Evaluation of weeds as potential hosts of black foot and Petri disease pathogens on grapevine fields

Abstract

Weeds were sampled in grapevine rootstock mother fields, openroot field nurseries and commercial vineyards in Spain between June 2009 and June 2010 and evaluated as potential hosts for black foot and Petri disease pathogens. Isolations were performed from the root system and internal xylem tissues for black foot and Petri disease pathogens, respectively. Cylindrocarpon macrodidymum was successfully isolated from the roots of fifteen families and twenty-six weed species. Regarding Petri disease pathogens, one isolate of Phaeomoniella chlamydospora was obtained from Convolvulus arvensis, and three isolates of Cadophora luteo-olivacea were obtained from Bidens subalternans, Plantago coronopus and Sonchus oleraceus. Pathogenicity tests showed that C. macrodidymum isolates obtained from weeds were able to induce typical black foot disease symptoms and caused shoot and root mass reduction on grapevine seedlings. Isolates of Ca. luteo-olivacea and Pa. chlamydospora were also shown to be pathogenic on grapevine cuttings. These results indicate that weeds can serve as host for C. macrodidymum, Ca. luteo-olivacea and Pa. chlamydospora and may play roles in the epidemiology of black foot and Petri disease pathogens on grapevine.