Plant Pathology Science

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Early blight is an important worldwide disease of tomato that farmers must have frequent spray chemicals to control it. One way to reduce the use of pesticides, costs of production and the risk of environmental pollution, spraying based on forecasting of TOMCAST system, which is based on the time of wet leaves and temperature during tomato growing season in each region, predict disease severity , and determine suitable time of spraying. Application this system, in some countries considerably reduced pesticides usage on tomato. This system predict time of spraying when needed and has maximum effect. By using this forecasting method in Iran, can reduce pesticides usage on this freshly consume fruit, efficiency of using pesticides, and increase yield. 

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Metabolomics or analysis of all cellular metabolites is a new and powerful tool that provides possible quick view to the large number of small molecules (metabolites) within the cell and indicates dynamics of these molecules under different conditions. Quantitative and qualitative measurements of large number of cellular metabolites provide a broad view of the biochemical status of an organism that can be used to monitor and assess gene function. Today, metabolomics is widely being used in agriculture for classification of plants, studying phytochemical diversity of medicinal plants, assessment of the changes which occur in the biochemical composition of foods occurring, for example, during the pasteurization of Basmati rice for long-term storage or the boiling for direct consumption. In plant pathology, metabolomics has been mainly used to study plant responses to a wide range of biotic or abiotic stresses including resistance of plants to pathogens and also as a powerful tool for functional genomics studies. Profiling of the transcriptome and proteome has received some criticism due to their inability to predict gene function but profiling of the metabolites is promising as it provides instantaneous large amounts of data from cell physiology. Study of plant genetic resistance is one of the most important applications of metabolomics. Since metabolites are final products of gene expression and all changes in gene expression is reflected in metabolite profiles, hence metabolite profiles produce a more comprehensive understanding of plant defense mechanisms against stresses such as pathogen challenge. On the other hand, breeders are looking for rapid, simple and accurate tools for identifying metabolites associated with resistance as biomarker for screening cultivars resistant to diseases. In addition, understanding resistance mechanisms at the level of metabolome may help breeders for better understanding of resistant gene function and pyramiding suitable resistant gene in elite cultivar. This article is a review of the science, its applications in plant pathology, methods of study metabolites and their administrative problems.

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Food production and food security is an essential precursor to sustainable development in agriculture. Currently, more than 800 million people, generally in Africa and Asia, suffer from hunger and agriculture is considered as the main source of food for them. One of the application of nuclear technology is reducing the damages of plant pest and diseases. The application of nuclear techniques in plant pathology can be grouped in three categories including disease tracing, mutagenesis induction and radiation of crops to induce resistance and destruction of pathogens. As a new method to induce defense responses to biotic and abiotic stresses, nowadays, gamma radiation is used to improve the growth in the way to induce the plant resistance to environmental tensions and plant pathogens as well. Use of this potential, especially in management of seed and seedling diseases is very important to reduce a big portion of crop losses caused by plant pathogens in the first weeks of seedling growth.