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.
Toktam Selahvarzi, Bahram Abedy, Dr. Nasser Beikzadeh,
Volume 13, Issue 1 (2-2024)
Abstract
Selahvarzi, T., Abedy, B., & Beikzadeh, N. (2024). The impact of Osage orange fruit and leaf aqueous and ethanolic extracts on Erwinia amylovora, the cause of apple and pear fireblight. Plant Pathology Science, 13(1), 75-88.
Fire blight caused by Erwinia amylovora is one of the most important diseases of apple and pear trees in the world. The purpose of this research was to determine the antibacterial effect of the ethanolic and aqueous extracts of the fruit and leaf of the Osage orange (Maclura pomifera) against the cause of this disease. The effect of ethanolic and aqueous extracts of leaf and fruit of this plant on the growth of
E. amylovora colony in eight concentrations was tested by disk diffusion method. Antioxidant activity and total phenol of these extracts were also measured. The experiment was conducted as a factorial in a completely randomized design with four replications for each treatment in laboratory conditions. The results showed that the type of extract and plant organ are effective in the antibacterial properties, antioxidant activity, and the amount of total phenol. The ethanolic extract of the fruit, at a concentration of 1000 mg/ml with an average diameter 5.57 mm inhibitory halo had the highest inhibitory effect against E. amylovora, antioxidant activity, and total phenol content, while the aqueous extract of the fruit and the aqueous and ethanolic extracts of the leaf weren't significantly effective. Therefore, the ethanolic extract of Osage orange fruit has an inhibitory effect on the growth of E. amylovora colony and can be considered as a natural compound in the management of the disease.
Safar Nikmaram, Mehdi Sadravi, Mostafa Ghaderi Zefrehee,
Volume 13, Issue 1 (2-2024)
Abstract
Nikmaram, S., Sadravi, M., & Ghaderi Zefrehee, M. (2024). The impact of three arbuscular mycorrhizal fungi on wheat take-all disease caused by Gaeumannomyces graminis var. tritici. Plant Pathology Science, 13(1), 104-112.
Take-all caused by soil-borne fungus Gaeumannomyces graminis var. tritici is one of the most important diseases of wheat in the world, reported to cause up to 50% yield losses. The disease has also been reported from different areas of wheat cultivation in Iran. Biological control is a healthy and environment-friendly method for managing plant diseases, and arbuscular mycorrhizal fungi can play an important role in this field. This research was conducted to determine the effect of three arbuscular mycorrhizal fungi on the severity of this disease. The pathogen was isolated from diseased wheat plants in Kigiluyeh and Boyar-Ahmad Province, southwestern Iran. The effect of three arbuscular mycorrhizal fungi; Funneliformis mosseae, Rhizoglomus intraradices, and Blaszkowskia deserticola alone, and in combination on the disease severity and growth indices of wheat was tested under greenhouse conditions in a completely randomized design. All treatments of mycorrhizal fungi reduced disease severity and increased growth indices compared to control plants, but F. mosseae was more effective than others. Therefor
F. mosseae can be used to reduce the severity of the disease and improve the growth indices of wheat.
Seyyedehatefeh Hosseini, Zahra Anvari,
Volume 13, Issue 1 (2-2024)
Abstract
Hosseini, S. A., & Anvari, Z. (2024). Application of new information technologies in plant pathology. Plant Pathology Science, 13(1),135-148.
Population growth has put significant pressure on the food supply chain, making it even more challenging to ensure that everyone has access to adequate, healthy, and nutritious food. The use of new information technologies based on artificial intelligence in agriculture can play a significant role in increasing the production of healthy plant products and ensuring food security for humans. All plant crops are highly vulnerable to diseases and timely and correct management of diseases is essential to optimize their production. New information technologies such as remote sensing, analysis of plant absorption light spectra, and the use of specialized Internet software for the diagnosis of plant diseases on mobile phones can help in the rapid and accurate diagnosis of diseases, the implementation of a forecasting program and their monitoring to prevent their spread, and the timely implementation of their management methods. The unique applications of these new information technologies in the identification, monitoring and management of plant diseases are described in this article.
Dr. Mina Rastgou, Siroos Honarvar,
Volume 13, Issue 1 (2-2024)
Abstract
Rastgou, M., & Honarvar, S. (2024). Application of phages for biological control of plants pathogenic bacteria. Plant Pathology Science, 13(1),55-64.
Pathogenic bacteria are one of the most important factors in reducing the yield of plant products. In the past, the management of these pathogens was limited to the use of antibacterial compounds or resistance inducers, but with the discovery of bacteriophages in recent decades, attention to their use has increased. Bacteriophages or phages are viruses that specifically affect bacterial cells. Currently, hundreds of bacteriophages have been isolated and tested against plant pathogenic bacteria, and there are still many more that need to be investigated. This approach requires special protocols to identify new phages, understand the emergence of phage-resistant clones and the infectivity of other bacterial species. Phage therapy or the use of phages to biological control plant pathogenic bacteria due to its cheapness, very high specificity of phages against bacteria, no negative effect on humans or animals, and no environmental pollution, as a suitable method to control these pathogens can be considered.
Asaad Chaseb Kouin, Khadijeh Abbasi, Labeed Al-Saad, Somayeh Hajinia,
Volume 13, Issue 2 (9-2024)
Abstract
Early blight, caused by Alternaria alternata, is a major tomato disease that leads to significant economic losses. This study aimed to evaluate the effectiveness of two fungi, Funeliformis mosseae and Trichoderma harzianum, as potential biological control agents against the disease. Initially, the inhibitory effect of T. harzianum on the pathogen's colony growth was assessed under laboratory conditions using the dual-culture method, where T. harzianum reduced pathogen colony growth by 70%. Subsequently, the efficacy of F. mosseae and T. harzianum, applied individually and in combination, was tested against A. alternata in greenhouse conditions using a completely randomized design with three replications per treatment. Various parameters were measured, including chlorophyll a, b, and total content; total phenol; activities of catalase and peroxidase enzymes; and plant growth traits such as stem number, stem height, fresh and dry weight of aerial parts, root length, and fresh and dry weight of roots. Statistical analysis revealed that the application of T. harzianum and F. mosseae enhanced antioxidant enzyme activity (catalase and peroxidase) and phenolic compound levels, leading to improved growth and increased dry matter content in tomatoes under pathogen infection conditions.
Ms. Kimia Hasani, Dr. Fatemeh Shahryari,
Volume 13, Issue 2 (9-2024)
Abstract
The genus Streptomyces belongs to the actinomycetes, which is an aerobic, gram-positive and multicellular bacterium. The members of this genus are mostly known as soil-dwelling bacteria. However, they are found in various environments such as marine sediments, freshwater ecosystems, symbiotic with insects and sponges, and plant endophytes. In particular, only a few pathogenic species of this genus have been identified that cause disease in plants and humans. Beyond the range of distribution, specific genomic features, unusual mushroom-like growth mode, impressive metabolic capabilities, including the ability to produce diverse antibiotics and other bioactive natural products, have made members of this genus attractive organisms for study. They are also among the most promising microorganisms for improving the overall health of the soil and increasing agricultural productivity. Approximately two-thirds of all known actinomycete antibiotics are produced primarily by members of this genus. The metabolites of this genus have a wide spectrum including cyclic and linear peptides, terpenoids, macrolactams, macrolides, glycosides, polyaromatics and linear polyketides. The discovery of numerous and different compounds shows the high potential of Streptomyces as a source of new and interesting natural products.
Mrs Fatemeh Soltani Tale, Dr. Leila Kashi, Dr. Doostmorad Zafari,
Volume 13, Issue 2 (9-2024)
Abstract
Today, with the increase in cucumber cultivation in greenhouses and fields, their contamination with root-knot nematodes is observed in some areas. The effect of three Trichoderma species (T. crassum, T. harzianum and T. afroharzianum) with liquid organic sulfur of Raskood company on the control of root-knot nematode (Meloidogyne javanica) on cucumber (Nagin variety) was investigated with two separeted tests under greenhouse conditions, in this research. Both tests were done with eight treatments (the use of each of the mushrooms together with sulfur, each of the fungi alone and sulfur alone and the infected control) in five repetitions and the form of Completely Randomized Design with Duncan's test at 5% level. In order to infect the plants, 2500 second-stage larvae and nematode eggs were added to each kilogram of potting soil containing cucumber seedlings at the four-leaf stage. Then, depending on the type of treatment, one milliliter of Trichoderma suspension (106 spores per milliliter) and sulfur were added to each seedling, and the pots were investigated after 45 and 60 days for the first and second tests, respectively. Data analysis was done using SAS 9.4 software. The results of this study showed that in both tests, the use of sulfur with each of the fungi and sulfur alone led to significant differences between the plant growth indicators of tretments (fresh and dry weight of aerial organs, lenght of the root and aerial organs) and control. Also, nematode pathogenicity factors (the number of second stage larvae in the soil, the number of female nematodes in each gall, the number of female nematodes in the whole root, the number of galls in the whole root, the number of egg mass in each gall, the number of egg mass in the whole The root and reproduction factor) of the treatments that with both of Tricoderma and sulfur together, as well as the treatment using sulfur alone showed a significant difference compared to the control. However, in the both of tests, the most effective treatments were related to the use of T. crassum together with sulfur.
