Guignardia bidwellii causes leaf spot on Boston ivy in South Korea

Abstract

A severe outbreak of leaf spot was observed on Boston ivy (Parthenocissus tricuspidata) in Jinju, South Korea, during 2012 and 2013. DNA sequencing and phylogenetic analysis of the internal transcribed spacer rRNA gene region identified the isolates as Guignardia bidwellii, and Koch’s postulates were supported by pathogenicity tests conducted on healthy plants. Based on mycological characteristics, pathogenicity tests, and molecular analyses, the causal fungus was confirmed to be G. bidwellii. To our knowledge, this is the first report of leaf spot caused by G. bidwellii on Boston ivy in South Korea.