جداسازی باکتریهای اندوفیت گوجه فرنگی و ارزیابی کارآیی آنها در بیوکنترل عامل بیماری پژمردگی ورتیسیلیومی

The tomato (Lycopersicon esculentum Mill) is one of the most commercial crop in the world and Iran. Since tomato is a product with a short growth period and high yield, its cultivated area is increasing. Verticillium wilt of tomato is one of the obstacles to cultivation in different parts of the country. The use of entophytic bacteria is one of the new ways to manage this disease. These bacteria colonize the tissues of the plant and in a symbiosis interaction, supply their food from the plant tissues and protect the host plant against biotic and abiotic stresses. In this research, the entophytic bacteria of tomato plants was isolated and their role in controlling Verticillium wilt disease of tomato was evaluated. At first, plant samples were collected from greenhouses and fields in Tehran and Alborz provinces. Then, roots, stems, leaves and fruits of plants were completely mashed after sterile disinfection with sodium hypochlorite and alcohol 70% and thoroughly washed with sterilized distilled water. Afterwards, they were cultured on NA culture. Then, the Petri plates were incubated at 27 ° C for one week. Single colonies were selected and purified on NA culture. A total of 688 bacterial isolates were isolated from different organs of root, stem, leaf and fruit of tomato. Based on hypersensitive reaction on tobacco and basic biochemical tests, 128 isolates were selected. In the second series, based on biochemical tests and final grouping, 68 isolates were selected. For evaluating of the efficacy in germination and plant growth promotion, 68 bacterial isolates were tested on tomato seeds/seedlings on two cultivars of Falat and Superenbar under laboratory and greenhouse conditions. The results showed that the germination percentage of the seeds varied from 40% to a maximum of 100%. In this screening, Falat cultivars and 39 isolates of endophyte were selected, which will be used for supplementary tests. Dominant isolates was related to Bacillus spp., Pseudomonas spp. and Enterobacter spp. Evaluation of selected bacteria in controlling the disease in greenhouse is being performed.