A SIMPLE PROCEDURE TO DETECT A DSRNA ASSOCIATED WITH GROUNDNUT ROSETTE

A low-molecular weight double-stranded (ds) RNA [900 base pairs (bp)] associated with groundnut rosette disease [presumably caused by groundnut rosette virus and groundnut rosette assistor virus] can be used as a diagnostic tool. A simple procedure has been developed that is rapid, reliable, and requires only standard electrophoresis equipment and ultraviolet light for detection of nucleic acid bands. Using this procedure, the dsRNA was detected only in groundnut [Arachis hypogaea] plants with green rosette of chlorotic rosette symptoms. It was not found in uninoculated groundnut plants, in symptomless groundnut plants with groundnut rosette assistor virus, or in groundnut plants infected with several other known groundnut viruses. In studies with northern blots of extracts from rosette-diseased and healthy plants, 5''-endlabeled dsRNA only hybridized to a 900 bp dsRNA from diseased plants. The 900 bp dsRNA was not infectious and its origin remains obscure.