Multiple Species of Asteraceae Plants Are Susceptible to Root Infection by the Necrotrophic Fungal Pathogen .

The necrotrophic fungal pathogen can cause disease on numerous plant species, including many important crops. Most -incited diseases of crop plants are initiated by airborne ascospores produced when fungal sclerotia germinate to form spore-bearing apothecia. However, basal stalk rot of sunflower occurs when sclerotia germinate to form mycelia within the soil, which subsequently invade sunflower roots. To determine whether other plant species in the Asteraceae family are susceptible to root infection by , cultivated sunflower ( L.) and seven other Asteraceae species were evaluated for root infection by inoculation with either sclerotia or mycelial inoculum. Additionally, root susceptibility of sunflower was compared with that of dry edible bean and canola, two plant species susceptible to but not known to display root-initiated infections. Results indicated that multiple Asteraceae family plants are susceptible to root infection after inoculation with either sclerotia or mycelium. These observations expand the range of plant hosts susceptible to root infection, elucidate differences in root inoculation methodology, and emphasize the importance of soilborne infection to Asteraceae crop and weed species.