VIEW ARTICLE

Genetics

Confirmation of Two Distinct Populations of Sphaeropsis sapinea in the North Central United States Using RAPDs. Denise R. Smith, Department of Plant Pathology, University of Wisconsin-Madison, 1630 Linden Drive, Madison 53706; Glen R. Stanosz, Department of Plant Pathology, University of Wisconsin-Madison, 1630 Linden Drive, Madison 53706. Phytopathology 85:699-704. Accepted for publication 28 March 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/Phyto-85-699.

Sphaeropsis shoot blight and canker, caused by Sphaeropsis sapinea, occurs on coniferous hosts worldwide and has resulted in considerable damage in the north central United States. Differences in morphology among isolates from this region suggest the existence of two subgroups, referred to as A and B morphotypes. However, these morphological differences are not consistent. Random amplified polymorphic DNA markers (RAPDs) were obtained for 16 A and 16 B morphotype isolates of S. sapinea collected in Michigan, Minnesota, and Wisconsin from Pinus banksiana, P. nigra, P. resinosa, P. strobus, and P. sylvestris. Relationships among isolates were determined using both cluster analyses and parsimony methods. All analyses placed the A morphotype isolates in one group and the B morphotype isolates in another group. Accurate identification of isolate morphotype will be useful in future pathological studies. These techniques may also help resolve relationships among S. sapinea isolates from their numerous hosts throughout the world.