Zonate leaf spot of Ailanthus altissima in Korea is caused by Boeremia exigua

Abstract

Zonate leaf spot of Ailanthus altissima presumed to be associated with an Ascochyta sp. has been observed in Korea where the species is naturalized. Using microscopic examinations of 22 specimens, deposited in the Korea University herbarium since 1989, and molecular phylogenetic analyses of three monoconidial isolates, we identified the isolates as Boeremia exigua. Pathogenicity of the fungus was confirmed by fulfilling Koch's postulates. These results indicated that the previous records of Ascochyta ailanthi and Ascochyta sp. on A. altissima should be re-evaluated to confirm the identity of the species.