Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First report of leaf spot caused by Alternaria alternata on ginseng (Panax ginseng) in China.

Abstract

Ginseng (P. ginseng) is a perennial herbaceous plant and a precious traditional Chinese medicine, widely cultivated in Asia, particularly the Changbai Mountain area in China. Alternaria panax was reported as the main cause of Alternaria leaf spot of ginseng; however, a small-spored Alternaria species was isolated from leaf spot symptoms during recent surveys. During 2017, leaf spot disease of P. ginseng was observed in the Fusong district, Jilin, China. The disease was widespread, with 20 to 30% of the fields affected. Leaves of the affected plants showed brown to black necrotic spots. The fungus was isolated from symptomatic leaves on potato dextrose agar and characterized morphologically under the microscope. Based on morphological characteristics, molecular data (sequence analysis of the rDNA internal transcribed spacer, endopolygalacturonase, Alternaria major allergen, portion of the histone 3, elongation factor 1-alpha, RNA polymerase II 2nd largest subunit and glyceraldehyde 3-phosphate dehydrogenase gene) and pathogenicity tests, the causal agent was identified as A. alternata. A. alternata causing leaf spot of American ginseng was reported in China. Also, leaf spot of Panax notoginseng caused by A. alternata was reported in China. This is thought to be the first report of A. alternata on P. ginseng in China.