Double-Stranded RNA Isolated From Grapevines Affected by Rupestris Stem Pitting Disease

¹ Department of Plant Pathology, Washington State University, Pullman WA 99164-6430
² Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331.

A survey of healthy and rupestris stem pitting (SP) diseased grapevines has been made for the presence of double-stranded RNA (dsRNA). Commercially important Pinot noir and Pinot gris clones from Oregon State University (OSU) were selected on the basis of virus disease indexing results. Double-stranded RNA was extracted from leaves and dormant cane phloem of mature grapevines, purified by column chromatography, and characterized by RNase digestion, lithium chloride precipitation, acridine orange staining, and agarose gel electrophoresis. The single dsRNA species observed that was unique to SP diseased vines was approximately 5.5 x 10⁶ daltons. All SP-diseased vines contained one or more species of dsRNA while virus-free tissues contained none. Antisera prepared against grapevine virus "A" and against grapevine "potyvirus-like virus" were used in preliminary enzyme linked immunosorbent assays and gel diffusion tests, but results were inconclusive. Uses of dsRNA analysis for detection of SP disease are discussed.

Key words: rupestris stem pitting, double-stranded RNA, Legno-riccio, grapevine virus "A", grapevine stem pitting, Pinot noir, virus-free

Submitted on April 20, 1990