Pseudocercospora exilis causing leaf spot disease on Brassica rapa subsp. parachinensis in China.
Chinese flowering cabbage (Brassica rapa subsp. parachinensis) is an important vegetable crop of China and widely cultivated in the southern provinces. From February of 2017-19, a severe leaf spot disease was seen on Chinese flowering cabbage plants in different agricultural fields around Lianzhou and Guangzhou cities of Guangdong, China. Disease incidence reached up to 70% in severely infested fields. Early disease symptoms observed were small circular or irregular spots of brown color, 3 to 11 mm in diameter and often coalesced. The causal pathogen was isolated and identified as Pseudocercospora exilis based on morphological characteristics, molecular data (sequence analysis of the internal transcribed spacer (ITS) and translational elongation factor (EF-1α) regions) and pathogenicity test. This is thought to be the first report of P. exilis causing leaf spot disease on Chinese flowering cabbage.