Improved Procedure for the Isolation of Double Stranded Rna from Virus-infected Grapevine

Introduction The presence of double stranded RNA (dsRNA) in virus-infected tissue has been well documented by Morris and Dodds (4), Dodds and Bar-Joseph (2). The analysis of dsRNA proved to be useful for determining the virus-free status of propagation material after sanitation treatments. Isolated directly from grapevine, dsRNA is also a good source of viral RNA for synthesizing and cloning cDNA from non-mechanically-transmitted closteroviruses (3). Isolation and purification of dsRNA from grapevine tissue, however, is problematic. Relatively large amounts of tissue are needed and the procedure is timeconsuming. The high concentration of polyphenols in grapevine tissue can also cause problems in the isolation of dsRNA. The objective of this study was to find a simplified procedure for the isolation of dsRNA from virus-infected grapevine that will yield enough dsRNA to produce detectable bands on a gel. The recovery of dsRNA was investigated during various phases of growth.