Potato spindle tuber (PSTVd) - Pospiviroid Potato Spindle Tuber Viroid
Effective: May 11, 2022
Taxonomic Position: Unassigned : Pospiviroidae
Pest Type: Viruses
Pest Code (NAPIS): FVPSPTV
These Approved Methods are appropriate for: 2025, 2024, 2023
Pest Information
CAPS Pest Datasheet: https://download.ceris.purdue.edu/file/4331
Pest Tracker: https://pesttracker.org/pest/FVPSPTV
Hosts Identified in the CAPS Host Matrix:
Potato; Tomato
Pest is vectored by:
PTSVd can be transmitted through pollen exchange by insects. Vector transmission has been reported but not definitively confirmed.
Survey
Approved Method(s)
| Method | Detail | NAPIS Survey Method |
|---|---|---|
| Visual | Collect symptomatic plant material. | 3031 - General Visual Observation |
Survey Recommendations
The following are recommendations for executing the survey using the approved methods for pest surveillance. The recommendations are developed through literature review and consultation with subject matter experts.
Signs and Symptoms:
Potato symptoms include stunting, and small, elongated, cracked, and/or deformed tubers (Owens and Verhoeven, 2015).
Tomato symptoms include rugosity, bunching, stunting, chlorosis, necrotic flecks on underside of leaf veins (Harris and Browning, 1980), epinasty, lateral twisting of new leaflets, reduced fruit size (Hailstones et al., 2003), and a rough, puckered, dark green leaf texture (Ling et al., 2013).
Tomato symptoms include rugosity, bunching, stunting, chlorosis, necrotic flecks on underside of leaf veins (Harris and Browning, 1980), epinasty, lateral twisting of new leaflets, reduced fruit size (Hailstones et al., 2003), and a rough, puckered, dark green leaf texture (Ling et al., 2013).
Time of Year to Survey:
Survey during the growing season when symptoms are most likely to be visible.
Survey Site Selection:
Survey where hosts are present.
Key Diagnostic or Identification
Approved Method(s)
ID/Diagnostic:
This viroid can only be confirmed with molecular identification techniques.
Identification Resources:
The Identification Technology Program (ITP) has a collection of identification resources https://idtools.net/idAids/searchResults.cfm?searchString=potato+spindle+tuber+viroid&searchType=1
Mistaken Identities:
PTSVd can be mistaken for other plant pathogens or abiotic stress and can only be confirmed with molecular identification techniques.
To request a copy of diagnostic protocols, email the S&T Beltsville laboratory at APHIS-PPQCPHSTBeltsvilleSampleDiagnostics@aphis.usda.gov and use the subject line 'Diagnostic protocol request'.
References
If you are unable to find a reference, contact STCAPS@usda.gov. See the CAPS Pest Datasheet for all references.