Showing 7 results for Rhizoctonia
Bita Naseri,
Volume 5, Issue 2 (8-2016)
Abstract
Naseri B. 2016. Integrated management of Rhizoctonia root rot of bean. Plant Pathology Science 5(2):42-51.
Rhizoctonia root rot caused by Rhizoctonia solani Kühn seriously reduces bean yield. Restricting wide distribution of the disease in main bean growing regions requires identification of factors effect on the disease occurrence and prevalence. Due to the lack of resistant cultivars and ineffective chemical control measures, cultural practice management plays an important role in disease control. According to the findings, increasing soil organic matter, improving rhizoobial nodule formation on root, not planting beans in sandy soils, maintaining nuteral pH of field soil, following 7-9 days irrigation interval throughout growing season, planting standard density of 30 plants per square meter, seeding at less than five cm depth under warm and dry climatic conditions, using sprinkler irrigation, growing red bean in infected fields, appropriate rotation program, applying maximum 50 kg/ha urea, weed control, and seed treatment with proper systemic fungicide should be considered in an integrated management program.
Samaneh Samavat,
Volume 6, Issue 2 (9-2017)
Abstract
Biological control of Rhizoctonia damping-off disease. Plant Pathology Science 6(2):55-67.
Damping-off caused by Rhizoctonia solani J. G. Kühn is a very important plant disease among soil-borne diseases that make severe damages on a wide range of plants in the world. Biological control of this disease with Trichoderma, Gliocladium, Bacillus, Pseudomonas and Rhizobium species has been reported as a successful management method. The results of some researches on this area and the mechanisms of the effect of these antagonistic fungi and bacteria are described here.
Dorna Forghani, Eidi Bazgir, Mehdi Nasr Esfahani, Mostafa Darvishnia,
Volume 9, Issue 2 (8-2020)
Abstract
Forghani D, Bazgir E, Nasr Esfahani M, Darvishnia M (2020) Pathogenicity severity of Iranian isolates of Rhizoctonia solani in Burren potato cultivar. Plant Pathology Science 9(2):63-72. DOI: 10.2982/PPS.9.2.63.
Introduction: Rhizoctonia solani Kühn is a soil borne fungus that causes stem canker and black scurf and severely damages crop in various potato growing areas in Iran. The aim of this study was to investigate the pathogenicity of various fungal isolates from different potato growing areas in Iran on the Burren cultivar. Material and Methods: In this study, The pathogenicity of 70 isolates of Rhizoctonia solani from major potato growing areas in Iran including the provinces of Ardabil, Isfahan, Fars, Kurdistan, Kerman, Lorestan and Hamedan was investigated on the potato cultivar ‘Burren’ in completely randomized design experiment under greenhouse conditions. Results: The analysis of variance showed that the pathogenicity of the isolates was very different at probability level of 1% is significant, and therefore they were divided into different groups. Conclusions: The isolates of Ardabil-1, Ardabil-5, Isfahan-14, Fars-26, Fars-29, Kurdistan-34, Kurdistan-39, Kurdistan-40, Kerman-47 and Hamedan-66 had the highest pathogenicity, while the isolates Fars-21, Isfahan-20, Hamedan-65 and Isfahan-18 showed the lowest pathogenicity, respectively.
Mrs. Mahsa Samiee, Mahdi Davari,
Volume 9, Issue 2 (8-2020)
Abstract
Samiee M, Davari M (2020) Important diseases of turf in Iran. Plant Pathology Science 9(2):119-128. DOI: 10.2982/PPS.9.2.119.
Turf grass is the most important grown plant in urban green space, which functions such as temperature adjustment, increase in relative humidity, air softness and dust absorption. Fungal and fungal-like diseases are the most common lawn diseases in Iran, affecting this plant at all stages of growth, causing its decline. Pythium, Fusarium, Microdochium, Rhizoctonia, Bipolaris, Pyricularia and Colletotrichum species are known as damping-off, root and crown rot, leaf spot and anthracnose pathogens of lawns in Iran. The symptoms of these diseases, the morphological characteristics of pathogens and the methods for their management are described.
Masoumeh Vakili-Ghartavol, Hossein Arouiee, Dr. Shiva Golmohammadzadeh, Mahboobeh Naseri,
Volume 11, Issue 2 (9-2022)
Abstract
Vakili-Ghartavol M, Arouiee H, Golmohammadzadeh S, Naseri M (2022) Optimal methods for the preparation of fungal mycelium for examination with the scanning electron microscope. Plant Pathology Science 11(2):42-51.
Doi: 10.2982/PPS.11.2.42
Introduction: Plant-pathogenic fungi are considered a serious threat to world food security, causing spoilage in plant products and food poisoning. One of the ways to identify fungi is to examine their mycelium using a scanning electron microscope (SEM). In order to take high-resolution microscopic images and obtain the surface properties of mushroom mycelium samples, it is very important to prepare the samples, i.e. the method of dehydrating and drying them. Materials and Methods: In this research, the effect of two dehydration methods and two drying methods on the mycelia of two fungi, Rhizoctonia solani and Rhizopus stolonifer, were compared to study them with SEM. Results: Microscopic observations showed that for R. stolonifer, dehydration with 100% ethanol and drying and for R. solani at room temperature and dehydration with 50% ethanol and the freezing method produce a smooth and high-resolution image compared to other methods. Conclusion: Dehydration of fungal mycelium with 50% to 100% ethanol and drying at room temperature or freezing are the optimal methods to prepare them for examination with SEM and produce a smooth and high-resolution image, and the surface features of their mycelium are preserved and well-defined.
Zahra Mirzaeipour, Eidi Bazgir, Doustmorad Zafari, Mostafa Darvishnia,
Volume 12, Issue 2 (9-2023)
Abstract
Mirzaeipour Z, Bazgir E, Zafari D, Darvishnia M (2023) Effect of temperature and culture medium on the growth and sporulation of eight Trichoderma species. Plant Pathology Science 12(2):105-116. DOI: https://doi.org/10.2982/PPS.12.2.105
Trichoderma species are important agents of biological control of soil-borne plant pathogens. The growth and reproduction of these fungi are influenced by the culture medium and temperature. This study was conducted to determine the effect of temperature and culture medium on the growth and sporulation of Trichoderma species. Ten isolates of Trichoderma species were isolated from agricultural soils of different regions of Lorestan Province, Iran. The study of morphological characteristics and sequencing of ITS-rDNA, and tef1α gene regions showed that they are belong to eight species of Trichoderma. Investigating the effect of four types of culture medium and five temperatures to determine optimum culture medium and temperature for the growth and reproduction of these fungi, showed that the Potato/Dextrose/Agar (PDA) medium is the best, and the temperature of 20 to 30 degrees Celsius is optimal for the growth and reproduction of these fungi. Evaluation of their ability to inhibit the growth of the soil-borne plant pathogenic fungus Rhizoctonia solani in vitro, showed that T. harzianum LT8 has the most inhibition ability. Therefore, this isolate can be used as a potential biocontrol agent for this plant pathogenic fungus in future research.
Hadis Shahbazi,
Volume 13, Issue 1 (2-2024)
Abstract
Shahbazi , H. (2024). Epidemiology and management methods of rice sheath blight disease. Plant Pathology Science, 13(1),42-54.
Sheath blight (ShB) caused by the soil-borne fungus Rhizoctonia solani AG1-IA is one of the most important diseases of rice in the world, which is also common in some areas of rice cultivation in Iran. The pathogen usually overwinters as sclerotia in soil and plant debries and mycelium in plant debris and seeds. Sclerotia can survive inactive in soil, and rice debris for several years. After transplanting susceptible rice cultivars, the sclerotia germinate, produce mycelium, and infect the lower sheaths of the rice plant. The characteristic symptoms of ShB are green-gray water-soaked lesions, spherical to oval, or irregularly discolored on rice sheath. The lesions are connected, and the center of the lesions becomes gray to light brown with a dark brown-to-red border, by passing time. Factors such as the rice variety, plant density, and growth stage, initial inoculum population of the pathogen, environmental conditions, and plant nutrition affect the disease severity and epidemic. The disease management is difficult, because of the wide host range of the pathogen, its ability to survive for a long time in the soil, and the low level of resistance of rice cultivars to it. Proper management such as avoiding cultivation of dwarf and high tillering cultivars in fields with a history of pathogen presence, seed disinfection, proper plant densities, and optimal use of nitrogen fertilizer, field sanitation, and chemical control can prevent the epidemy and damage of the disease.
