DOUBLE-STRANDED-RNA COMPRISING THE PUTATIVE AVOCADO VIRUS-1 HAS A HIGH-DEGREE OF SEQUENCE HOMOLOGY TO THE AVOCADO GENOME

The hypothesis that the double-stranded (ds) RNA isolated from avocado is indicative of infection by RNA plant viruses has never been proven . However, it has not been disproven and the different dsRNAs are stil l known as putative avocado viruses (AV) 1, 2 and 3. We have probed re striction fragments of avocado cellular DNA with cloned P-32-labelled AV1-specific cDNA and discovered that the dsRNA nucleotide sequences a re also present on plant DNA. Our evidence contradicts the hypothesis that viruses are responsible for the formation of the dsRNA species in avocado.