Genetic Variation Of The Fungus Atkinsonella Hypoxylon Infecting Poverty Oat Grass

Poverty oat grass [Danthonia spicata (L.) P. Beauv. ex Roem. & Schult.] is a perennial bunch-type grass native to North America. Poverty oat grass is often present in managed turfgrass areas of the United States where cool-season grasses are adapted and has potential for development as a seeded low-input turfgrass option. Naturally occurring poverty oat grass plants occasionally exhibit choke on the flowering stems because of a proliferation of fungal hyphae by the ascomycete Atkinsonella hypoxylon (Peck) Diehl. (family Clavicipitaceae). Twenty-five A. hypoxylon isolates were cultured from choke-exhibiting poverty oat grass plants collected from five different populations. DNA variation was evaluated at the 5.8S ribosomal ribonucleic acid (rRNA) internal transcribed spacer (ITS) first (ITS-1) and second (ITS-2) regions and 10 simple sequence repeat (SSR) loci. Five single nucleotide polymorphisms (SNPs) in the ITS-1 region and an addition-deletion in the ITS-2 region identified two isolate groups present in four of the five populations. The 10 SSR loci exhibited 28 scorable alleles and support the two groupings with variation appearing as random mutations and high linkage disequilibrium providing no evidence for sexual recombination within or between the two identified groups.