Arundo donax, a perennial grass, is being considered as a renewable-fuel feedstock. A. donax reproduces vegetatively and can produce over 30 Mg ha(-1) of biomass, making it an ideal candidate for biofuel. There is limited information on the susceptibility of A. donax to pests and pathogens and the implications for biofuel production. This study examined the ability of Barley yellow dwarf virus (BYDV-PAV) to infect A. donax under controlled conditions using the aphid vector Rhopalosiphum padi, and the impact of BYDV-PAV on A. donax growth. Virus systemicity and the potential for A. donax to serve as a BYDV-PAV inoculum source were also examined. Immunological techniques confirmed BYDV-PAV infection of A. donax, but there were no significant differences in height, number of leaves and number of shoots per rhizome between infected and healthy plants, suggesting A. donax is tolerant to BYDV-PAV. BYDV-PAV infection was determined to be systemic within the host, resulting in virus detection in multiple shoots of the same rhizome. Transmission from infected A. donax to susceptible barley plants was demonstrated using the vector R. padi. These results demonstrate that A. donax is an alternative host to BYDV-PAV. Large A. donax monocultures may provide a perennial inoculum source to neighboring small grain crops, like wheat and barley, as well as turf and forage grasses. Field studies are needed to examine the movement of insect vectors between A. donax, susceptible crops and non-managed ecosystems to assess the ecological and epidemiological implications of these findings. (c) 2014 Elsevier Ltd. All rights reserved.