Abstract:

Black spot is an important worldwide fungal disease in Cruciferae vegetables. It can spread far away through seed carrying, which can harm the leaves, stems, fruits and other parts of Cruciferae vegetables, causing serious quality and yield losses. Black spot is caused by three specialized pathogens, including Alternaria brassicicola, Alternaria brassicae, and Alternaria japonica. Black spot of Cruciferae vegetables in southern China is mostly caused by Alternaria brassicicola. In order to clarify the damage status of black spot in Zhejiang Province, this study used molecular identification techniques to investigate the infection host and distribution range of Alternaria brassicicola in the whole province. The results indicated the number of detected Alternaria brassicicola in the five major categories of Cruciferae host plants from high to low was Chinese cabbage> rapeseed> mustard>cabbage>radish. Among the 89 districts or counties in 11 prefecture-level cities, Alternaria brassicicola was detected in 27 districts or counties, accounting for 30.3%, and Alternaria brassicicola was detected in 9 cities, accounting for 81.8%. Alternaria brassicicola is widely distributed across Zhejiang Province and poses a significant threat to numerous host plants. Therefore, it is essential to strengthen control and prevention efforts.

Key words: black spot, Alternaria brassicicola, host, distribution area