The Effects of Arbuscular Mycorrhizal Fungi on Development of Cotton Plants and Verticillium Wilt ((Verticillium dahliae Kleb.)

This study was aimed to investigate the effects of mycorrhizal fungi glomus coledonium, g. etunicatum, g. fasciculatus, g. intraradices, g. mosseae, gigaspora margarita on plant development parameters of cotton and diseases severity of wilt caused by verticillium dahliae. the root colonisation ratio of mycorrhizal fungi at the condition of v. dahliae inoculation or not, changed between 38.9-67.8% and 11.5-57.0%, respectively. the highest colonisation ratio were provided by g.mosseae, g. etunicatum and g. fasciculatus species. mycorrhizal fungi increased the length of plant, number of leaf, fresh and dry weight of plants; however verticillium dahliae inoculation caused decrease the plant growth parameters. the highest increase in plant growth parameters in the presence and absence of v. dahliae was achieved by g. mosseae and the lowest by g. coledonium. in pre-inoculated plants by mycorrhizal fungi, the diseases severity was decreased by %31.3-65.6. g. mosseae and g. etunicatum were the most effective species by the decrease of the disease severity. consequently, g. mosseae and g. etunicatum identified as promising biological control agents because of the effects of both increasing the plant growth parameters and reducing the disease severity.