Hibiscus moscheutos subsp. palustris, new host of Verticillium dahliae

In the last three years near the lake of Fondi (Latina, central Italy), severe symptoms of stunting and wilting were observed on some plants of Hibiscus moscheutos subsp. palustris. an ecologically relevant, very rare wild species producing appreciated beautiful flowers, recorded in Tuscany and Latium, and constituting important example of biodiversity in the marsh areas. The severity of the symptoms prompted more detailed investigations to understand the etiology of the disease. The results of our investigations, based on isolations from infected stems and artificial inoculations of healthy plants, demonstrated that the fungus Verticillium dahliae Kleb., that was consistently isolated from infected tissues, is the causal agent of the disease. To our knowledge, this is the first report of V. dahliae on H. moscheutos subsp. palustris. The pathogen is a polyphagus and ubiquitous fungus recorded in Italy from a wide range of plant species, including another hibiscus (Hibiscus cannabinus L.). Infection of H. moscheutos subsp. palustris could origiante from inoculum spreading from cultivated infected fields. In the province of Latina different susceptible vegetables and fruits trees are widely grown, so that superficial water could play an important role in the dissemination of V. dahliae towards the lake of Fondi.