Location: Floral and Nursery Plants ResearchTitle: PCR-based detection of the epibiotic fungus Atkinsonella hypoxylon within its host grass Danthonia spicata
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2020
Publication Date: 6/8/2020
Citation: Warnke, S.E. 2020. PCR-based detection of the epibiotic fungus Atkinsonella hypoxylon within its host grass Danthonia spicata. Crop Science. 60:1660-1665. https://doi.org/10.1002/csc2.20149.
Interpretive Summary: Poverty oatgrass is a perennial bunch-type grass native to North America. It is managed as a turfgrass in areas of the United States where cool-season grasses are adapted, and it has potential for development as a low-input turfgrass option. However, poverty oatgrass plants are occasionally infected with a fungus that can affect seed production. An ARS scientist in Beltsville, MD developed an assay that can specifically detect and identify the fungus growing outside and within plants of poverty oatgrass. The test revealed that this fungus was present in all 24 of the sample seed heads tested so far. The results suggest that all poverty oatgrass plants may have the fungus present, but it only affects seed yield occasionally. The results will help to understand the interaction between the fungus and poverty oatgrass to enable more effective use of this grass as a turf option.
Technical Abstract: Danthonia spicata (L.) Beauv., commonly known as poverty oatgrass, is a perennial bunch-type grass native to North America. D. spicata is often managed as a turfgrass in areas of the United States where cool-season grasses are adapted and has potential for development as a low-input turfgrass option. Naturally occurring D. spicata occasionally exhibit “choke” of the flowering stems due to a proliferation of fungal hyphae by the ascomycete Atkinsonella hypoxylon (Peck) Diehl. (family Clavicipitaceae). PCR primers were designed to amplify a 116 base pair A. hypoxylon specific fragment within the 5.8s rRNA Internal Transcribed Spacer 1 region. The primer set was then used to amplify the fragment from 24 A. hypoxylon isolates and 24 D. spicata seedhead DNA extractions collected from a greenhouse-maintained population. The A. hypoxylon ITS-1 fragment was amplified from all fungal samples and all seedhead samples tested. The ITS-1 fragment amplified from A. hypoxylon fungal isolates can be used to separate the isolates into two groups. The plant and fungal amplified fragments produced the same melt peak in High Resolution Melt analysis (HRM) and sequence analysis of the 24 seedhead amplified fragments all showed highly significant blast hits with the ITS 1 sequence of A. hypoxylon GenBank accession U57405.1 and the 24 A. hypoxylon isolates. These results provide evidence that all D. spicata plants contain the fungus A. hypoxylon and provides a useful tool to study A. hypoxylon and its association with D. spicata.