Development and characterization of microsatellite markers for Sclerotinia homoeocarpa
A. I. PUTMAN (1), I. Carbone (1), L. P. Tredway (1)
(1) North Carolina State University, Raleigh, NC, U.S.A.
Phytopathology 101:S147

Sclerotinia homoeocarpa causes dollar spot, the most economically important disease of turfgrass worldwide. The objective of this research is to develop and use microsatellite markers in population studies of S. homoeocarpa. Microsatellites were initially isolated using a bead capture enrichment protocol, and additional repeats were identified in silico from an early draft genome assembly of S. homoeocarpa using the Tandem Repeat Database. Microsatellites with sufficient flanking sequence to the end of the read or to adjacent repeats were deemed suitable for primer design. Next, candidate loci were examined for polymorphisms by Sanger sequencing. Candidates containing indels in the flanking region or compound polymorphisms were discarded as not usable. From the genome data, 6,075 microsatellites were identified based on minimum thresholds of repeat number, copy number, and perfection of repeat units. Two of 31 candidate loci from the enrichment protocol were selected as usable. Of the 791 candidate loci identified in silico, to date 5 usable loci have been selected and 42 have been discarded. Two to four alleles per locus have been found among a select group of cool- and warm-season isolates from four continents. Multiplex PCR protocols using fluorescently-tagged universal primers are being developed to enable rapid genotyping. These microsatellites will be useful in determining the diversity and structure among worldwide populations of S. homoeocarpa.