Characterization of Alternaria species associated with black spot of strawberry in Beijing municipality of China

Abstract

Strawberry black spot caused by Alternaria is an important foliar disease. In 2016, strawberry leaves with severe black spot lesions were collected from eight districts of Beijing municipality in China. Molecular and morphological criteria were matched to identify the Alternaria species inciting strawberry black spot in Beijing. A total of 102 Alternaria isolates from diseased strawberry leaves were divided into two species: A. tenuissima (61 isolates, 59.8%) and A. alternata (41 isolates, 40.2%). The detached leaves of strawberry showed typical black spot symptoms when inoculated with spore suspensions of isolates of A. tenuissima and A. alternata, with disease incidence ranging from 20.4–100.0% and disease index ranging from 6.0–29.1, respectively. To our knowledge, this is the first report of A. tenuissima and A. alternata causing black spot of strawberry in Beijing, China.