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ARS Home » Pacific West Area » Corvallis, Oregon » National Clonal Germplasm Repository » Research » Publications at this Location » Publication #419575
Research Project: Conservation and Utilization of Temperate-Adapted Fruit, Nut, and Other Specialty Crop Genetic Resources

Location: National Clonal Germplasm Repository

Title: Strategies to develop and apply a test for detection of ringspot viruses in dagger nematodes in small fruits and grapevines

Author
item OLAYA, CRISTIAN - Orise Fellow
item Reinhold Aboosaie, Lauri
item Mollov, Dimitre
item Zasada, Inga

Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2023
Publication Date: 10/15/2023
Citation: Olaya, C., Reinhold Aboosaie, L.A., Mollov, D.S., Zasada, I.A. 2023. Strategies to develop and apply a test for detection of ringspot viruses in dagger nematodes in small fruits and grapevines. Journal of Nematology. e2023-1(55):84. https://doi.org/10.2478/jofnem-2023-0047.
DOI: https://doi.org/10.2478/jofnem-2023-0047

Interpretive Summary: Small fruits and grapevine are important commodities for the Pacific Northwest (PNW) of the United States. Tomato ringspot virus (ToRSV) and tobacco ringspot virus (TRSV) have been reported in the PNW as well as their vector, the dagger nematode. The presence of both virus and vector represents a risk factor for susceptible crops. Currently available diagnostic methods are not sensitive enough to detect low level infections. This research aims to develop testing methods capable of detecting ToRSV in individual nematodes.

Technical Abstract: Small fruits and grapevine are important commodities for the Pacific Northwest (PNW) of the United States. Tomato ringspot virus (ToRSV) and tobacco ringspot virus (TRSV) have been reported in the PNW as well as their vector, the dagger nematode (Xiphinema americanum sensu lato). The presence of both virus and vector represents a risk factor for susceptible crops. Currently available diagnostic methods are likely missing low titer infections or unknown ToRSV and TRSV variants. Also, lack of sensitivity makes it difficult to detect the viruses in the nematode. In this research we focused on ToRSV to develop a sensitive test to detect the virus in the dagger nematode. To achieve this goal, we first compiled a diverse collection of at least 33 ToRSV isolates for primer design; second, we surveyed small fruit crops in the PNW to determine the presence of the virus and the vector; third, we created a growth chamber protocol to produce dagger nematodes that harbor ToRSV. Available RT-qPCR assays detected 32 of 33 ToRSV isolates enabling the development of new primers for more comprehensive virus detection. Most of the samples collected in 2021 in the PNW tested negative for ToRSV. Only currants (Ribes spp.) tested positive for ToRSV. Dagger nematodes were found in 29% and 38% of samples collected in OR and WA from grapes and small fruit crops. When detected, population densities of dagger nematodes ranged from six to 451 per 250 g of soil. For the development of a protocol to produce nematodes that harbor ToRSV, cucumber plants were mechanically inoculated with ToRSV and exposed to at least 20 dagger nematodes. RNA from single nematodes will be isolated and tested for ToRSV. Preliminary results show that dagger nematodes are widespread on grapes and small fruits in the PNW and that there is a need for sensitive and comprehensive detection methods for ToRSV.