Wilt, Crown, and Root Rot of Common Rose Mallow (Hibiscus moscheutos) Caused by a Novel Fusarium sp.

Abstract

A new crown and root rot disease of landscape plantings of the malvaceous ornamental common rose mallow (Hibiscus moscheutos) was first detected in Washington State in 2012. The main objectives of this study were to complete Koch’s postulates, document the disease symptoms photographically, and identify the causal agent using multilocus molecular phylogenetics. Results of the pathogenicity experiments demonstrated that the Fusarium sp. could induce vascular wilt and root and crown rot symptoms on H. moscheutos ‘Luna Rose’. Maximum-likelihood and maximum-parsimony phylogenetic analyses of portions of translation elongation factor 1-α and DNA-directed RNA polymerase II largest and second-largest subunit indicated that the Hibiscus pathogen represents a novel, undescribed Fusarium sp. nested within the Fusarium buharicum species complex.