Sclerotinia homoeocarpa is a common and severe fungal
pathogen
responsible for dollar spot disease on turfgrasses. The RAPD–PCR
technique was used to identify genetic variation among 26 isolates of S.
homoeocarpa. DNA polymorphisms were detected among
different isolates using 15 oligonucleotide primers and a dendrogram was
constructed using the unweighted pair-group method with
arithmetic averages (UPGMA) for cluster analysis. Isolates from different
geographical locations in the United States were separable
into three distinct groups based on RAPD profiles and the cluster analysis.
These three groups, however, were clearly more closely
related to each other than to the isolate from Belize which was unique
compared to the other S. homoeocarpa isolates examined.
RAPD profiles suggest that transport of the pathogen from east coast to
west
coast locations in the U.S.A. may account for the
recent identification of the disease in the Pacific Northwest. The results
indicate that RAPD–PCR is a valuable method for
differentiating isolates of S. homoeocarpa.