title: Ten polymorphic microsatellite loci identified from a small insert genomic library for Peronospora tabacina.
abstract: Ten polymorphic microsatellite loci for the obligate biotrophic, oomycete pathogen of tobacco, Peronospora tabacina, were identified from a small insert genomic library enriched for GT motifs. Eighty-five percent of the 162 loci identified were composed of dinucleotide repeats, whereas only 4% and 11% were tri-and tetra-nucleotide repeats respectively. About 82% of all the microsatellites were perfect and within the library; only about 7% of the loci were duplicated. Primers were designed for 63 loci; 10 loci were polymorphic, 19 were monomorphic and 34 either failed to amplify or produced ambiguous/inconsistent results. The 10 polymorphic loci were characterized with 44 isolates of P. tabacina collected from tobacco plants growing in Europe, the Near East and North and South America. The number of alleles per locus was either three or four with a mean of 3.2, and the mean number of genotypes per locus was 3.6. Observed heterozygosity was 0.32-0.95, whereas expected heterozygosity was 0.44-0.69 for these loci. All loci except PT054 did not conform to the Hardy-Weinberg distribution. Polymorphic information content (PIC) for the loci was 0.35-0.69 with a mean of 0.50. These microsatellite loci provide a set of markers sufficient to perform genetic diversity and population studies of P. tabacina, and possibly other species of Peronospora.
authors.affiliation: Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996-4560, USA. rtrigian@utk.edu
authors.forename: Robert N
authors.initials: RN
authors.lastname: Trigiano
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Wadl
authors.forename: Deborah
authors.initials: D
authors.lastname: Dean
authors.forename: Denita
authors.initials: D
authors.lastname: Hadziabdic
authors.forename: Brian E
authors.initials: BE
authors.lastname: Scheffler
authors.forename: Fabian
authors.initials: F
authors.lastname: Runge
authors.forename: Sabine
authors.initials: S
authors.lastname: Telle
authors.forename: Marco
authors.initials: M
authors.lastname: Thines
authors.forename: Jean
authors.initials: J
authors.lastname: Ristaino
authors.forename: Otmar
authors.initials: O
authors.lastname: Spring
mesh_terms: D000483:Alleles; D017931:DNA Primers / Q000235:genetics; D018900:Dinucleotide Repeats; D056426:Genetic Loci / Q000235:genetics; D015698:Genomic Library; D005838:Genotype; D006579:Heterozygote; D018895:Microsatellite Repeats / Q000235:genetics*; D044742:Peronospora / Q000235:genetics*; D010935:Plant Diseases / Q000469:parasitology; D011110:Polymorphism, Genetic / Q000235:genetics*; D014026:Nicotiana / Q000469:parasitology*
chemical_list: D017931:DNA Primers