Viruses Associated With Potato Diseases in the East and South of the Kingdom of Saudi Arabia

Samples from potato plants showing symptoms suggestive of viral etiology were collected at eight intervals starting Autumn 1989 and ending Spring 1991 from the eastern ( Hofuf ) and southern ( Najran ) of Saudi Arabia. Double diffusion test ( DDT ) in agar plates and ELISA were used to detect viruses in these samples. In each region, alfalfa mosaic virus ( AMV ), cucumber mosaic virus ( CMV ), potato virus S ( PVS ), potato virus X ( PVX ), potato virus Y ( PVY ), potato yellow dwarf virus ( PYDV ), tobacco mosaic virus ( TMV ), tobacco ring spot virus ( TRSV ), and tomato spotted wilt virus ( TSWV ) were detected. The percentage of virus detection varied within the region and between the regions with Najran sustaining higher incidence than Hofuf. In this survey PYDV was detected for the first time outside north American in a single sample from each region by DDT during Autumn 1989, the only season in which the occurrence of this virus in Saudi Arabia was investigated