First report of Neofusicoccum parvum causing leaf target-spot disease on Ficus carica L. in China

Figs (Ficus carica L.) are widely cultivated throughout the world owing to their excellent medical and edible value. In October 2021, we discovered a new leaf target-spot disease associated with the common fig in China. It is necessary to identify the causal agent, as it seriously affects the normal growth of figs and reduces their economic value. The initially infected leaves displayed light yellow lesions between the leaf veins. Under conditions of suitable temperature and humidity, the lesions expanded rapidly with light brown in the middle and dark brown at the margin accompanied by a yellow halo, and typical target holes appeared in the centre of the lesions. Three filamentous fungi were isolated from infected leaves, among which the isolate WHG-3 exerted the strongest virulence in vitro. Its newly grown mycelia were white and then gradually turned to dark grey. The conidia were hyaline, spindle-shaped or oval, with thin cell walls. Phylogenetic analyses based on the ITS, tef-1 and tub2 gene sequences verified that the isolates WHG-3, WHG-4 and WHG-5 were Neofusicoccum parvum. To the best of our knowledge, this is the first report that N. parvum causes leaf target-spot on Ficus carica L. in China.