VIEW ARTICLE

Ecology and Epidemiology

Separation by Protein Electrophoresis of Six Species of Phytophthora Associated with Deciduous Fruit Crops. Anna Bielenin, Department of Botany and Plant Pathology and the Pesticide Research Center, Michigan State University, East Lansing 48824, and the Institute of Pomology and Floriculture, 96-100 Skierniewice, Poland; S. N. Jeffers(2), W. F. Wilcox(3), and A. L. Jones(4). (2)Department of Plant Pathology, University of Wisconsin, Madison 53706; (3)Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456; (4)Department of Botany and Plant Pathology and the Pesticide Research Center, Michigan State University, East Lansing 48824. Phytopathology 78:1402-1408. Accepted for publication 23 June 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/Phyto-78-1402.

Polyacrylamide gel electrophoresis was employed to compare the patterns of native and sodium dodecyl sulfate dissociated proteins obtained from mycelia of six species of Phytophthora isolated primarily from deciduous fruit crops grown in the Great Lakes states. The intraspecific variation in banding patterns among isolates identified as P. cactorum, P. cambivora, and P. syringae was less than that among isolates identified as P. megasperma, P. cryptogea, and P. drechsleri. When native proteins were analyzed, the number of distinct subgroups distinguished were two in P. cactorum, two in P. syringae, one in P. cambivora, two in P. drechsleri, three in P. cryptogea, and six in P. megasperma. When dissociated proteins were analyzed, P. cactorum, P. syringae, and P. cambivora each formed single, distinct groups; P. cryptogea and P. drechsleri each formed two subgroups, one of which was common to isolates of both species. Most isolates of P. megasperma from deciduous fruit crops, when compared with isolates representing the six protein subgroups previously established for isolates of P. megasperma, had protein patterns belonging to the “broad host range” group, whereas the remaining few belonged to the “apple, cherry, apricot” group. The results obtained with electrophoresis support the use of this approach as an aid in distinguishing the species and subgroups within species of Phytophthora encountered on deciduous fruit crops.