First report of horn gall disease of Cinnamomum pseudopedunculatum caused by Laurobasidium hachijoense in the Bonin Islands, Japan

Abstract

In June 2017, deer-horn-like galls covered with a whitish, powdery fungal layer were found on the trunks of Cinnamomum pseudopedunculatum (Lauraceae) in Hahajima, Bonin Islands, Japan. The galls were similar to those of horn gall disease of Ci. tenuifolium caused by Laurobasidium hachijoense (Laurobasidiaceae, Exobasidiales) on Hachijo Island, approximately 700 km north of Hahajima. Based on morphological observation and molecular analyses of ITS and LSU regions, the fungus isolated from the surface of the galls was identified as L. hachijoense. This is the first report of the horn gall disease of Ci. pseudopedunculatum.