Mechanical transmission of maize rayado fino marafivirus (MRFV) to maize and barley by means of the vascular puncture technique

Maize rayado fino marafivirus (MRFV) was mechanically transmitted to kernel s of three Costa Rican maize cultivars by the vascular puncture technique. A transmission rate of up to 43.2% was obtained for cultivar HC-57. The rat e of MRFV transmission to maize was possibly affected by the morphology of the kernel, which may influence physical access to the vascular tissue afte r water imbibition. Transmission to maize was confirmed by western blot and immunosorbent electron microscopy. By slight modifications of the procedur e, MRFV was also transmitted to barley. This is the first report of MRFV in fecting a species outside the supertribe Andropogonodae. Virus infection an d replication in barley were confirmed by RT-PCR detection of MRFV RNA and by detection of the virus by ELISA.