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Evaluation of different grape varieties for resistance to powdery mildew caused by Uncinula necator

100%

Khiavi H. K., Shikhlinski H., Ahari A. B., Heydari A.

Journal of Plant Protection Research

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2009

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tom 49

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nr 4

434-439

Powdery mildew is one of the most serious and destructive diseases of grapes around the world including Iran. Although the application of chemical pesticides is the most common control method, the use of resistant varieties may be the most effective and environmentally sound strategy for managing the disease. Fourteen grape varieties were evaluated for testing powdery mildew (Uncinula necator) resistance under natural infection conditions and artificial inoculation methods were used during 2007-2008 in Ardabil province of Iran. Disease severity on leaves and fruit (cluster) were evaluated using Voytovich (1987) procedure. Results of the experiments showed that Shahani, Yagothi and Tabrizkishmishi cultivars were immune, Sahibi cultivar was highly resistant, Agshilig and Tokoulgan were resistant, Kishmishi, Khalili and Tabarzeh cultivars were tolerant, Aldarag and Koupakbogan were susceptible and Garashilig, Seyrakpousteh and Rasmi cultivars were highly susceptible to the disease. In general, results of this study were promising and some immune, highly resistant and resistant cultivars to U. necator were identified and they may be used as a resistance genetic source for management of the disease in national and international programs.

2

Pathogenicity variation and mycelia compatibility groups in Sclerotina sclerotiorum

100%

Irani H., Heydari A., Javan-Nikkhah M., Ibrahimov A. S.

Journal of Plant Protection Research

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2011

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tom 51

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nr 4

Population variability of S. sclerotiorum, the causal agent of Sclerotinia stalk rot of sunflower, was determined by mycelial compatibility grouping (MCG) and pathogenicity variation comparison. To study mycelial compatibility grouping and pathogenicity variability, isolates of S. sclerotiorum were collected from sunflower fields in East, West Azerbaijan and Ardebil provinces of Iran. Among 186 isolates tested, 26 MCGs were identified and 46% were represented by single isolates. There were differences among MCGs comparing mycelial growth rate, sclerotial production on PDA and aggressiveness cause disease. Significant differences were detected in number of sclerotia, dry weight of sclerotia, mycelial growth rate and aggressiveness among MCGs (p < 0.001) regardless of their geographic origins. There was generally a poor correlation (r = 0.21, p ≤ 0.05) between sclerotia weight and number of sclerotia produced on PDA and also to the mycelial growth rate at 24 (r = 0.35, p ≤ 0.05) and 48h (r = 0.39, p ≤ 0.05). Our studies in comparison of the detached leaf and cut-stem methods showed that the highest rank correlations (r = 0.78 p ≤ 0.01), while aggressiveness of two inoculation methods (stem and leaf detached) were not correlated to colony diameter growth or the other two factors. Variation in isolates aggressiveness may be important considerations in disease management systems.

3

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Effectiveness of the chemical stabilizers of Talaromyces flavus in biological control of tomato and greenhouse cucumber vascular wilt disease

100%

Bahramian D., Naraghi L., Heydari A.

Journal of Plant Protection Research

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2016

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tom 56

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nr 3

Fungal antagonist, Talaromyces flavus, is one of the most important biological agents of soil-borne fungal diseases including Verticillium and Fusarium wilt. In this study, to increase the effectiveness of T. flavus isolates obtained from greenhouse cucumbers and field grown tomatoes five chemical stabilizers were evaluated. Based on the results of previous studies, the most effective substrate for the growth, sporulation and stability of T. flavus isolates related to the above-mentioned plants was a mix of rice bran and peat-moss. Different chemical stabilizers were mixed with the above-mentioned substrate containing spore suspensions of various T. flavus isolates. For each plant, a completely randomized experiment was conducted under greenhouse conditions with seven treatments and three replications. The results of this study indicated that treatments containing sodium nitrate and D-cycloserine were more effective than those containing other stabilizers. The overall results of this study suggest that the use of some chemical stabilizers may enhance the biocontrol potential of fungal antagonists in controlling different plant diseases including Verticillium and Fusarium wilt.

4

A comparison between Pseudomonas aureofaciens (chlororaphis) and P. fluorescens in biological control of cotton seedling damping-off disease

88%

Samavat S., Heydari A., Zamanizadeh H. R., Rezaee S., Aliabadi A. A.

Journal of Plant Protection Research

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2014

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tom 54

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nr 2

Due to the importance of the biological control of plant diseases, testing and introducing new biocontrol-active microorganisms is a major concern among plant pathologists. The causal agent of cotton seedling damping-off disease is Rhizoctonia solani. In this regard, we tried to investigate the antagonistic activities of Pseudomonas aureofaciens (chlororaphis) 30–84 (phenazine producing wild type and non-phenazine producing mutant) strains on R. solani, in comparison with some isolates of P. fluorescent under both in vitro (laboratory) and in vivo (greenhouse) conditions. In the laboratory experiment, the inhibitory effects of all the bacteria, on the growth of R. solani, were evaluated using the dual culture procedure. Results showed that five isolates of P. fluorescent along with both strains of P. aureofaciens significantly inhibited the growth of R. solani. Effective bacterial antagonists were then evaluated in a greenhouse experiment where cotton seeds were coated with their suspensions and were sown in pasteurised field-soil. The soil had been pre-inoculated with a virulent isolate of R. solani. The efficacy of the bacterial antagonists was evaluated by counting the number of surviving seedlings in different treatments, at 15 and 60 days after sowing, for determining pre- and post-emergence damping-off incidence. According to the results of the greenhouse experiment, at both intervals, two isolates of P. fluorescens along with both strains of P. aureofaciens caused significant increases in the number of healthy seedlings, in comparison with the untreated control, and a commonly used fungicide (carboxin-thiram). The efficacy of phenazine producing a wild type strain of P. aureofaciens was higher than its non-phenazine producing mutant, indicating that phenazine plays an important role in the antagonistic activity of P. aureofaciens. Effective bacterial antagonists were then studied for their antagonistic mechanisms. The results showed that all four bacteria employed different mechanisms. The bacteria produced siderophore, and volatile metabolites and non-volatile metabolites, in their antagonistic activities. The results of this study suggest that P. auerofaciens may be a new biocontrol agent for controlling cotton seedling mortality disease.

5

Biological control of Polymyxa betae, fungal vector of rhizomania disease of sugar beets in greenhouse conditions

88%

Naraghi L., Heydari A., Askari H., Pourrahim R., Marzban R.

Journal of Plant Protection Research

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2014

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tom 54

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nr 2

Rhizomania is one of the most important diseases of sugar beet around the world – including in Iran. The disease causes a severe decrease in sugar yield and is a limiting factor in sugar beet cultivation. Control of the disease is very difficult due to the long-term survival of its fungal vector (Polymyxa betae) in the soil. In this study, we investigated the effects of antagonistic fungal isolates on the population of the resting structure (cystosorus) of P. betae, under greenhouse conditions. Antagonistic fungi, including Trichoderma harzianum and Talaromyces flavus, were isolated from soil samples collected from sugar beet infested fields in the Semnan Province of Iran. In the next step, their inocula were prepared through reproduction on rice bran. For evaluation of the efficacy of antagonists in greenhouse conditions, a split plot trial was conducted and performed. The main factor was three different methods of application of T. flavus as the soil treatment, seed treatment, and a combination of both methods. The sub-factor was the use of different fungal isolates. To determine the cystosorus population of the fungal vector, seedling roots in all treatments were stained with lactic acid and fuchsine (lactofushine), 60 days after sowing. The number of cystosorus in one gram of root was counted using a light microscope and hemocytometer. At the end of the study, average root weight in different treatments was also measured to select and introduce the best treatments in regard to their effects on root weight. According to the results, the number of cystosorus in 1 g of root was different in various treatments and those treatments containing TF-Su-M-1, TF-Su-M-2, TH-Su-M-1, and TH-Su-M-2 used as a soil application method were more effective in the reduction of the cystosorus population and root weight increase. Among the above-mentioned treatments, maximum reduction of cystosori population and the increase in root weight were observed in TH-Su-M-1 and TF-Su-M-2 through the soil application method.

6

Application of new bioformulations of Pseudomonas aureofaciens for biocontrol of cotton seedling damping-off

88%

Samavat S., Heydari A., Zamanizadeh H. R., Rezaee S., Aliabadi A. A.

Journal of Plant Protection Research

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2014

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tom 54

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nr 4

Pseudomonas aureofaciens (30-84) is a phenazine producing bacterium and reported as asuccessful biocontrol agent of some plant fungal pathogens. In the present study, the possibility of biological control of cotton damping-off caused by Rhizoctonia solani (AG-4) through phenazine production by the 30-84 strain, was investigated. In the search for the development of bioformulations of Pa (m) (PhzR–) and Pa (w) (PhzR+) strains of 30-84, four new carriers including soybean meal (SM), cottonseed meal (CM), rice bran (RB), and talc powder (TAL) were selected. The efficacy of bacterial formulations in reducing disease incidence was evaluated in four intervals (15, 30, 45, and 60 days after sowing), and compared with each bacterial suspension efficacy under green-house conditions. The results revealed that organic carriers were more effective than talc powder. It was also found that all the bioformulations were more efficient than each bacterial suspension. The most effective in reducing disease incidence was Pa (w) + RB. In contrast, Pa (m), Pa (m) + TAL, and Pa (m) + RB did not significantly suppress the disease in comparison with the infested control. Thus, phenazine production as a main biocontrol mechanism of P. aureofaciens (30-84) may be affected by the kind of carriers used for the bioformulation development.

7

Preparation of new biofungicides using antagonistic bacteria and mineral compounds for controlling cotton seedling damping-off disease

88%

Ardakani S. S., Heydari A., Khorasani N. A., Arjmandi R., Ehteshami M.

Journal of Plant Protection Research

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2009

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tom 49

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nr 1

49-55

The overuse of chemical pesticides in agriculture has caused serious environmental problems and thus the demand for safer pesticides is increasing. One alternative is microbial pesticides that suppress plant pathogens via their microbial activities. As microbial pesticides are eco-friendly products, in this study we prepared four biological fungicides using two isolates of Pseudomonas fluorescens that included a talc-based powder and bentonite-based powder as mineral carriers. Then we evaluated the efficacy of these products in controlling cotton seedlings, damping-off, a fungal disease caused by Rhizoctonia solani at four intervals of 15, 30, 45 and 60 days after sowing the cotton seeds under greenhouse conditions. The results of greenhouse experiment on application of biofungicides showed that the efficacy of Bentonite-B1 treatment to control R. solani was promising as it increased the number of healthy seedlings 3.42 to 3.57 - fold and was much more effective than the carboxin/thiram fungicide in all stages.

8

Evaluation of Pseudomonas and Bacillus Bacterial Antagonists for Biological Control of Cotton Verticillium Wilt Disease

88%

Mansoori M., Heydari A., Hassanzadeh N., Rezaee S., Naraghi L.

Journal of Plant Protection Research

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2013

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tom 53

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nr 2

Verticillium wilt is considered the most important disease of cotton in the world, including Iran. Cultural practices and the use of resistant varieties are the most common strategies used to control Verticillium wilt of cotton. These strategies are not always available or effective. In recent years, biological control using fungal and bacterial antagonists, has been applied to control some cotton diseases including damping-off. In this study, we investigated the possibility of biological control of Verticillium wilt of cotton using bacterial antagonists. Suspension of eight bacterial strains of Pseudomonas fluorescens and Bacillus spp. isolated from different rhizospheric soils and plant roots in the Iranian cotton fields, were prepared with a concentration of 108 cfu/ml. Ten cotton seeds (cv Varamin) were then coated with each bacterial suspension and were planted in soil pre-inoculated with Verticillium dahliae microsclerotia. The efficacy of bacterial antagonists in reducing wilt disease was evaluated by determination of the disease index in different treatments. The results indicated that most isolates were effective in reducing disease (compared to the untreated control) 90 days after sowing. Isolates B5, B6, B2, B7, and B3 were the most effective, respectively, in reducing wilt index. In contrast, isolates B1, B4, and B8 did not significantly reduce the disease. In general, P. fluorescens isolates were more effective than Bacillus isolates. This study suggests that bacterial antagonists might be potential biological control agents of cotton.

9

Biological control of garlic (Allium) white rot disease using antagonistic fungi-based bioformulations

88%

Mahdizadehnaraghi R., Heydari A., Zamanizadeh H. R., Rezaee S., Nikan J.

Journal of Plant Protection Research

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2015

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tom 55

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nr 2

White rot disease caused by Sclerotium cepivorum is a major yield reducing fungal disease of garlic found throughout the world, including Iran. The use of chemical fungicides is the most common control method for the disease at the present time. This control measure is costly, contaminates the environment, and harms non-target organisms. Moreover, since the pathogen is soil-borne, chemical control strategy is not quite effective against the disease. In this study, we tried to develop and prepare some new bioformulations based on three antagonistic fungal species: Trichoderma harzianum, T. asperellum, and Talaromyces flavus. Six isolates of the abovementioned fungi were used along with the organic and inorganic carriers, rice bran and talc, to develop twelve new bioformulations. The effectiveness of the bioformulations were then evaluated in the control of garlic white rot disease in the greenhouse conditions in comparison with the healthy control, infected control, and the commonly used fungicide Carbendazim. The design of the experiment was completely randomised. There were 15 treatments each, with four replicates. The results of the greenhouse experiments indicated that almost all the developed bioformulations resulted in significant reductions (34.50 to 64.50%) in the incidence of white rot disease. In general, bioformulations which contained the organic carrier (rice bran) performed more effectively than those that contained the inorganic carrier (talc). Bioformulations which contained an organic carrier (rice bran) were as effective as the fungicide Carbendazim.

10

Controlling sugar beet mortality disease by application of new bioformulations

76%

Jorjani M., Heydari A., Zamanizadeh H. R., Rezaee S., Naraghi L., Zamzami P.

Journal of Plant Protection Research

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2012

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tom 52

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nr 3

There is growing interests in the use of biological approaches to replace or reduce the application of chemical pesticides in modern agriculture. In this regard, antagonistic fungi and particularly bacteria have proved to be potential candidates. In the search for efficient alternative biofungicides, eight new Bioformulations were developed and prepared using two strains of Pseudomonas fluorescens (B1) and Bacillus coagulans (B2) isolated from different rhizospheric soils and plant roots of Iranian sugar beet fields. Bioformulations were developed using procedures described in the literature. Bioformulations included a talc-based powder and bentonite-based powder as inorganic carriers, and peat and rice bran as organic carriers. The results of our greenhouse experiment, where these bioformulations were applied to sugar beet seeds to control seedling mortality disease, showed that most of the treatments at different intervals (15, 30, 45 and 60 days after sowing) were effective in reducing the disease (compared to the untreated control). According to the results, six out of eight of the developed bioformulations, including Peat-B1, Peat-B2, R.B.-B2, Bent.-B1, Talc-B1 and Talc-B2, were more effective than commonly used fungicides (Carboxin-thiram) in controlling sugar beet mortality disease. Yet, two bioformulations (R.B.-B1 and Bent.-B2) were less effective than carboxin-thiram in the reduction of the disease incidence.

11

Biological control of tomato verticillium wilt disease by Talaromyces flavus

76%

Naraghi L., Heydari A., Rezaee S., Razavi M., Jahanifar H., Khaledi E. M.

Journal of Plant Protection Research

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2010

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tom 50

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nr 3

In this study, Talaromyces flavus a fungal antagonist, was isolated from soil samples collected from tomato fields in Tehran and the Western Azarbayjan provinces of Iran.Antagonistic effects of T. flavus isolates against Verticillium albo-atrum (V. a.-a.), the causal agent of tomato wilt disease were investigated under laboratory and greenhouse conditions. Soil samples from tomato fields in the Varamin and Uremia regions of Tehran and the Western Azarbayjan provinces respectively, were cultured on selective medium. T.flavus colonies were recovered after three weeks. In the laboratory experiments, antagonistic effects of volatile and non-volatile extracts of T. flavus isolates on V. a.-a.growth were investigated. Among isolates, five that caused higher growth inhibition of V. a.-a. were selected for greenhouse experiments. In the greenhouse, first inoculum of V. a.-a. and treatments affected by T. flavus isolates were prepared. For comparison of the infection index in treatments, the greenhouse experiment wasperformed with a split plot arranged in a randomized complete block design with four replications. Result of greenhouse experiments on different types of T.flavus treatments indicated that there was no significant difference among them. However, among five T. flavus isolates, the most effective one was Tf-To-V-24 and Tf-To-U-36. In the experiment on the interaction between different T. flavus treatments and T. flavus isolates,a minimum infection index was observed when both soil and seed were treated with Tf-To-V-31. The overall results of this study show that it may be possible to manage tomato Verticillium wilt disease effectively by T. flavus.

Ograniczanie wyników

Evaluation of different grape varieties for resistance to powdery mildew caused by Uncinula necator

Pathogenicity variation and mycelia compatibility groups in Sclerotina sclerotiorum

Effectiveness of the chemical stabilizers of Talaromyces flavus in biological control of tomato and greenhouse cucumber vascular wilt disease

A comparison between Pseudomonas aureofaciens (chlororaphis) and P. fluorescens in biological control of cotton seedling damping-off disease

Biological control of Polymyxa betae, fungal vector of rhizomania disease of sugar beets in greenhouse conditions

Application of new bioformulations of Pseudomonas aureofaciens for biocontrol of cotton seedling damping-off

Preparation of new biofungicides using antagonistic bacteria and mineral compounds for controlling cotton seedling damping-off disease

Evaluation of Pseudomonas and Bacillus Bacterial Antagonists for Biological Control of Cotton Verticillium Wilt Disease

Biological control of garlic (Allium) white rot disease using antagonistic fungi-based bioformulations

Controlling sugar beet mortality disease by application of new bioformulations

Biological control of tomato verticillium wilt disease by Talaromyces flavus