Location: Forage Seed and Cereal ResearchTitle: Identification of Anguina funesta from annual ryegrass (Lolium multiflorum) seed lots in Oregon) Author
Submitted to: Plant Health Progress
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/14/2012
Publication Date: 10/24/2012
Citation: Meng, S., Alderman, S.C., Fraley, C., Ludy, R., Sun, F., Osterbauer, N. 2012. Identification of Anguina funesta from annual ryegrass (Lolium multiflorum) seed lots in Oregon. Plant Health Progress. 10:1094. Interpretive Summary: Anguina species are internationally regulated plant pests quarantined by many countries. In 2010, 2011, and 2012, Anguina funesta was detected in 14, 10, and 4 seed lots respectively. This is the first report of A. funesta in the US. This will have a significant impact on the ryegrass seed industry, as ryegrass for seed exports will need to be tested for presence of A. funesta.
Technical Abstract: In 2010, seed galls containing Anguina sp. were isolated from 14 annual ryegrass (Lolium multiflorum) seed lots submitted for phytosanitary testing. To identify the species present, the ITS1 region of the ribosomal DNA of the nematodes from the seed lots was analyzed using a PCR-RFLP method (11). All nematodes produced a single 540 bp DNA amplicon, which was then digested with three restriction enzymes, HaeIII, HinfI, and TaqI. The resulting RFLP patterns matched those of A. funesta (11). To confirm these results, 525 bp of the DNA amplicon was analyzed by DNA sequencing and BLAST analysis, which verified the sequence was identical to A. funesta (Genbank Accession Nos. AF363095, AF363096, and AF363104). Because of A. funesta’s known association with Rathayibacter toxicus, a second PCR test (6) was conducted to determine if the bacterium was present in the seed lots. A 200 bp DNA amplicon was amplified from two seed galls, sequenced, and subjected to BLAST analysis. Analysis of the entire DNA sequence failed to identify the bacterium present, although testing by USDA APHIS verified the bacterium was not R. toxicus. This is the first report of A. funesta in the US; R. toxicus apparently is not associated with this detection.