A New Pathogen of Plantain. S. M. Yang, USDA/ARS, Foreign Disease-Weed Science Research, Bldg. 1301, Ft. Detrick, Frederick, MD 21702 . S. C. Jong and F. M. Dugan, ATCC, Rockville, MD 20852. Plant Dis. 80:1429. Accepted for publication 8 October 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-1429C.
Two plantain plants (Plantago lanceolata L.) showing circular to irregularly shaped brown spots were collected at Karaj and Dastjerd, Iran, by S. Eskandari in August 1994. A fungus isolated from the lesions was identified as Alternaria conjuncta Simmons (ATCC 200052). Sections of potato dextrose agar (0.7 cm in diameter) with mycelium from 2- to 4-day-old cultures of A conjuncta were placed on leaves of plantain plants and incubated in a dew chamber at 22 to 25°C for 40 to 48 h. Brown lesions (0.5 to 1.2 cm) that looked like the original lesions developed at inoculation sites. Plants inoculated with pieces of agar without mycelium served as controls in each test and showed no lesions. A. conjuncta was reisolated from the lesions of inoculated plants, thus confirming the infectivity of this fungus. This is the first report of A. conjuncta as a pathogen of plantain.