Detection of European Isolates of Oat Mosaic Virus

Abstract

Oat mosaic virus (OMV) is a fungally-transmitted virus which causes yield losses in winter oats in five European countries. Detection of the virus has depended upon the recognition of transient symptoms or electron microscopy. Recent research has confirmed that the virus is a Bymovirus, yet OMV could not be reliably detected by the enzyme-linked immunosorbent assay (ELISA) using a range of antisera raised against other members of the genus. Therefore, a reverse transcription-polymerase chain reaction (RT-PCR) protocol was developed to specifically detect the virus. Using total RNA isolated from 16 field OMV isolates collected from throughout Europe, these primers were shown to reliably detect the virus in either one-step or two-step RT-PCR. The primers were specific and no PCR product was obtained with either Oat golden stripe virus (OGSV), which is frequently associated with OMV, or with other members of the Bymovirus genus. The two-step protocol was able to detect as little as 5 × 10−3μl (10ng) of total RNA isolated from an infected plant. Both protocols were as reliable as electron microscopy, but were more sensitive and were able to detect infection earlier than in mechanically-inoculated plants. However, this protocol did not detect three American isolates of the virus nor was amplification achieved using alternative primers raising the possibility that these isolates may represent a separate strain or virus. This protocol enables sensitive, rapid and reliable detection of OMV and will therefore assist management of the disease.