First report of Stemphylium lycopersici causing leaf spot on hot pepper in China

Abstract

Hot pepper is an exceedingly popular vegetable crop in China and is cultivated on 737 hectares in Beijing. A severe leaf disease with typical symptoms of spots with grey centres and dark brown borders was observed on hot pepper plants in Beijing in the winter of 2016. More than 50% of all plants in the region were infected. Fungal cultures were isolated from naturally infected leaf tissue, and identified as Stemphylium lycopersici based on morphological features, cultural characteristics and molecular identification by sequencing the ITS, gpd and cmdA genes. Pathogenicity was determined by inoculating healthy pepper plants with hyphal suspensions, and the fungus was re-isolated from developing lesions on the inoculated plants, thus fulfilling Koch’s postulates. This is the first report of natural infection by S. lycopersici causing leaf spot on hot pepper in China.