PDC Services

Pest Diagnostic Clinic Tests

(Last updated September, 2009)

Additional Information on Services provided by Clinic:

Basic plant disease diagnosis

The plant material submitted will be inspected under a stereo/dissecting microscope. Symptomatic tissues may be incubated in a moist chamber to encourage fungal growth and/or plated on selective growth media. Fungi isolated on plates can then be identified, while bacteria isolated may be further processed for species identification using the Biolog microbial identification system. (Back to top.)

Turn around time = 15 business days

Tar spot on maple.	Fusarium solani isolated from wheat.

Viral, fungal and bacterial identification using ELISA

This method has been accredited under the Standards Council of Canada. Serological assays are used to detect and identify viral, fungal and bacterial species present in symptomatic tissues. The test can be performed within 24 hours of receiving the sample at the Clinic. (Back to top.)

ELISA plate - yellow wells indicate positive samples.

The following ELISA tests area available at the Clinic:

• Alfalfa MosaicVirus (AMV)
• Alstroemeria Mosaic Virus (AlMV)
• Barley Sripe Mosaic Virus (BSMV)
• Barley Yellow Dwarf Virus (strains: mav, sgv and pav)
• Cereal Yellow Dwarf Virus-rpv - formerly known as Barley Yellow Dwarf Virus-rpv (CYWV-rpv)
• Bean Pod Mottle Virus (BPMV)
• Blueberry Scorch Virus (BlScV)
• Cactus Virus X (CVX)
• Calibrachoa Mottle Virus (CbMV)
• Clavibacter michiganensis ss michiganensis (Cmm)
• Cucumber Green Mottle Mosaic Virus (CGMMV)
• Cucumber Mosaic Virus (CMV)
• Cymbidium Mosaic Virus (CymMV)
• Pantoea stewartii (Pstew) - formerly known as Erwinia stewartii (Es)
• Hosta Virus X (HsVX)
• Impatiens Necrotic Spot Virus (INSV)
• Iris Yellow Spot Virus (IYSV)
• Maize Dwarf Virus (MDMV)
• Melon Necrotic Spot Virus (MNSV)
• Odontoglossum Ringspot Virus (ORSV)
• Papaya Ringspot Virus (PRSV)
• Pepino Mosaic Virus (PepMV)
• Pepper Mild Mottle Virus (PMMoV)
• Plum Pox Virus (Sharka) (PPV)
• Poinsettia Mosaic Virus (PnMV)
• Potyviruses (Poty)
• Phytophthora species (Phyt)
• Ralstonia solanacearum (formerly called Pseudomonas solanacearum) (Rs)
• Raspberry Bushy Dwarf Virus (RBDV)
• Scrophularia Mottle Virus (ScrMV)
• Soil-borne Wheat Mosaic Virus (SBWMV)
• Soybean Mosaic Virus (SMV)
• Soybean Rust (SBR)
• Sugar Cane Mosaic Virus (SCMV)
• Tobacco Etch Virus (TEV)
• Tobacco Mosaic Virus (TMV)
• Tobacco Ringspot Virus (TRSV)
• Tobacco Streak Virus (TSV)
• Tomato Mosaic Virus (ToMV)
• Tomato Ringspot Virus (ToRSV)
• Tomato Spotted Wilt Virus (TSWV)
• Tomato Yellow Leaf Curl Virus (TYLCV)
• Wheat Spindle Streak Mosaic Virus (WSSMV)
• Wheat Streak Mosaic Virus (WSMV)
• Xanthomonas campestris pv pelargonii (Xcp)
• Zucchini Yellow Mosaic Virus (ZYMV)

Virus detection using transmission electron microscopy (TEM)

Sap from symptomatic tissues is checked for viral particles using transmission electron microscopy. This procedure confirms the presence of viruses in plant tissues. It can not identify the exact viral species. (Back to top.)

Turn around time = 15 business days

Transmission Electron Microscope picture of Tomato Mosaic Virus

Bacterial identification using Biolog®

Isolated bacteria can be identified to species with the Clinic's Biolog® microbial identification system. The Clinic also has access to the MIDI microbial identification system. (Back to top.)

Turn around time = 15 business days

The Biolog® Microbial identification System.	Biolog® plate with positive (purple) wells.

The Clinic's plant identifications are performed by retired Botany professor Prof. Jack Alex or the staff at the University of Guelph's herbarium. (Back to top.)

Turn around time = 7 business days

Insect identification

Insects are inspected under a dissecting/stereo microscope. Identifications are made by using reference materials and detailed taxonomic keys. As well, it may include a partial dissection of the specimen in order to obtain body parts that clearly identify an insect (especially true for immature/larval insects). (Back to top.)

Turn around time = 7 business days

Forest tent caterpillar	Stink bug	Carpenter ant

This method has been accredited under the Standards Council of Canada. The Clinic uses the Baerman pan method. The soil remains suspended in water for 7 days during which time the nematodes present diffuse into the water. They are then identified and counted. (Back to top.)

Turn around time = 8 days

Female Pratylenchus penetrans - Ulrich Zunke*	Female ring nematode (Criconemellasp.) - J.D Eisenback*

SCN cyst & egg count

This method has been accredited under the Standards Council of Canada. The cysts of the soybean cyst nematode (Heterodera sp.) and the live eggs contained in the cysts are counted. The turn around time for this procedure is about 4 working days. Cyst nematode species identification is also available using molecular based techniques (Contact Clinic for further information). (Back to top.)

Turn around time = 5 business days

Cysts on soybean roots - Ulrich Zunke*	Cyst with Eggs - Ulrich Zunke*

Nematode extraction from roots/plant tissues

A minimum of 10 grams of fresh roots are required for this test. Ideally the youngest, growing roots are preferred. Most often, root lesion (Pratylenchus sp.) and root knot (Meloidogyne sp.) nematodes are extracted with this procedure. (Back to top.)

The turnaround time is just over one week.

Root knot nematode damage	Root lesion nematode damage on strawberry root - Ulrich Zunke*	Foliar nematode damage on cone flower - J.D. Eisenback*

Pinewood nematode detection in wood

The wood is cut into small pieces and soaked in water for 24 hours. The water is then carefully filtered and nematodes observed by microscopy. (Back to top.)

Turn around time = 5 business days

Pinewood nematodes, Bursaphelenchus xyphilus in xylem - Manuel Mota*	Discoloured pinewood that may harbour pinewood nematodes - Manuel Mota*

Verticillium dahliae count

The soil is first air dried, suspended in water and then plated on selective growth media. The Clinic staff identifies and counts the number of Verticillium dahliae colonies present. Verticillium counts are completed mostly for soils in which solanaceous (potatoes, tomatoes, peppers, etc.) are grown and usually in conjunction with soil counts of plant pathogenic nematodes. (Back to top.)

Turn around time = 21 days

Verticillium dahliae colony (magnification 40x)

*©1997, 1999 J.D. Eisenbach & Ulrich Zunke, NemaPix, A Journal of Nematological Images, Vol. 1&2.