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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #411511
Research Project: Optimizing and Stabilizing Economic and Ecological Sustainability of Pacific Northwest Seed Cropping Systems Under Current and Future Climate Conditions

Location: Forage Seed and Cereal Research Unit

Title: Plant-parasitic nematodes associated with grasses grown for seed in the Willamette Valley of Oregon

Author
item Rivedal, Hannah
item Zasada, Inga
item Temple, Todd
item Peetz, Amy
item NUNEZ RODRIGUEZ, LESTER - Oregon State University
item STARCHVICK, ROBERT - Oregon State University
item BRAITHWAITE, EMILY - Oregon State University

Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2024
Publication Date: 5/10/2024
Citation: Rivedal, H.M., Zasada, I.A., Temple, T.N., Peetz, A.B., Nunez Rodriguez, L.A., Starchvick, R.J., Braithwaite, E.T. 2024. Plant-parasitic nematodes associated with grasses grown for seed in the Willamette Valley of Oregon. Journal of Nematology. 56:1. https://doi.org/10.2478/jofnem-2024-0020.
DOI: https://doi.org/10.2478/jofnem-2024-0020

Interpretive Summary: Plant-parasitic nematodes are soilborne pathogens of plants that have been understudied in the Oregon cool-season grass seed production system. This research aimed to identify the most prevalent plant-parasitic nematodes associated with annual ryegrass, bentgrass, fine fescue, orchardgrass, perennial ryegrass, and tall fescue seed fields in the Willamette Valley of Oregon. Plant-parasitic nematode communities were dominated by Pratylenchus and Meloidogyne species, with both genera exhibiting high populations across all grass hosts. Sequencing of barcoding genes identified five species of Pratylenchus and one species of Meloidogyne associated with Oregon grass seed crops. Statistical analysis showed marked plant-parasitic nematode communities across grass host and between spring and autumn sampling. This survey indicates the need for further research into the impact of plant-parasitic nematodes on cool-season grass seed crops.

Technical Abstract: Plant-parasitic nematodes are an understudied pathogen group in the Oregon cool-season grass seed cropping system. In this survey, the most prevalent plant-parasitic nematodes associated with annual ryegrass, bentgrass, fine fescue, orchardgrass, perennial ryegrass, and tall fescue were determined. Thirty-seven fields were sampled in the 2022 or 2023 growing season by collecting 10 soil cores in each of six 100-m transects for nematode extraction and visual identification. PerMANOVA testing indicated significant differences in plant-parasitic nematode community composition across grass host and sample timing. Pratylenchus and Meloidogyne were the most commonly encountered nematodes, with maximum population densities of 1,984 and 2,496 nematodes/100 g soil, respectively. Sequencing of the COX1 gene region indicated the presence of P. crenatus, P. fallax, P. neglectus, P. penetrans, and P. thornei, with some of these species being detected for the first time on these grass hosts. The only Meloidogyne sp. found in these grasses was M. nassi based upon sequencing of the ITS gene region. This first-of-its-kind survey indicates the need for further assessment of the impact of these plant-parasitic nematodes on yield and stand longevity in cool-season grass seed fields in Oregon.