ARS | Publication request: DEVELOPMENT OF SIMPLE SEQUENCE REPEAT MARKERS FOR THE PLANT PATHOGENIC RUST FUNGUS, PUCCINIA GRAMINIS

Submitted to: Molecular Ecology Notes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 25, 2006
Publication Date: January 1, 2007
Citation: Szabo, L.J. 2007. Development of Simple Sequence Repeat Markers for the Plant Pathogenic Rust Fungus, Puccinia graminis. Molecular Ecology Notes. 7:92-94.

Interpretive Summary: Stem rust is a common and economically important disease of cereals (wheat, barely, oat and rye) and turf grasses. In order to better understand the population structure of this fungal pathogen genotypic markers were needed. A set of 24 specific markers was developed and used to analyze a test population of 25 isolates of the wheat stem rust fungus from around the world. These results demonstrated that these 24 markers were polymorphic and able to be used for genetic fingerprinting of races of the wheat stem rust fungus. In addition, these markers are specific to stem rust and therefore are useful for direct analysis of samples from infected leaf tissue eliminating the need to purify the fungus prior to analysis. This work provides scientists with the first set of molecular markers for genetic fingerprinting stem rust fungal isolates.

Technical Abstract: Twenty-four dinucleotide simple sequence repeat markers were developed for the phytopathogenic fungus, Puccinia graminis. The identified loci were polymorphic, with allelic diversity ranging from 2 to 11 alleles. Levels of heterozygosity ranged from 0.000 to 0.960 and 0.113 to 0.846 for observed and expected, respectively. Fourteen of the loci deviated significantly from Hardy-Weinberg equilibrium. Null alleles were observed for 10 of the 24 loci with a frequency of 4 to 16%. A preliminary screen of other cereal rust fungi (P. coronata, P. striiformis and P. triticina) indicated that these primer pairs are specific to P. graminis.