Purification and Properties of Spherical Virus Particles Associated with Grapevine Ajinashika Disease. Shigetou Namba, Assistant Professor, Laboratory of Plant Pathology, Faculty of Agriculture, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan. Donato Boscia, Shuichi Yamashita, Tsuneo Tsuchizaki, and Dennis Gonsalves. Senior Researcher, Dipartimento di Patologia vegetale, Universitå degli Studi, 70126, Bari, Italy; Associate Professor, Professor, Laboratory of Plant Pathology, Faculty of Agriculture, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan; and Professor, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456. Plant Dis. 75:1249-1253. Accepted for publication 29 May 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-1249.

Grapevine ajinashika associated virus (GAaV) was successfully purified from ajinashika-affected berry pulps by an enzyme treatment purification procedure. Virions were spherical (approximately 25 nm in diameter), sedimented as a single component of approximately 110S, had a buoyant density in CsCl of approximately 1.38 g/cm³, and had an estimated nucleic acid content of 30%. GAaV contained a single species of single-stranded RNA of an estimated 6.8 kb and a coat protein of 23,000 Da. GAaV was effectively detected in extracts of shoots and mature berries by immunosorbent electron microscopy (IEM) and enzyme-linked immunosorbent assay (ELISA) using specific antiserum. Biological and physicochemical properties of GAaV were similar to luteoviruses. However, GAaV shared no serological relationships with barley yellow dwarf and potato leafroll viruses. Antisera of grapevine fanleaf virus and grapevine phloem-limited isometric virus (GPLIV) did not react with GAaV in IEM and double-diffusion tests. However, anti-GPLIV antiserum reacted with GAaV in protein A-gold labelling immunosorbent electron microscopy.