عنوان مقاله [English]
One of the most important and epidemic diseases of potato in many parts of the world, especially in Iran is early blight (EB), which includes two species of fungi Alternaria genus A. solani and A. alternata causing considerable damages every year, imposing significant loses to this product. Given the importance of reducing the use of pesticides, achievement of cultivars resistant and or tolerant ones and also, knowing their reaction mechanisms, morphological characteristics of the 24 commercial cultivars leaves, commonly grown in the country, were studied in vitro and greenhouse. The trails for determining resistance scales and anatomical characteristics of the leaves, indicated that, there is a direct relations between resistant cultivars, Diamanté, Ramos, Satina and Senate with the more thickness of their cuticle, wax and epidermal layers in the outer skin layer of the leaves, also higher number and height of the corks and stomata of the leaf, compering to susceptible ones to early blight disease. Whereas, the relations for the susceptible and moderately susceptible cultivars, Mileva, Cosima, Premier, Santé, Atlantic, Arinda, Shepody, Marquis and Agria were reversed. So, the traits were far less in susceptible cultivars as were measured. These studies open new horizons in the diagnosis and access to resistant varieties in the coming future.