First report of Colletotrichum brevisporum causing anthracnose on pumpkin in China.
In the summer of 2015, dark brown lesions were observed on green husk pumpkin cultivar Xiangli No. 23, in Changchun, Jilin Province, China. Nearly half of the plants in a 0.01-ha field of pumpkin were symptomatic. Symptoms on fruit were initially irregular dark green spots of 2 mm in diameter. As the disease progressed, spots expanded and gradually became round or oval, and the outside and inside of the necrotic areas became black. With higher humidity, abundant white aerial mycelia were produced on the black disease spots and orange conidial cirrhi visible in concentric rings on the margins of the lesions, and fewer acervuli were seen. Finally, the fruit were rotten. Based on morphological characteristics, molecular data (internal transcribed spacer, β-tubulin, actin and chitin synthase gene regions) and pathogenicity tests, the causal agent was identified as C. brevisporum. This pathogen has been previously reported on Pandanus pygmaeus and Lycium chinense in Thailand and Korea, on fruits of Carica papaya and Sechium edule in Brazil, and on pepper fruits in China. This is thought to be the first report of C. brevisporum causing anthracnose on green husk pumpkins.