Many fungi cause sugar beet root rot during various stages of the plant growth. Among them Rhizoctonia spp. induce crown rot, dry rot and violet root rot on sugar beet (Whitney and Duffos,1986). Root rot caused by Phytophthora drechsleri has been observed in fields with excessive moisture (Habibi,1975). Pythium aphanidermatum has been recognized as one of the causal agents of sugar beet, damping-off, root rot and seed deterioration (Ahmadinejad and Okhovat, 1976). Rhizopus arrhizus has been also reported as one of the fungi involved in crown rot of sugar beet (Habibi,1977). In order to determine pathogenic fungi involved in sugar beet root rot and their distribution in Kermanshah province, this investigation was carried out during 1998-1999. Forty-one fields in different parts of the province were surveyed. At every field some information about previous crop in rotation, method of irrigation, source of irrigation water and disease severity was recorded. From each field, 2-5 root samples showing root rot symptoms were collected and transferred to laboratory. A soil sample was also collected and analyzed in the laboratory. Ninty eight isolates belong to Fusarium spp., Rhizoctonia solani, Binucleate Rhizoctonia, Phytophthora drechsleri, Pythium aphanidermatum, Rhizopus arrhizus, Rhizopus stolonifer, Macrophomina phaseolina, Phoma betae, Mucor spp. and Geotrichum sp. were isolated. In this study, although the majority of the isolates belonged to Fusarium spp., they could not induce root rot symptoms in pathogenicity tests. The most severe symptoms of root rot were induced by R. solani, P. drechsleri, P. aphanidermatum and R. arrhizus. Among soil specifications, only soil saturation percent had a weak relationship with disease severity and other factors showed no distinct relation with disease symptoms. Figure 1 shows distribution of the fungi involved in sugar beet root rot in Kermanshah province.

During 2009 and 2010 growing seasons, different irrigated fields were surveyed in Gorgan region. Infected plants with symptoms such as damping off, crown and root rot, and foliar blight were collected. Samples were washed in running tap water and cultured on CMA+PARPH. Isolates were identified on the basis of morphological and some physiological characteristics.50 isolates belonging to four species were identified. The species were: Phytophthora citrophthora from persimmon fruits (Diospyros kaki); Phytophthora cryptogea from kiwi trees (Actinidia chinensis) with root and crown rot sympotoms, crown and root of potato (Solanum tuberosum) and gerbera (Gerbera jamesonii), Phytophthora nicotoanae from tomato (Lycopersicum esculentum) root and stem, Phytophthora palmivora from root and crown of olive (Olea europae) seedlings and Phytophthora inundata from root and stem of broad bean (Vicia faba). All of Phytophthora isolates were found pathogen on their host at greenhouse conditions. Based on our knowledge isolation of P. cryptogea group II from kiwi and potato and Phytophthora palmivora from olive trees were new for Iran, also P. inundata from broad bean was new for Iran and the world.

Legumes are one of the primary protein sources in human and livestock diets worldwide. There are five different types of legumes (i.e., beans, peas, peanuts, lentils, and lupines), with beans as the most important. Fusarium root rot (FRR) is among the most challenging diseases of common beans (Phaseolus vulgaris). While soil-borne diseases are difficult to control, resistant bean cultivars significantly help reduce the losses caused by the disease. This study was conducted in a greenhouse to investigate the susceptibility of different bean cultivars to FRR caused by the F. solani species complex (FSSC).

Several bean fields in Fars, Kohgilouyeh and Boyer-Ahmad, Chaharmahaal and Bakhtiari, Hamdan, Lorestan, Markazi, Qazvin, Zanjan, East Azerbaijan, and Mazandaran provinces were explored during summer from 2017 to 2019. Infected plants were sampled, and the fungi were isolated in the laboratory. Once appeared on the culture medium, the fungal isolates were purified using single-spore isolation or hyphal tip methods. Fungal DNA extraction was performed using Doyle and Doyle’s method for molecular identification of the isolates. A part of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene and a translation elongation factor 1-alpha (EF-1α) were amplified from the polymerase chain reaction (PCR). PCR-amplified fragments were sent to the Cardiogenetics Department of Rajaie Cardiovascular, Medical and Research Center (Tehran, Iran) for sequence analysis. After editing, the Basic Local Alignment Search Tool (BLAST) was applied to ITS and EF-1α sequences of the isolates in the GenBank data set in the National Center for Biotechnology Information (NCBI) database. A preliminary pathogenicity test was performed on the Sadri bean cultivar-pathogenicity tests were fulfilled in 400ml plastic pots. An inoculum was prepared by pooling the isolates in a pot experiment utilizing Bilgi et al.’s (2008) method to evaluate bean cultivars. Ten representative isolates of F. solani with the highest pathogenicity were selected from different regions. The cultivar susceptibility was assessed in 3-liter pots as described in the preliminary pathogenicity test. Saleh, Sadri and Koosha chiti (pinto) bean cultivars, Akhtar, Goli and Sayyad red bean cultivars, Dorsa, Shekoofa white bean cultivars, and Valentino and Sanri green bean cultivars were compared based on disease severity and yield correlates (shoot/root fresh and dry weight).

Fusarium isolates from the sampled provinces were identified using authentic scientific sources and Fusarium identification keys based on morphological properties. A Blast search of ITS and EF-1α sequences in GenBank yielded 100% nucleotide identity with the sequences of strains of FSSC. In the preliminary pathogenicity test, leaf yellowing and falling symptoms appeared on the Sadri cultivar in the greenhouse three weeks after inoculation. All FSSC isolates caused root rot on the tested bean cultivar. To evaluate the susceptibility of bean cultivars to the selected isolates, the plants were carefully removed from the 3-liter pots two months after inoculation. The results showed statistically significant differences (p=0.01) among the cultivars. Koosha chiti bean, green Sanri and Valentino cultivars with the lowest root rot severity (19.5%, 22.62% and 23.81%, respectively) and red Goli and Dorsa white bean cultivars with the highest root rot severity (66.67% and 70.24%, respectively) were the least and most susceptible bean cultivars to the pooled FSSC isolates, respectively. The results also indicated relatively significant differences in yield correlates (shoot/root fresh and dry weight) among the cultivars. Besides, the Koosha cultivar was shown to be the most resistant to the disease, followed by Akhtar, Sanri, Valentino and Saleh cultivars. Dorsa white bean and Goli red bean cultivars were demonstrated to be the most susceptible to the disease. This study identified several cultivars with low susceptibility to bean root rot caused by FSSC isolates. A good variation was observed in the spectrum of bean plant responses to the disease. Koosha, Akhtar, Valentino, Sanri and Saleh cultivars with low susceptibility to the selected FSSC isolates may be considered for further studies. Proper soil management with cultivating resistant cultivars is an integral part of any disease management program for FRR.

In this study, the antagonistic activities of eleven isolates belonging to 10 species of Trichoderma fungi including Trichoderma harzianum, T. atroviride (two isolates), T. viride, T. orientalis, T. citrinoviride, T. asperellum, T. spirale, T. crassum, T. pseudokoningi and T. ceramicum against rhizoctonia solani AG2-2, the causal agent of sugar beet root rot, were evaluated in a completely randomized design with four replications. Results showed that all Trichoderma isolates reduced the growth of pathogen significantly and the highest antagonistic effects were observed in dual culturing test in T. harzianum Z1 isolate, which caused 76.57% inhibition of pathogen mycelial growth. In greenhouse experiments, the efficacy of four selected Trichoderma isolates on sugar beet root rot control in Shirin cultivar was evaluated. Results showed that T. harzianum Z1, T. atroviride Z2, and T. orientalis Z4 caused 71.1, 66.6, and 58.3% decrease in root rot severity, respectively. In field experiments (2013-14) conducted in Hamedan Agricultural and Natural Resources Research Center, the effect of selected Trichoderma isolates in comparison with fungal treatment (carboxin-thiram) and control treatment on the occurrence and severity of root rot was evaluated through artificial contamination by Rhizoctonia solani. Results showed that selected Trichoderma isolates were significantly different in terms of disease control and T. harzianum Z1 isolate caused 66.4% reduction in the incidence of infection and 56% reduction in root rot severity compared with control. Therefore, this isolate is considered as the most effective antagonist in decreasing of Rhizoctonia root rot disease of sugar beet root.

During 2001-2005, 79 isolates of Rhizoctonia from seed rot, seedling damping –off, root rot and dry rot canker of sugar beet were collected. Based on morphological characteristics, number of nuclei per cell and hyphal diameter, isolates were classified in two groups, binucleate (4 isolates) and multinucleate (75 isolates). Among 75 multinucleate isolates, 27 isolates were identified as AG4, 28 isolates as AG2, two isolates as AG3 and one isolate as AG5.The remaining of the isolates(17 isolates) did not anastomose with any of tester cultures. Most of isolates of AG2 had been isolated from root rot symptoms, but AG4 isolates from damping –off and root rot symptoms. From dry rot canker symptoms with concentric ring on the root surface of sugar beet, 5 Rhizoctonia isolates were collected, that did not anastomose with any tester cultures. Optimum temperature for mycelial growth ranged from 25 to 30, but for dry rot canker isolates was above 30 °C. Pathogenicity test was carried out in in vitro condition. Representative isolates from each AG and each geographic location were selected for pathogenicity test. Results showed that the isolates varied in their virulence.AG4 isolates were highly virulent on seedling and more virulent than AG2 isolates.AG3 and AG5 isolates caused superficial discoloration on seedling. From binucleate isolates, two of them were as pathogenic as dry rot canker isolates. Virulence variation of selected isolates of different anastomosis groups were also investigated on mature sugar beet plants under greenhouse conditions. Results showed that both isolates of anastomosis groups 2 and 4 had the ability to cause root rot, however, the disease severity of anastomosis group 2 (AG-2) on mature plants was higher than those of AG-4 group.

Fusarium is a significant soil fungus found globally. The fungus responsible for the disease can survive as chlamydospores in infected seeds and plant debris for more than five years in the soil. When conditions are right, it can devastate entire crops. This fungus releases spores that grow when they come into contact with chemicals from the chickpea roots. The fungal threads invade the plant's roots and vascular system, which blocks the plant's ability to absorb water. As a result, the chickpea plant can die from lack of moisture. In Iran, the disease is common in many areas where chickpeas are grown, resulting in a 17% decrease in chickpea yields. In Lorestan Province, it causes root rot and wilting in chickpeas, severely impacting their production. Under suitable conditions, this disease can entirely devastate crops. To effectively manage this issue, it is crucial to identify the various Fusarium species, understand their detrimental effects, and evaluate which plants they can infect. Also, studying these species' genetic relationships can facilitate the development of improved disease control strategies.

This study focused on identifying Fusarium species that cause root rot in chickpeas in Lorestan Province. Researchers visited chickpea farms, collecting 155 samples from plants exhibiting yellowing, wilting, and root rot symptoms. The samples underwent isolation, purification, and identification in the laboratory based on their morphological traits. Pathogenicity tests were conducted on a susceptible chickpea cultivar named Arman to evaluate the pathogenic potential of the identified Fusarium species. This study focused on analyzing specific genetic markers to identify particular isolates. Researchers amplified two gene regions: the internal transcribed spacer (ITS) of ribosomal DNA and the ef1-α gene, utilizing materials from SinaGen Company. The amplified DNA fragments were sequenced by Biomegic Company in Tehran. The sequences were edited and analyzed using BioEdit 7.1 software and registered in the NCBI GenBank database. MEGA 7.0 software was employed for phylogenetic analysis to construct a phylogenetic tree, comparing the isolates with others in the gene bank. A bootstrap analysis with 1,000 repetitions was conducted to confirm the stability of the phylogenetic tree branches. The study evaluated specific isolates' harmful effects on the above-ground parts and roots of intentionally infected plants.

The phylogenetic tree presented in this study, constructed from specific gene sequences, aligns with the results of morphological analyses. The research identified Fusarium oxysporum and Fusarium solani as the most prevalent isolates. F. falciforme affects plants by causing yellowing and wilting, starting from the lower leaflets and spreading upwards. The roots also show signs of damage, with visible root rot symptoms after emerging from the soil. Additionally, there are instances of discoloration in the vascular bundles when looking at sections of the stem, both longitudinally and cross-sectionally. These findings correspond with previous studies in the field. Furthermore, the study uncovered that Fusarium falciforme is a weak pathogen for chickpea roots. Importantly, this research represents the first documented evidence of the pathogenic effects of Fusarium falciforme on chickpeas.

The phylogenetic tree presented in this study, constructed from specific gene sequences, aligns with the findings of morphological analyses. The research identified Fusarium oxysporum and Fusarium solani as the most prevalent isolates. The disease symptoms linked to most isolates from the F. oxysporum complex in this study resemble those caused by F. redolens. DNA sequencing revealed that the F. oxysporum isolates are closely related to F. redolens, with a 96% genetic similarity. All isolates of F. redolens showed symptoms similar to those of F. oxysporum f. sp. ciceris in pathogenicity tests but without any color change in the vascular tissue. Since black root rot is a localized issue, it is crucial to differentiate it from systemic diseases like wilting for effective plant pathology understanding. A combination of molecular analysis and thorough morphological examination is essential to identify these isolates correctly. These results are consistent with previous studies on the subject. Furthermore, the investigation revealed that Fusarium falciforme exhibits weak pathogenicity towards chickpea roots. Importantly, this research represents the first documentation of the pathogenic effects of Fusarium falciforme on chickpeas.

Root and crown rot is a common tomato disease in the major production areas of Hormozgan province. The present study was conducted to isolate, identify, and determine the frequency of fungal agents associated with tomato root and crown rot in Hormozgan province. In total, 984 fungal isolates were obtained from tomato plants with yellowing, wilting, and root and crown rot symptoms. Identification of the isolates was done based on the morphological characteristics and the comparison of the obtained sequences of the ribosomal internal transcribed spacer region (ITS-rDNA) and parts of the translation elongation factor-1 alpha (tef1-α) gene with relevant sequences available in GenBank. According to the results, the highest frequency belonged to Fusarium oxysporum isolates (73%), and afterward to Rhizoctonia solani and F. acutatum species with eight and one percent frequencies, respectively. The results of the pathogenicity tests of the fungal species on tomato seedlings hybrid Sunseed 6189 at the stage of four true-leaves revealed that all three species were pathogenic on tomato seedlings and caused root and crown rot, yellowing, and death of the plant aerial tissues. Pathogenic isolates of F. oxysporum were identified as F. oxysporum f. sp. radicis-lycopersici using sprl-specific primers. To the best of our knowledge, this is the first report of F. oxysporum f. sp. radicis-lycopersici on tomato in Hormozgan province, and the first report of F. acutatum as tomato root and crown rot agent in the world.

Root rot is one of the important diseases of bean in Zanjan province and two fungal pathogens، Rhizoctonia solani and Fusarium solani are the major causal agents of this disease in the region. In this research، the inhibitory effect of N-hexane، di-ethyl-ether، chloroform and ethanol extracts of five plant species، hermel (Peganum harmala)، thyme (Thymus kotschyanus)، yarrow (Achillea wilhelmsii)، pennyroyal (Mentha pulegium) and garlic (Allium sativum) on mycelial growth of R. solani and F. solani was studied using poisoned food technique at four levels of 100، 250، 500 and 1000 ppm with three replications. After laboratory experiments، the most effective extracts، were applied against bean root rot under green house conditions. According to the results from in vitro studies، N- hexane extract of thyme and pennyroyal (both at the level of 1000 ppm) had the most inhibitory effect against both pathogens and also caused cytoplasm granulation and leakage of intracellular compounds of hypha of both fungi. At greenhouse experiments، hexane extract of thyme and menthe not only significantly reduced the root rot percentage، but also had significant increasing effect on most plant growth parameters (P = 0. 05).

Fusarium rot is one of the most important diseases of beans (Phaseolus vulgaris). In order to identify Fusaria that cause bean root rot in Markazi Province (Iran), in the summer of 2018 and 2019, several bean fields were visited and infected plants with root rot were sampled and the fungi were isolated in the laboratory. Based on morphological and sequencing characteristics of internal transcribed spacers of rDNA (ITS) and translation elongation factor 1-α (EF-1α) gene regions, 37 Fusarium isolates, including Fusarium oxysporum species complex, F. solani species complex, and F. lateritium species complex, as well as F. equiseti, F. acuminatum and F. redolens were identified. All isolates caused root rot on Sadry bean cultivar. Since F. solani isolates were the most common, twelve isolates of this group were selected and their phylogenetic relationships were studied. Of the three Clades of F. solani species complex, the isolates were placed in Clade 2 and 3. Only one isolate was found in Clade 2 whose properties matched those of F. brasiliense. The other isolates were classified in Clade 3 divided into two subgroups. In host range tests of F. solani isolates, none of the isolates was pathogenic on lentils, vetch and cowpea. A number of isolates caused root rot in chickpeas, soybeans, and potato tubers. F. lateritium, F. redolens and F. brasiliense are reported for the first time from Iran.

To study the effect of planting date on root rot disease caused by Fusarium solani f.sp. phaseoli of Chitti bean (Phaseolus vulgaris L.), an experiment was conducted in Khomein Bean Research field Station in 2004 and 2006 cropping seasons. This experiment was arranged as split plot in a randomized complete block design with three replications. Three chitti bean genotypes (local Khomein, Talash, and COS16) were sown in four different planting dates (10 May, 25 May, 09 June, and 24 June). Combined analysis of variance showed that the effect of planting date on seed/pod, seed/plant, 100 grains weight, seed yield and root rot disease severity was significant at the 1% probability level and on pods/plant at the 5% probability level. Effect of cultivar on pods/plant, grains/plant, 100 grains weight and root rot disease severity was significant at the 1% probability level and on grains/pod and grain yield at the 5% probability level. Planting in 09 June and COS16 genotype produced the highest seed yield. Delaying planting date decreased disease severity. COS16 and local Khomein genotypes had the least and the highest disease severity, respectively.