Approved Method(s)
| Method | Detail | NAPIS Survey Method |
|---|---|---|
| Visual | Collect symptomatic plant material | 3031 - General Visual Observation |
Survey Recommendations
No specific signs are present.
Symptoms:
The severity and prevalence of symptoms vary based on the age of the plant at the time of infection. Infected young plants may present mild symptoms that are easily overlooked, especially in facilities where the virus is not highly present. Symptoms are frequently seen in the apical area of the plant.
Leaves exhibit a mild to severe chlorotic (yellow) mosaic pattern, wrinkling, mottling (blotching), and occasional narrowing.
Infected tomato fruit exhibit yellow and brown discoloration, grooves, deformation, necrosis, and rugosity. The size and number of tomato fruit produced are reduced. In pepper, infected fruit display similar symptoms but can also show green grooves.
Infected green parts that attach fruits to the main stem (e.g., calyces, peduncles, sepals, and petioles) may also develop necrotic spots that can lead to premature fruit drop. Stems can also show signs of necrosis.
See the CAPS Pest Datasheet for images of symptoms.
- Wear gloves when collecting samples.
- Collect five to seven leaves for each sample. Take leaves from a single symptomatic plant and collect up to a maximum of five samples for each host variety, or a maximum of 10 samples total (Note: this applies only to symptomatic plants with multiple sets of true leaves).
- Invert a plastic resealable bag over your hand and use it to remove five to seven symptomatic young leaves from the plant. Seal leaves in the same bag.
- Visibly and indelibly flag or mark plants and areas sampled.
- Change gloves and disinfect any tools that may have touched the plant.
- Label the outside of each bag with the following:
- - A unique identification number and the date
- Collectors name
- A specific location in the greenhouse. - Remove the most symptomatic leaflet or entire leaf (for young plants) that is approximately 1 square inch in size (the size of a quarter) and place inside the mesh bag provided in the testing kit. If too much leaf material is used, the test can be inaccurate.
- Perform the ImmunoStrip test following the manufacturer"s instructions. Instructions for ImmunoStrip use can be found at: Agdia ImmunoStrip How To. If the control line does not appear on the ImmunoStrip:
- Make sure there are no bubbles or frothing inside the mesh bag; flick the bag to break any bubbles.
- Reuse the same bag containing buffer and plant material and test again with a new ImmunoStrip.
- Confirm that the control line is present on the new ImmunoStrip.
- If the control line fails to appear on a second ImmunoStrip, select another leaf and repeat testing using a fresh kit.
- If the ImmunoStrip indicates:
- - Negative result (no positive line appears) - Take no further action. Discard the remainder of the plant material using the facility"s regular methods for disposal.
- Positive result - Remaining tissue from presumptive positive samples must be sent to PPQ for confirmatory testing. Follow steps below under "Preparing Samples for Shipment to PPCDL"
- Fill out PPQ Form 391 for each sample.
Place up to 10 individual bags (1 bag = 1 sample) into a larger, one-gallon plastic resealable bag. - Place a hard copy of each completed PPQ Form 391 inside the outer one-gallon plastic bag. Each PPQ Form 391 should include the corresponding identification numbers for the individual bags.
- Keep plant tissue refrigerated until shipment; do not freeze samples. Send samples as soon as possible.
- Place samples into a heavy Styrofoam container with ice packs. Do not place the samples directly on the ice packs. Use newspaper or other materials to prevent direct contact.
- Seal all seams of the shipping container with shipping tape.
- Prior to shipping samples, submitters must create a record for the submission in the Agricultural Risk Management (ARM) system. Submitters must also contact the PPQ Plant Pathogen Confirmatory Diagnostics Lab (PPCDL) and the Domestic Diagnostic Coordinator by email:
APHIS-PPQCPHSTBeltsvilleSampleDiagnostics@usda.gov; PPQ.Diagnostic.Coordinator@usda.govIn the email, include:
a. Courier tracking number
b. Number of samples being shipped
c. ARM-generated diagnostic record (DR) number
d. Copy of the PPQ Form 391 - Ship via overnight express courier (FedEx, UPS, etc.) Monday through Thursday to PPQ"s PPCDL at:Sample Diagnostics
Attn: John Bienapfl or Ben Adducci
USDA-APHIS-PPQ-S&T PPCDL 9901 Powder Mill Road, Building 580
Laurel, MD 20708
Phone: (301) 313-9208 or (301) 313-9271
Approved Method(s)
The approved method for confirmation is Molecular.
If symptomatic plant material is seen, screen samples onsite using TMV Immunostrips. Alternatively, symptomatic material can be submitted to the authorized diagnostician used by the State for screening. All samples testing positive during screening must be forwarded to the PPQ Beltsville laboratory for confirmatory testing.
Guidance for conducting an immunostrip test can be found in the ImmunoStrip User Guide.
If you are unable to find a reference, contact STCAPS@usda.gov. See the CAPS Pest Datasheet for all references.