Characterization of Sphaeropsis sapinea from the West Central United States by Means of Random Amplified Polymorphic DNA Marker Analysis. Glen R. Stanosz, Department of Plant Pathology, University of Wisconsin-Madison, Madison 53706. Denise R. Smith, and Mark A. Guthmiller, Department of Plant Pathology, University of Wisconsin-Madison, Madison 53706. Plant Dis. 80:1175-1178. Accepted for publication 2 July 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-1175.

Two morphotypes (A and B) of the conifer pathogen Sphaeropsis sapinea recently have been confirmed as distinct populations by analyses of random amplified polymorphic DNA (RAPD) markers. Because much of the research on Sphaeropsis shoot blight and canker has been conducted in the west central United States, a study was undertaken to determine the morphotype(s) of S. sapinea encountered in this region. RAPD markers were obtained for 42 isolates of S. sapinea collected in Iowa, Nebraska, Oklahoma, and South Dakota from Picea pungens, Pinus contorta, P. nigra, P. ponderosa, P. resinosa, P. sylvestris, and Pseudotsuga menziesii. Relationships among these isolates, and eight other previously characterized isolates, were determined by cluster analysis. All 42 west central region isolates were placed in a single group with the previously characterized A morphotype isolates. This result facilitates interpretation of past research in that region and extrapolation to other areas where the A morphotype of 5. sapinea is present.

Keyword(s): Diplodia pinea