A Polyacrylamide Gel Electrophoresis Index Method for Avocado Sunblotch. J. G. Utermohlen, Research Assistant, Department of Plant Pathology, Cooperative Extension, University of California, Riverside 92521. H. D. Ohr, Extension Plant Pathologist, Cooperative Extension, University of California, Riverside 92521. Plant Dis. 65:800-802. Accepted for publication 7 February 1981. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-800.

An index procedure for avocado sunblotch disease was developed with ribonucleic acid polyacrylamide gel electrophoresis. The gel index was 96% accurate in tests with known healthy and sunblotch-diseased trees (standard biological index). The assay takes 2 days to perform, compared with 3-24 mo for the standard biological index, and uses only 100–200 mg of host tissue.