Leaf spot of Kerria japonica caused by Diaporthe pescicola in China

摘要

This article reports the first known occurrence of leaf spot of Kerria japonica caused by Diaporthe pescicola in China and worldwide. Leaves of K. japonica with leaf spot symptoms were collected in September 2020 from Nanjing, Jiangsu, China. Leaf lesions were of irregular shape and sizes forming mostly in the middle of the leaves, and most of the lesions were white and hazel in colour. A fungus was isolated from diseased leaves and identified as Diaporthe pescicola based on morphological features and multigene phylogenetic analysis of the internal transcribed spacer (ITS) region, elongation factor 1-alpha (EF1-alpha), beta-tubulin (beta-tub), histone H3 (HIS) and calmodulin (CAL) genes. Three strains of isolated fungus caused leaf spot symptoms on inoculated wounded leaves of K. japonica, which were similar to the natural symptoms observed in the field. This disease greatly reduces the ornamental value of affected plants, and identification of the pathogen is significant for the prevention and control of the disease.