Alternaria spp. and Colletotrichum coccodes in potato leaves with early blight symptoms

Colletotrichum coccodes and Alternaria species are plant pathogenic fungi affecting different organs of potato, tomato, and some other plants. Species-specific primers were applied for the survey of C. coccodes and Alternaria spp. on affected potato leaves collected in different regions of Russia. All studied Alternaria pathogens were present in blighted leaves alone or in the combinations, such as A. alternata + A. solani, A. infectoria + A. alternata, A. solani + A. infectoria. A. alternata (sensu lato) was the most frequent species revealed in 50% of tested potato leaves (alone or in combination with other species). A. solani and A. infectoria were revealed in 30 and 13% of samples, respectively. The presence of a DNA region specific for C. coccodes was detected in DNA samples isolated from potato leaves collected in the Northern Ossetia, Kostroma region, and Mariy El Republic.