora leaf spot symptoms on soybean, sesame and rapeseed was observed. In order to identify the fungal agents associated with this disease, symptomatic leaves were collected from the field and taken to the laboratory. Single spore cultures derived directly from leaf spots. In total, 50 isolates were obtained of which eight isolates from soybean, four isolates from sesame and four isolates from rapeseed were identified based on sequences of six genomic loci (ITS, act, tef1, cmdA, his3 and gapdh), host plant, and morphological data. The results of phylogenetic analysis have revealed that Cercospora cf. sigesbeckiae is a causal agent of cercospora leaf spot of soybean, sesame and rapeseed in Golestan and Mazandaran provinces. To our knowledge, this is the first report of Cercospora cf. sigesbeckiae for Iran mycobiota and its first report on sesame and rapeseed in the world. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the image processing technique in rice blast disease detection in field and controlled conditions. Using MATLAB software, images taken from field and controlled conditions were processed in three RGB, HSI and LAB color spaces. Then it was extracted by the gray area intensity profile, color properties, and threshold value for background image removal. After removing background in RGB, HSI and LAB color spaces, disease spots on rice leaf were determined. In RGB color space, by subtracting arrays by test and error, the blast patches on the leaf were separated from the rest of the image pixels. Hue was used in the HSI color space because this component was independent of light intensity variations, so blast blot identification was performed more accurately than the S and I components. In the LAB color space, the Kmeans clustering algorithm was used to segment the images into three clusters and was displayed in an independent cluster after labeling the image of blast disease spots. Finally, in order to determine the performance of the algorithms designed in three color spaces, the sensitivity factor, specificity and total accuracy were tested on the basis of the perturbation matrix for 500 image samples. In field and controlled conditions, the highest accuracy in detecting blast blots in the LAB color space was 94% and 98%, respectively. Overall, the results showed that the image processing method can be used to detect rice blast disease. [ABSTRACT FROM AUTHOR]

Melon (Cucumis melo) which belongs to the family Cucurbitaceae, is one of most important plants, cultivated in different regions of Iran. In a field survey in Guilan province, the widespread distribution of leaf spot symptoms on melon was observed. In order to identify the fungal agents associated with this disease, symptomatic leaves were collected from the field and taken to the laboratory. Single spore cultures derived directly from leaf spots. In total, 45 isolates were obtained of which 16 were identified based on sequences of five genomic loci (ITS, ACT, tef1, cmdA and his3), host plants, and morphological data. The results of fivegene phylogenetic analysis have revealed that, of the 16 isolates, four isolates were identified as Cercospora sp. G and the remaining 12 isolates nested within Cercospora cf. flagellaris. To our knowledge, this is the first report of the Cercospora sp. G and Cercospora cf. flagellaris on Cucumis melo in the world. Moreover, it is the first report of Cercospora leaf spot (CLS) on Cucumis melo in Iran. [ABSTRACT FROM AUTHOR]

Medicinal plants have undoubtedly been considered by human beings since ancient times. Sambucus ebulus (Caprifoliaceae) is one of the best known medicinal herbs since ancient times and is native to Southern and Central Europe, Northwest Africa, and Southwest Asia (especially Northern Iran) (Westwood 1985; Jabbari et al. 2017). It plays an important role in traditional medicine in many countries from different regions of the world (Jabbari et al. 2017). During the summer of 2014, leaf spots have been observed on S. ebulus plants in Gilan and Mazandaran provinces, Iran. Symptoms on infected leaves appeared as brown necrotic spots that surrounded by distinct dark brown haloes and were circular to irregularly in shape. During the summer of 2014 and 2015, sampling was done in Gilan and Mazandaran provinces from symptomatic leaves of S. ebulus and the fungus was isolated on 2% water agar (WA 2%) and potato dextrose agar (PDA). Pure fungal cultures were obtained by picking up a single spore on PDA. For morphological identification, the isolates were cultured on Potato Carrot Agar medium (PCA) and incubated at 25 °C under cool-white fluorescent with 16 h dark, 8 h light photoperiod for 14 days (Simmons 2007). The seven-days-old colonies on PCA were dark olive to brown in color and 70 mm in diameter. Primary conidiophores were often simple, reached to 70 μm in length and produced numerous conidia in a simple long chain. The conidia were 8–12 × 20–45 μm in size, egg or club shaped and contained 3-5 transverse and 1-2 longitudinal septa (Fig. 1a-c). According to macro- and micro morphological characters, all recovered isolated were identified as Alternaria tenuissima which was later synonymized under the name of A. alternata by Woudenberg et al. (2015). PCR amplification of the nuclear ITS-rDNA and RNA polymerase II second largest subunit regions was performed using primers ITS1/ITS4 and RPB2–5F2/fRPB2–7cR respectively (White et al. 1990, Sung et al. 2007; Liu et al. 1999). The sequence of NG1 isolate was deposited into the GenBank with the accession numbers MK212914 for ITS-rDNA and MK262741 for rpb2 region and living cultures of this strain were deposited in the Agriculture Biotechnology Research Institute of Iran culture collection (ABRII 10119). Phylogenetic estimates were evaluated using the Maximum Parsimony Analyses in MEGA 6.0 (Tamura et al. 2013). The results of phylogenetic study showed, NG1 isolate was clustered in a wellsupported clade (100%) including sec. Alternaria and related to Alternaria alternate isolates (Fig. 2). Pathogenicity test was performed in greenhouse condition on the detached leaves taken from healthy S. ebulus. Ten healthy leaves per isolates were cleaned with sterile water and were inoculated with conidial suspension containing 1 × 106 conidia/mL using the spray method. The control leaves were inoculated with distilled water. Leaf spots similar to the original symptoms were observed on all inoculated leaves after 5 days since inoculation and the fungus re-isolated from leaf lesions (Fig. 1e-g). Also, no symptoms were seen in controls. A. alternate is one of the important plant pathogen species with the worldwide distribution (Domesh et al. 2007) and has been reported as the causal agent of leaf spot disease on various hosts including Capsicum annuum, Solanum melongena, Solanum lycopersicum, Solanum tuberosum and Medicago sativa and various other hosts in the world (Li et al. 2011; Nasehi et al. 2012; Agamy et al. 2013; Zhao et al. 2016; Shahid et al. 2017; Abbasi et al. 2018). Additionally, there is a record of this fungus as the causal agent of leaf spot on Solanum tuberosum, Alo vera and Populus euphratica and Eriobotrya japonica in Iran (Ardestani et al. 2010; Abkhoo & Sabbagh 2014; Osdaghi et al. 2014). To our knowledge, this is the first report of A. alternata as the cause of leaf spots on Sambucus ebulus plant in the world. [ABSTRACT FROM AUTHOR]

Introduction: Common zinnia (Zinnia elegans), canna (Canna sp.), petunia (Petunia hybrida), compacta (Dracaena Compacta), dahlia (Dahlia sp.), gazania (Gazania sp.), marigold (Tagetes sp.), rose moss (Portulaca grandiflora) and nasturtium (Tropaeolum majus) are common ornamental plants in Ahwaz. The identification of fungi associated with these plants will contribute to improving the future management of their cultivation. Members of the genera Amesia and Chaetomium are widely distributed in soil, water, plants, animals and humans. In this study, 12 isolates from Chaetomium and Amesia genera, obtained from herbaceous ornamentals, were identified based on morphology and phylogenetic analysis. Materials and methods: During 2017-2018, 40 symptomatic plants, showing root rot, stem canker and leaf spot, were collected and their associated fungi were isolated. Among those, 12 chaetomiaceae-like isolates were obtained, which their morphological and molecular characterizations were surveyed. Mycelial biomass of the isolates, produced into potatodextrose- broth (PDB), was collected by passing through filter paper and freeze-dried. ITS and partial regions of the 28s-D1/D2 (for 4 isolates) and tub2 (for 9 isolates) were amplified using appropriate primers and sequenced. Results: The isolates under survey were compared with known strains using BLASTn search and phylogenetic analysis based on ITS, 28S and tub2 regions. Accordingly, the isolates under study were identified as follows: Amesia atrobrunnea, Chaetomium rectangulare, C. globosum, C. ascotrichoides and C. olivaceum. The morphological characteristics of these isolates were in accordance with the type strains of each species. Discussion and conclusion: To our knowledge, this is the first record of C. ascotrichoides in Iran and the association of C. rectangulare on compacta, C. globosum on zinnia and canna, C. ascotrichoides on petunia, C. olivaceum on common zinnia, nasturtium and marigold in the world. [ABSTRACT FROM AUTHOR]