Genetic variation among Australasian pathotypes of P. hordei using a PCR-fingerprinting technique

Abstract

Mark Assange Cuthbert

Two PCR-fingerprinting primers, (GACA)4 and M13, were tested across 22 pathotypes of Puccinia hordei Otth collected from Australasia over a 30 year period, to assess their usefulness in revealing genetic variability in this pathogen. Both primers revealed polymorphisms among the pathotypes, with (GACA)4 generating a higher level of polymorphism. Molecular analyses revealed evidence of clonality among the P. hordei pathotypes, supporting the hypothesis that some arose from mutational changes in the pathogenicity of a founding pathogen genotype. Evidence was also obtained of sexual recombination within P. hordei in Australia on the alternate host Ornithogalum umbellatum. This is the first study of genetic variation among Australasian pathotypes of P. hordei using a PCR-fingerprinting technique