First report of black leaf spot on Atractylodes lancea caused by Alternaria gaisen in Japan

Abstract

Leaves of Atractylodes lancea, used in traditional Chinese and Japanese herbal medicines developed irregular-shaped brown lesions in Ibaraki, Japan in 2020. We isolated a fungus from the leaf spots, and in pathogenicity tests, the isolate reproduced these symptoms. The isolate was identified as Alternaria gaisen based on conidial morphology and nucleotide sequences of RPB2, GAPDH, and TEF1. This is the first report of leaf spot of At. lancea caused by Al. gaisen.