Powdery mildew caused by Erysiphe necator, is one of the most economically damaging diseases of grapevine throughout the world. This is the first molecular biology study on this fungus in Iran. The aims of the present study were (a) to analyse genetic diversity between isolates of E. necator fungus in four main grape production regions in Iran, i. e., Qazvin, Alamoot, Takestan and Shahriar and ...