Alfalfa vein mottling virus, a novel potyvirid infecting Medicago sativa L.

Abstract

We have recently identified a novel virus detected in alfalfa seed material. The virus was tentatively named alfalfa-associated potyvirus 1, as its genomic fragments bore similarities with potyvirids. In this study, we obtained a complete genome sequence of the virus and classified it as a tentative species in the new genus, most closely related to the members of the genus Ipomovirus in the family Potyviridae. This assumption is based on the genome structure, phylogenetic relationships, transmission electron microscopy investigations and, in part, on serological cross-reactivity of the virus. We also demonstrated its mechanical transmission to the indicator plant Nicotiana benthamiana and to the natural host Medicago sativa, both of which developed characteristic symptoms therefore suggesting a pathogenic nature of the disease. Consistent with symptomatology, the virus was renamed to alfalfa vein mottling virus. A name Alvemovirus was proposed for the new genus in the family Potyviridae, of which alfalfa vein mottling virus is a tentative member.