NEW ALTERNARIA SPECIES ASSOCIATED WITH POTATO LEAF SPOT IN VARIOUS POTATO GROWING REGION OF IRAN

Early blight caused by Alternaria spp. highly influences potato production annually. It has become an important disease in major potato growing regions of Iran. Over 270 samples of potato infected leaves have been collected from various potato fields of Isfahan, Ardabil, Khuzestan, Hamedan, Semnan and Khorasan Razavi provinces. Base on morphological studies six Alternaria species i.e. Alternaria alternata, A. tenuissima, A. dumosa, A. solani, A. arborescens and A. infectoria have been identified. This is the first report of two pathogenic species A. infectoria and A. tenuissima on potato in Iran. Two species of A. alternata and A. tenuissima, were the most prevalent species found in the studied regions.