mojdeh maleki

Molecular Fusarium wilt caused by Fusarium oxysporum. f. sp. melonis is one of the seed and soil-borne diseases of melons and cantaloupe. The epidemic of this disease can cause up to 100% destruction of melon and cantaloupe. The most damage usually appears after the emergence of flowers and the fruits formation, which causes yellowing, stopping growth, wilting and death of the plants. Chemical control methods or biological compounds have rarely been associated with success in reducing the disease. Therefore, the identification of isolates of this pathogen was investigated with the aim of identifying the level of pathogenicity and develop an efficient management plan. Infected plants from different areas of melon and cantaloupe cultivation in Varamin, Eyvanki and Garmsar cities was sampled and the pathogenic fungus was isolated. Pathogenicity was confirmed by immersing the roots of Samsuri Varamin (Niagara) seedlings in spore suspension. Investigating the pathogenic power and determining the identity of the isolates was done using differential numbers based on the five-level pattern. In this study, Taghan FO-VA-25 and Shah Sefid FO-SH-69 isolates from Varamin and Garmsar, respectively, with a disease severity index of 9.71 and 9.24, had the highest pathogenicity among the investigated isolates, and were identified under race 1.

The efficiency of powder microcapsules and suspension microcapsules of Talaromyces flavus with concentrations of 106 × 2, 106 × 4, 106 × 6, 106 × 8 and 107 colony forming units per gram of formulation in soil addition method and a concentration of 107 colony forming units per gram of formulation in seed impregnation method was compared with registered fungicide Talaromin in two methods of seed impregnation and addition to soil to control Fusarium wilt disease of tomatoes. The results showed that the most effective treatments were related to the different concentrations of suspension microcapsules by soil addition method and powder microcapsules by seed coating method and the highest concentration (107 colony forming units per gram) in adding to soil method reduced significantly 83- 96% the severity of the disease compared to the infected control.

Greenhouse cucumber is one of the most importance economic crops in Iran and many countries of the world. Many diseases threaten cucumber, and in other words, this product is always exposed to pathogenic organisms in its living environment, in which fungi and other plant pathogens cause many losses in vegetable and summer fields in Iran and around the world. Destructive diseases that cause significant damage to vegetable and summer crops in fields and greenhouses every year are seedling death disease and plant death disease caused by Phytophthora pseudofungus. The use of plant extracts and essential oils are of great value because so far no resistance to these types of compounds has been observed in pests and diseases, perhaps the reason for this is the presence of various effective compounds in these compounds and considering. The existing problems regarding the use of fungicides, study and research on new and reliable and low-cost methods for the control and management of plant diseases is a necessity for agriculture mangment in the world. In this study, the antifungal effects of denaei thyme essential oil (Zataria multiflora) & two fungicides fusetyl aluminum & metalaxyl-mancozeb were investigated to control the disease of greenhouse cucumber caused by Phytophthora.

In autumn and winter of 2018, sampling of cucumber greenhouses suspected of contamination was done in Garmsar city, Semnan province, Iran. The pathogenicity test of pseudofungal isolates was performed. Cucumber seeds were transferred to pots after germination and having two leaves. In the three- to four-leaf stage of the seedlings, the soil near the crown and roots was removed and the colony causing Phythophthora disease was placed next to the crown. In the control treatment, only pure culture medium without pseudofungi was used. Disease evaluation was done one month later. The test of mixing these three factors (thyme essential oil & two fungicides fosetil aluminum & metalaxyl-mancozeb) was used for laboratory tests. In this research, in addition to the effect of denaei thyme essential oil, fustil aluminum and metalaxyl-mancozeb were also used in five concentrations of 5, 15, 30, 45 and 60 ppm on Phytophthora pseudofungus. In order to determine the inhibition percentage of denaeithyme extract. Also,denaei thyme extract was evaluated in different concentrations including 250, 500, 1000, 1500 and 2000 ppm. In  greenhouse tests including pathogenicity test, evaluation of the mentioned treatments on the symptoms of the disease caused by Phytophthora sp. The activity of peroxidase, catalase & phenylalanine ammonialyase was also investigated. In tirst, the seeds of the cucumber plant after disinfection and cultivation in pots, in the stage of three to four leaves, according to the method of proving pathogenicity, respectively, the pathogen of Phytophthora sp. were inoculated (Gholamnezhad et al., 2016). After 24 hours, 50 ml of denaei thyme extract and the fungicides used in this research were added to the soil around the roots of the plants infected with the pathogen with a concentration of 1500 and 150 ppm, respectively.

The results showed that among the five fungal isolates studied in this study, isolates P1 & P5 caused more disease (78.52 & 62.68%, respectively). In the test of the effect of different treatments in preventing the growth of pathogenic fungal mycelium, a concentration of 60 ppm of metalaxyl-mancozeb fungicide with 96.32% had the highest effect in the control of the pathogen, but also concentration of 5 ppm of fossil aluminum with a rate of 12.30% had the lowest effect. . In present reserch metalaxyl-mancozeb fungicide 150 ppm by 88.60% inhibition of the pathogen and fusitel aluminum fungicide 150 ppm by 79.37% reduction of disease in the greenhouse were the best treatments during study. These results showed that to increase the effectiveness of this essential oil, it is necessary to use a higher concentration of essential oil compared to the chemical compounds studied in this study.

According to the results of this study, thyme essential oil has a high potential both in terms of antifungal power and induction of plant defense mechanisms against plant pathogens. However, the results of parametric analysis as well as analysis of variance showed that, compared to chemical compounds, higher concentrations of plant essential oils should be used to combat this disease.

Acquired systemic resistance (SAR) is one of the defenses that can make plants resistant to systemic viral infections. Acquired systemic resistance is associated with a hypersensitivity response in the host, and salicylic acid is known as its signal. In this study, the effect of plant inducers such as salicylic acid and jasmonic acid on cucumber viral disease with cucumber mosaic virus, CMV and the expression of some defense genes were investigated. Treatments included plants treated with CMV, salicylic acid (with a concentration of 1.5 mmol), jasmonic acid (with a concentration of 1.5 mmol), as well as salicylic acid and jasmonic with CMV. The results of this study showed that the maximum severity of CMV-induced disease was observed in plants treated only with CMV (68.85%). In the treatment of salicylic acid and jasmonic acid with CMV, the severity of symptoms was significantly reduced (10.23%). Then, the effect of these treatments on the expression of four genes Peroxidase (POX), Catalase (CAT), Superoxide Dismutase (SOD) and Phenylalanine Ammonialyase (PAL) was investigated. The results showed that the expression of these genes in treated plants had an upward trend until the ninth day after treatment. But this upward trend was much less observed in control plants (treated with water and virus). The highest level of gene expression in the studied enzymes compared to the control plant was related to the catalase enzyme (401.7 times), followed by peroxidase enzymes (266.8), superoxide dismutase (152.7) and phenylalanine ammonialyase (101.8). According to these results, salicylic acid and jasmonic acid, increased plant resistance to CMV and reduced the symptoms of the virus in cucumber plant by inducing plant defense mechanisms.

Pistachio is an important export product in Iran. This product is constantly threatened by Aspergillus flavus and its aflatoxin. Researchers are now looking to use alternative non-hazardous methods instead of other methods of management of plant diseases, such as the use of chemical pesticides. Plant extracts as an environmentally friendly method can be a good alternative to chemicals. In this study, the effect of plant extracts including lavender (Lavandula stoechas), thyme (Thymus vulgaris), fennel (Foeniculum vulgare) and savory (Satureja hortensis) on the amount of degradation and aflatoxin production in vitro, by paper disk methods and mixing the extract with the culture medium, as well as in the storage conditions and on pistachio were investigated. The results showed that using of 2000 mg/L methanol extract reduced the growth of pathogenic fungus by 65.63%. In the tests of using the extracts on the paper disc as well as mixing the extracts with the culture medium, aqueous extract of lavender with a concentration of 2000 μg/ml prevented the growth of pathogen by 39.31 and 55.96%, respectively, and thyme extract with a concentration of 2000 μg/ml inhibited the fungal growth by 29.33% and 39.54%, respectively. These extracts had the highest effect on the pathogen growth. When the extracts were applied directly to aflatoxin, the results showed that the concentration of 4000 mg/L lavender prevented the aflatoxin production in the culture medium by 91.18%. Finally, aqueous extract of lavender at 4000 mg/L showed the highest effect (76.95% compared to control) in reducing the amount of spores produced by pathogenic fungi on pistachio fruit. The results of aflatoxin content in pistachio showed that both studied plants (lavender and thyme) at concentrations of 2000 and 4000 mg/L significantly reduced the amount of aflatoxin produced. Due to the remarkable and good effect of plant extracts on pistachio fruit under both in vitro and in the storage, the studied extracts, especially lavender and thyme, are natural compounds with high fungicidal effect and environmentally friendly effects.

Charcoal rot on melon Macrophomina phaseolina is one of the most important soil borne diseases of melons. The disease has an economical importance throughout the world. So, infested samples from eight sampling points of Varamin Country (south-east of Tehran Province) and Garmsar and Eyvanekey Countries (Semnan Province) were collected, purified and admitted for pathogenicity on melon variety Samsouri. Then, pathogenicity of the sampled strains were compared using susceptible variety of melon, Samsouri. Totally, twelve strains of M. phaseolina were collected from the area with variable pathogenicity; although significant difference was observed among them. Strains MP-SH-34 and MP-SH-37 from Shah Sefid in Eyvanekey country had the highest pathogenicity ability and on the other hand, strain from Davarabad in Garmsar area showed the lowest pathogenicity; so, the strongest and infecting strain was MP-SH-34. According to the results, different strains of M. phaseolina is spread in melon farms of Tehran and Semnan Provinces which is needed to be managed.

Edible mushrooms are exposed to various diseases and pests that cause a serious reduction in yield. Dry bubble disease caused by Lecanicillium fungicola (Preuss) Zare and Gams is one of the most important diseases that causes damage to edible fungi. Due to the fact that a small number of fungicides are currently available to fight against fungal diseases, on the other hand, the overall resistance of Gia lavender fungi as an alternative to controlling oral fungal diseases. In this study, the effect of lavender essential oil was tested by two methods of mixing with culture medium and application of paper disc on the fungus causing dry bubble disease and edible fungus. In another part of the study, the effect of this essential oil on pathogenic fungi in storage and on edible mushrooms was investigated. The results of the essential oil mixing test with the culture medium showed that the essential oil of lavender in the concentration of 1000 ppm prevented the growth of pathogenic fungi by 89.25%. In the case of edible fungi, the highest inhibition of growth was related to the concentration of 1000 ppm essential oil of lavender and the control percentage was 65.23%. The results of the paper disk test showed that all the concentrations used in this study were able to reduce the growth rate of the pathogenic fungus. The highest inhibition rate was 1000 ppm and 83.12%. The results of the warehouse test showed that lavender essential oil increased the number of healthy fungi by 67.162% compared to the control by 7.30%. According to the results of laboratory and warehouse tests of lavender essential oil, they showed a high capacity to control diseases of edible fungi, especially dry bubbles.

Potato is one of the most important food and economic crops in all over the world, Rhizoctonia solani, the causal agent of stem canker causes high loss of the product quality and quantity annually. In this study, the effects of two essential oils of Thyme and Carum, were investigated on the colony growth rate and inhibitory growth in concentrations of 100, 200, 300, 400 and 500 ppm on PDA medium. In vitro tests, essential oils of thyme and Carum in two concentrations of 0.5 and 0.75, the combination of thyme 0.25+ Carum 0.25 and Rovral-Ts fungicide at 1.5 at 1000 were evaluated in a completely randomized block design in four replications. The tubers substratum cultivated in soil contaminated by R. solani that planted in pots were inoculated by essential oils and fungicides. The disease severity data were recorded and scored six weeks after inoculation using Das scale. The results demonstrated that fungal growth rate under treatment by Thyme at 500 ppm (21.63 mm /day) and Carum (17.7 mm/day) and thyme + Carum (67.85) essences were more than 50 percent growth inhibitory. The results of disease severity index in greenhouse revealed that Thyme and Carum essences and Rovral-Ts fungicide respectively by 28.1, 35.92 and 17.17 percent were successful in disease control as well as the mean of fresh and dry weight of shoot area under Thyme treatment increased relatively.

Tomato Fusarium wilt caused by Fusarium oxysporum fsp lycopersici is an important disease to tropical regions and sandy soils of Iran. In this study, the effect of essential oils of thyme, zynan, fennel and antagonist fungus of Tricoderma harzianum (Th-va-104) evaluated on the colony growth rate and growth inhibition in seven concentrations of 100-1000 ppm on PDA medium in vitro. The minimum percentage of inhibitory growth (Ec50) determined in essences of thyme, zynan and fennel with 83.95, 62/685, and 59.97% respectively. Tricoderma showed the maximum inhibition of fungal mycelial growth of F. oxysporum fsp lycopersici as 78.53% followed by thyme. The effect of thyme, Fennel and zynan essential oils at the concentration of 0.5 and 1, Fungicide (Iprodione+Carbendazim 52.5% WP) by concentrations of 1.5 and Tricoderma were evaluated in a completely randomized block design in greenhouse experiments. The essential oils were incorporated with potting soil with planting seedlings and Trichoderma fungus simultaneously in three days before transplanting. The percentage of disease severity index was assessed four weeks after inoculation. The results demonstrated that the disease index severity of thyme and Trichoderma by 2.6 and 2.06 respectively were placed in the closest disease index to check. The root area fresh and dry of thyme treatment (1.53, 2 gr), shoot area weight mean (13.19, 1.82) and the root area fresh and dry of Trichoderma (1.79, 0.27 gr) and shoot area weight mean (12.77, 1.63 gr), respectively were classified in the similar statistical groups with check.

Cucumber is one of the most important crops cultivated in greenhouses and field in Iran. Melon is one of members of Cucurbitaceae family and it has a large sweet fruit. Pseudomonas syringae is a bacterial plant pathogen that causes necrosis in aerial parts of the plants. As isolated P. syringae pv. lachrymans and P. viridiflava have been isolated from cucurbits in Iran and other bacteria not reported as pathogenic bacteria. Whereas agent of blister spot and leaf necrosis of cucumber andnot detected from Iran specially in Mazandaran. In this study, the cause of blisters and necrotic leaf spots cucumbers and melons after isolation from infected plants was identified by using morphological and molecular methods in Mazandaran. Based on the results of molecular tests and sequencing of the rpoB gene sequence, our bacterial agent was similar to about P. straminea, with 99 percent similarity. The results of this study showed the studied bacterium belongs to P. Straminea, and based on rpoB gene sequence closest species to it, was P. mendocina.

Cucumber (Cucumis sativus) is one of the important commercial products in Iran and the world rich in fiber and vitamin with high nutritional value. It is continuously attacked by soil-borne pathogens that are not only cause significant economic damage to crop yield, but also reduce quality and marketable of product. One of the most important and destructive soil-borne diseases of cucumber, damping off and root rot and crown caused by Phytophthora drechsleri Tuker. In this study, isolates of three species of biocontrol fungus Trichoderma were evaluated in laboratory and greenhouse conditions. The antagonistic isolates of three species were including Trichoderma harzianum (isolates Th3, Th5, Th6, Th7, Th9), T. longibrachiatum (isolate Tl2) and T. atroviride (isolates Ta1 ,Ta4, Ta8, Ta10) respectively. Dual culture tests were carried out in a completely randomized design with 11 treatments in three replications. Th6 Isolate, with 89.3% in dual culture showed the highest inhibitory effect on the. Hyphae twisting of different isolates of Trichoderma spp. were not observed in contact with Phytophthora but Trichoderma hyphae grown in parallel with Phytophthora hyphae and form Appresorium and Haustarium. Based on the results of this research, the most successful isolates for antagonist activity against P. drechsleri Tuker were Th6, Th5, Th3 and Ta1. These four isolates were selected for greenhouse studies. In greenhouse, tests of soil treatment and seed contaminated with the spore suspension of Trichoderma isolates for evaluating the biocontrol isolates in a completely randomized design with 10 treatments and three replications were conducted. Results showed that the isolates were able to control the disease in different levels. In seed treatment, Th6 and Ta1 isolates with 91.75 and 83.5 percent and afterwards, Th3 and Th5 isolates were more effective in reducing disease in first taking notes after soil treatment respectively. In seed treatment, Th6 and Ta1 isolates were more successful than other isolates and in inoculated treatments with the isolates and Phytophthora, seed germination percentage were recorded as 83.34 and 100 % respectively. In general, the seed treatment was more effective in reducing disease in comparison with soil treatment. Isolates were also effective in increasing plant growth and however, Ta1 and Th6 isolates significantly increased plant weight and height.

In this study the reaction of 27 tomato cultivars available in the country with isolates of Alternaria alternata f.sp. lycopersici collected from different regions were evaluated. For this purpose, to collect isolates from different regions and the pathogenicity of tomato varieties Pete Early-CH (susceptible to stem canker) was used. To identify the pathogen measurements were carried out in both macroscopic and microscopic. In this way, the color of the Colony and other macroscopic properties of the medium were examined under a microscope to examine the treatment of fungal spores and conidiophores and 100 were measured for each isolate was determined as the average. Other specifications, such as number of walls, length, width and color were investigated. A sample collected for testing of isolates susceptible cultivar was selected based on disease severity index. Selected varieties of seedlings after planting and transferred to pots in a greenhouse with suspension isolates of the fungus were inoculated in separate tests to measure disease incidence (Disease severity index) on the stem, after the elapse of the incubation period and the rise . Results of the evaluation showed that three varieties of stem canker Ps 550 and Xamen and Super Set in evaluating the area under the curve progression of the disease in stem cultivars, showed the lowest levels of development and were identified as resistant varieties. In order to study the fungus producing extracellular compounds and their role in the disorder, disease-causing bacteria in the PDB (infantry, dextrose liquid culture medium potatoes) Potato Dextrose Broth were killed. Tomato seedlings and leaflets for susceptibility to extracellular secretions (toxins) were evaluated. .

Bean anthracnose caused by Colletotrichum lindemuthianum (Sacc. and Magnus) Briosi and Cav., is one of the major diseases of common bean in relatively cool, wet cultivation areas of tropical and temperature regions. Crop losses can be severe or total, especially when susceptible cultivars are grown in a conductive environment for disease. In this study, first different fungal isolates were obtained from the west and north areas in Iran, purification and pathogenicity done on susceptible cultivar “Talash” with spore suspension with concentrations of 1-2 ×10 6 spores/ml on leaves in the greenhouse. Then the virulence of isolates conducted like pathogencity method on Talash cultivar. Disease severity index, 15 days after the spore spraying was rated using the method described by Van Schoonhoven and Pastor-Corrales. A total of 11 isolates C. lindemuthianum were obtained based on the results of sampling from different regions that had mostly high virulence, with different severity indices of the disease, ranging between 22.2 to 98. In reaction study of 40 bean cultivars or genotypes to causal agent in greenhouse conditions, six cultivars (Naaz, Pachebaghela- ragehghermez, Almas, Shekoofa, Daneshkadeh, Dorsa) and four genotypes (920040, 940040, 21676 and 31167) with infection degree less than 3 showed resistant “R” (25% of all varieties and genotypes) whereas eight genotypes or varieties showed moderately resistant reaction “MR” and the rest were considered as susceptible “S”.

Eggplant Solanumm elongena L. of fruit vegetables is grown in warm and tropical regions. This plant has mostly been attacked by different pathogen particularly the causal agent of Verticillium wilt (Verticillium dahliae). This is one of the most important diseases that damaged eggplant and reduced yield and fruit quality up to 50%. There has been little successful in control by the use of fungicides, therefore, the resistance of eggplant varieties studied in this research. For this purpose, first the fungal isolates from different areas under eggplant culture were isolated from vascular tissue in Tehran and Alborz province and then purification and pathogenicity test, 15 isolates obtained in pathogeny potential were evaluated by root dip method of the root of Varamini susceptible cultivar in spore suspension with concentrations of 106 spores per ml. Disease severity index calculated by seven numbered scale of Xiao and Lin 1995, after five weeks. The results showed that V-E-KM-2 isolate obtained from samples of infected plants in MohammadShahr in Karaj, with disease severity of 92 percent were identified most virulent as pathogeny. In evaluation stage of the root resistance of different varieties, 14 common cultured eggplant varieties and the present varieties as pathogenicity method, inoculated with spores of the fungus. Symptoms recording were assessed 35 days after inoculation. The results obtained from the analysis of variance showed that treatments are significantly different in probability level of 1%. The means and resistance evaluation of eggplant cultivars against Verticillium wilt showed seven cultivars of Pasargadae, Volentala, Hybrid Arro, Lady, Sohrab, Yek Beauty (1) and Minabella were tolerant (T) in the range of 31.5 to 49.7 of the percentage of disease index. In this following study, supplementary investigations are essential to introduce tolerant varieties for cultivation in Iran.

Cercospora leaf spot disease caused by Cercospora beticola Sacc. is considered to be the most destructive foliar pathogen of sugarbeet which result in highest loss of yield and quality of sugarbeet in warm and humid environments. Control of these fungi often has been unsuccessful by the use of pesticides application; hence, the best method for disease control is the production and implementation of resistant likely cultivars. For this purpose, fungal isolates collected from south and north areas of Iran, Purification and Pathogenicity of isolate the genotype (191), susceptible to disease with spore suspension was implemented on leaves in greenhouse Then for characterizing isolates virulence, like pathogenicity method was performed inoculation of the fungus C. beticola on susceptible (191). The disease severity index after the appearance of disease symptoms, 35 days after sporulating was done by KSW method. Cultivars response assessment, 30 cultivars of sugarbeet to leaf spots in Gharakheyl research station under field conditions was conducted on completely random block design with three replications. Statistics from the infection severity were taken in June and July with an interval of one month. Also for evaluation of genotypes resistance of detached leaf disks in laboratory conditions in sterile environment, 1.8 cm diameter discs were prepared from the leaves of mentioned genotypes and laid on water agar rectangular plates and with spore suspension were sporulated . A total of sampling were obtained 18 isolates of pure C. beticola from different areas that all of them were high virulence, Although in terms of the disease severity were different, but the differences placed in the quantity range between 77.7-98.9 percent. In response Study of 30 genotypes of sugarbeet to causal agent in field conditions, the best time recording of disease severity is done from Gharakhey Ghaemshahr in favorable climatic mid June to late July. In this study, only 5 genotype: 32333, 32335, 32295, 32304 and 32319 showed response moderately susceptible "MS" and the rest of the group were susceptible "S" or very susceptible "VS". It was also determined a high correlation (91%) between assessment of detached leaf disks resistance in laboratory and field conditions as well as these two methods can replace each other