Multilocus sequence analysis of Sclerotinia homoeocarpa populations from turfgrasses

• Published in: Phytopathology 2009-06, Vol.99 (6), p.S127-S127
• Main Authors: Taylor, T A, Carbone, I, Tredway, L P
• Format: Article
• Language: English
• Subjects: Sclerotinia homoeocarpa
• ISSN: 0031-949X

Sclerotinia homoeocarpa is the fungal pathogen responsible for dollar spot disease on turfgrasses. This pathogen infects all turf species and is found worldwide. Sclerotinia homoeocarpa was first described by F.T. Bennett in 1937. Bennett described the fungus as producing both apothecia and sclerotial structures, both of which are not seen today. This has resulted in a scientific debate where most believe the fungus belongs to the family Rutstroemiaceae due to the production of substratal stromata. Isolates of S. homoeocarpa were obtained from turfgrass species collected in the United States, Europe and Asia. Four loci (ITS, beta-tubulin, Elongation Factor, and Calmodulin) were amplified using PCR and then sequenced via cycle sequencing. Isolates of S. sclerotiorum, Rutstroemia paludosa and R. cuniculi were also included for comparison. All isolates analyzed thus far are distinct from S. homoeocarpa type-isolates described by Bennett in 1937. The results obtained to date indicate that genetic diversity among isolates is dependent on host species rather than geographic location, with isolates from warm- and cool-season turfgrasses separating into distinct clades. Host species is clearly a major factor that determines genetic diversity in populations of S. homoeocarpa causing dollar spot in turfgrasses. Additional methods such as mitochondrial gene analysis or microsatellites are needed to provide further resolution into the genetic diversity of S. homoeocarpa.