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Open access

Samavat Samaneh, Asghar Heydari, Hamid Reza Zamanizadeh, Saeed Rezaee and Ali Alizadeh Aliabadi

Abstract

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.

Open access

Razak Mahdizadehnaraghi, Asghar Heydari, Hamid Reza Zamanizadeh, Saeed Rezaee and Jafar Nikan

Abstract

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 above-mentioned 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.

Open access

Soheil Ardakani, Asghar Heydari, Nemat Khorasani, Reza Arjmandi and Majid Ehteshami

Preparation of New Biofungicides Using Antagonistic Bacteria and Mineral Compounds for Controlling Cotton Seedling Damping-Off Disease

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.

Open access

Abbas Heydari, Hossein Kareshki and Mohammad Reza Armat

Summary

The aim of the paper was to develop and validate a scale for estimating the likelihood of a nurse student to become a competent nurse.

Admitting students to nursing schools without assessing their personal characteristics has led to serious consequences, including low quality of nursing care. Early detection of students who are at risk of attrition or becoming non-competent nurses can save the time, money, and energy devoted to educating and training the future nurses.

A mixed methods design will be employed. Using literature review and interviews with nurse students, clinical nurses, nurse experts, and nurse managers during the first qualitative phase, we will build a comprehensive item pool that has a focus on nurse students’ personal characteristics. To increase the trustworthiness of interview findings, we will distinguish competent versus incompetent nurses by measuring their competence levels. In the second quantitative phase, the Nurse Competence Predicting Scale will be developed and tested for psychometric properties.

We believe that Nurse Competence Predicting Scale may help in early identification of nurse students who are at risk of not acquiring expected nurse competencies on graduation or joining the workforce. In such cases, educational managers may take timely remedial interventions.

Open access

Samaneh Samavat, Asghar Heydari, Hamid Reza Zamanizadeh, Saeed Rezaee and Ali Alizadeh Aliabadi

Abstract

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.

Open access

Laleh Naraghi, Asghar Heydari, Hassan Askari, Reza Pourrahim and Rasoul Marzban

Abstract:

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.

Open access

Mojtaba Lashkari, Reza Heydari and Farzaneh Mohamadpour

Abstract

The use of chromium(III) nitrate nonahydrate (Cr(NO3)3·9H2O) as an efficient, mild and economical catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives in the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehydes (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with good yields and short reaction times is reported. The most benefits of this synthetic method include the use of an efficient, eco-friendly, inexpensive and non-toxic catalyst, as well as the solvent-free conditions. All products were characterized by 1H NMR spectroscopy and melting point determination.

Open access

Reza Heydari, Rohollah Rahimi, Mehrnoosh Kangani, Afshin Yazdani-Elah-Abadi and Mojtaba Lashkari

Abstract

The potassium carbonate was applied as a green and efficient catalyst for the one-pot synthesis of pyran annulated heterocyclic systems, via the condensation between aromatic aldehydes, malononitrile and dimedone/1-naphtole by a grinding method at room temperature and solvent-free conditions. Short reaction times, environmentally friendly procedure and excellent yields are the main advantages of this procedure which makes it more economic than other environmentally synthetic methods.

Open access

Hussein Ranjbar, Hossein Karimi Moonaghi, Abbas Heydari, Seyed Reza Mazlom, Laura Scurlock-Evans and Seyedeh Negar Assadi

Summary

Truck drivers are one of the largest occupational groups in Iran. Evidence from previous studies suggests that working and living conditions on the road engender many concerns for truck drivers, and their families and communities. This research aimed to explore the experiences of Iranian truck drivers regarding life on the road.

This qualitative study was conducted among Iranian truck drivers working in the inter-state transportation sector. A purposeful sample of 20 truck drivers took part in this research. Data were collected through semi-structured interviews and analyzed based on qualitative content analysis.

After analysis of the data, three main themes emerged: “Individual impacts related to the hardships of life on the road life”, “Family impacts related to the hardships of road life”, and “Having positive attitude towards work and road”. These findings represent the dimensions of perspectives in the road-life of truck drivers.

Although truck drivers possess positive beliefs about their occupation and life on the road, they and their families face many hardships which should be well understood. They also need support to be better able to solve the road-life concerns they face. This study's findings are useful for occupational programming and in the promotion of health for truck drivers.