First report of Colletotrichum siamense causing leaf spot on silver date palm in China

Silver date palm (Phoenix sylvestris Roxb.) is an important ornamental plant in southern China. In October 2021, a serious anthracnose-like leaf spot of silver date palm was observed at a park in Haikou City, China. Some brown spots with yellow halos around the lesions appeared on the middle and lower leaves of the tree crown. The disease incidence reached 100% of trees and 32.8% of leaves. The pathogen was identified as Colletotrichum siamense by morphological characters, pathogenicity tests and multi-locus phylogenetic analyses combined with ITS, gapdh, tub2, cal and ApMat sequences. This is the first report of C. siamense causing the leaf spot of silver date palm in China.