Random Amplified Polymorphic DNA Analysis of Japanese Isolates of Verticillium dahliae and V. albo-atrum . Masanori Koike, Assistant Professor; Department of Agro-environmental Science, Obihiro University of Agriculture & Veterinary Medicine, Obihiro, Hokkaido 080, Japan. Mitsuteru Fujita, Undergraduate Student, Department of Agro-environmental Science, Obihiro University of Agriculture & Veterinary Medicine, Obihiro, Hokkaido 080, Japan; Hideyuki Nagao, Assistant Professor, Laboratory of Plant Pathology, Faculty of Horticulture, Chiba University, Matsudo, Chiba, Japan; and Satoko Ohshima, Phytopathotogist, Kimitsu Breeding Station, Sakata Seed Corp., Sodegaura, Chiba 299-02, Japan. Plant Dis. 80:1224-1227. Accepted for publication 24 June 1996. Copy right 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-1224.

Japanese isolates of Verticillium dahliae and V. albo-atrum have been differentiated into four and two pathogenicity groups, respectively. Japanese isolates, 29 isolates of V. dahliae and 15 isolates of V. albo-atrum, representing different pathogenicity groups were analyzed by means of the random amplified polymorphic DNA (RAPD) method using polymerase chain reaction (PCR). V dahliae could be differentiated into three subclusters and V. albo-atrum into two sub-clusters. In V. dahliae, the first subcluster (RAPD type I) included isolates in group A (eggplant pathotype), group C (sweet pepper pathotype), and another group with pathogenicity not determined. The second subcluster (RAPD type II) included group B isolates (tomato pathotypes). The third subcluster (RAPD type III) contained four diploid isolates (group D, brassica pathotype) and one haploid isolate (84111). In V. albo-atrum, the isolates were divided into two sub-clusters. The first subcluster (RAPD type IV) included isolates in only the alfalfa pathotype. The second subcluster (RAPD V) included one alfalfa pathotype isolate (Vaa-s02), three potato pathotype isolates, and three undetermined pathotype isolates from alfalfa. Similarities and differences in banding patterns obtained by RAPD could be a useful molecular tool in identification and phylogenetic studies of the pathogenicity groups.