Link to home

Geographic Distribution and rDNA-ITS Region Sequence Diversity of Waitea circinata var. circinata Isolated from Annual Bluegrass in the United States

September 2009 , Volume 93 , Number  9
Pages  906 - 911

Chi-Min Chen and Karla A. de la Cerda, Department of Plant Pathology, University of California, Riverside 92521; John E. Kaminski, Department of Plant Science, University of Connecticut, Storrs 06269; and Greg W. Douhan and Francis P. Wong, Department of Plant Pathology, University of California, Riverside 92521



Go to article:
Accepted for publication 29 April 2009.
ABSTRACT

Waitea circinata var. circinata is the causal agent of brown ring patch, an emergent disease of turfgrass in the United States. Forty-two isolates from annual bluegrass were obtained from California, Connecticut, Idaho, Illinois, Massachusetts, New York, Ohio, Oregon, and Rhode Island. Almost all isolates produced white to orange sclerotia (bulbils), 2 to 5 mm in size, that turned dark brown after 21 days on ¼-strength potato dextrose agar. The ribosomal DNA internal transcribed spacer regions and 5.8S region (ITS) were analyzed by restriction fragment length polymorphism (RFLP) analysis using MspI and sequencing to attempt identification of the isolates. Some isolates were heterozygous at the MspI restriction site, results not found in previous reports using the RFLP technique for identification. Four additional nucleotide positions were found to be variable within ITS based on sequence analysis, including two indels and two additional heterozygous positions. A total of 17 ITS haplotypes were found, and there was no obvious relationship between ITS haplotype and the geographic distribution of the isolates. Results of this work indicate that W. circinata var. circinata is present in multiple states and provide an initial understanding of the diversity of the pathogen in the United States.



© 2009 The American Phytopathological Society