Diagnostics

A key activity in the work of SASA is to develop and put into routine use, new and more sensitive diagnostic tests for pests and diseases. Such tests need to be rapid, simple to perform, lend themselves to automation and cheap. SASA has wide experience of developing and implementing such diagnostic tests into its work. These tests are generally based on serological approaches (Enzyme-linked immunosorbent assay (ELISA), immunofluorescence microscopy (IF), etc.) or molecular methods based around the detection of nucleic acids (polymerase chain reaction (PCR)).

SASA’s Monoclonal Antibody Unit, which was established in 1986, produces ELISA reagents for European and non-indigenous potato viruses selling to more than 17 countries around the World.

The Bacteriology Unit conducts tests mainly for quarantine and non-quarantine pathogens of potato using a range of tests based on PCR, IF, selective isolation and host testing.

Virology works mainly in support of the Scottish Seed Potato Classification Scheme and tests for a wide range of viruses using both ELISA and PCR.

Nematology tests around 20,000 soil samples each year for the presence of potato cyst nematode (PCN) using an automated soil washing system and a high-throughput real-time PCR tests which can differentiate between the two main species, Globodera rostochiensis and Globodera pallida.

Antibody Unit

The Antibody Unit was established in 1986 to enable SASA to meet its responsibilities for the health of Scottish seed potatoes and for the quarantine testing of imported potato material. The primary focus of this work has been the development of ELISA assays incorporating monoclonal antibodies (MAbs) for the detection of many indigenous and non-indigenous potato viruses.

Antibodies have been developed for use in testing imported potato breeding material, microplants of existing varieties, leaf samples from field grown plants and tubers. Antibody reagents may also be used in research applications such as Electron Microscopy, membrane blotting and immunocapture techniques for PCR.

Freeze dried conjugated antibodiesMost of the testing reagents we provide are based on MAbs produced in our tissue culture facility. Cell lines producing MAbs have all been developed at SASA and have undergone rigorous evaluation to ensure that the specificity that they exhibit is suitable for the testing systems required. In some cases defined mixtures of MAbs are used to ensure that the isolate range for a product covers the major geographical variants of the virus found in field situations.

*Freeze dried conjugated antibodies are also available on request where long-term storage is required or adverse shipping conditions may potentially affect liquid product.

New products are always under development.

Poster presentations relating to our products

Development of a Quality Assurance System for Plant Virus Testing Reagents  
Plant Virus Testing Reagents
Development of a Monoclonal Antibody for the detection of Potato Mop-Top Virus
SASA's Freezing

Reagent sets for ELISA testing contain two products, a coating antibody which is a purified form of the MAb used to trap virus to the wells of an ELISA plate and a reporter reagent which is the antibody conjugated to the enzyme alkaline phosphatase.

The antibody/enzyme conjugates are made by us using a controlled reaction process which optimises the ratios of antibody and enzyme.

Conjugates produced in this way exhibit high signal to noise ratios in ELISA and are extremely consistant in performance.

Reagents produced by us are tested for specificity and consistency and can be supplied with batch QC data.

BSI/UKASAll of the production steps in the manufacture of our antibodies and conjugates are controlled within a Quality Management system compliant to BSi EN 9001:2015 FM 59966

Current BSi certificate  

Antibody Sales

QUALITY SOLUTIONS TO YOUR TESTING REQUIREMENTS

SASA antibodies and ELISA reagents are produced under a quality system compliant to BS EN ISO 9001 2015. Accreditation to this standard was achieved in July 2001. All SASA antibodies have been extensively tested during development and all ELISA reagent sets can be supplied with Quality Control documentation.

SASA ELISA reagents, previously only available from our Scottish agent can now be purchased directly from us. Our comprehensive list of reagents for European and non-indigenous potato viruses is given below. Evaluation samples are available on request and special rates for bulk purchase may apply.

For all enquiries and to place an order contact:

Craig Douglas
Tel : +44 (0)131 244 8867
Email: Craig.Douglas@sasa.gsi.gov.uk

Orders are normally processed and dispatched on receipt of your request and we can usually arrange for next day delivery if this is required.

UK delivery by post is free of charge.

Courier charges are*

UK delivery £20.00
Europe £40.00
All other countries £50.00

*approximately depending on weights 

PRODUCT INFORMATION

Our reagents are available in 1000 and 5000 unit pack sizes for coating and conjugated antibodies. To simplify ordering our reagents are grouped into our Regular and Specialist lists. 

Antibody Product Brochure
Antibody Evaluation Form
Antibody Request Form
MSDS Antibody Reagents

Regular Products

Potato leafroll virus
Potato virus A
Potato virus M
Potato virus S 
Potato virus V
Potato virus X 
Potato virus Y o, c and n strains
Potato virus Y c strain
Potato virus Y o and c strains
Potato virus Y n strain

Coating antibody 1000 units = £85
Coating antibody 5000 units = £185

Conjugates 1000 units = £125
Conjugates 5000 units = £275

Specialist Products

Arracacha virus B - oca strain
Potato black ringspot virus including Tobacco ringspot virus - Calico strain
Potato latent virus (syn. Red la Soda virus)
Potato mop-top virus 
Potato virus T 
Tomato black ring virus

Coating antibody 1000 units = £125
Coating antibody 5000 units = £385

Conjugates 1000 units = £185
Conjugates 5000 units = £495

We maintain links with other agricultural institutes and many of our antibodies have been validated in a number of locations globally. All of our antibodies for the detection of Andean viruses have been tested at the International Potato Centre (CIP), Lima, Peru.

New products are always under development.

product information

Protocol (ELISA)

DAS ELISA Method

Prepare coating antibody in coating buffer at recommended dilution and dispense (200 μL) into wells of an ELISA plate.

Incubate 4hrs at 37oC.

Wash plate x4 with wash buffer and blot dry.

Prepare sample by homogenising plant material in extraction buffer 1/10 (w/v) and dispense (200 μL) into test wells. Incubate overnight at 4oC.

Wash plate x4 with wash buffer and blot dry.

Dilute antibody-AP conjugate at recommended dilution in extraction buffer and dispense (200 μL) into test wells. Incubate 2hrs 37oC.

Wash plate x4 with wash buffer and blot dry.

Prepare substrate 1mg/mL in substrate buffer and dispense (200 μL) into test wells. Incubate at ambient for 1-2hrs.

Read OD of test wells at 405n.

REAGENTS: Coating buffer, Wash buffer, Extraction buffer, Substrate buffer

NB: The above protocol is used by us for the QC evaluations that are carried out by us on our reagents. Users have found that conditions and reagent volumes may be varied without substantially affecting the results obtained.

Buffer Recipes

DAS-ELISA Method

Prepare coating antibody (MAb) in coating buffer at recommended dilution and dispense (200 µL) into wells of an ELISA plate.

Incubate 4hrs at 37oC.

Wash plate x4 with wash buffer and blot dry.

Prepare sample by homogenising plant material in extraction buffer 1/10 (w/v) and dispense (200 µL) into test wells. Incubate overnight at 4oC.

Wash plate x4 with wash buffer and blot dry.

Dilute antibody-AP conjugate at recommended dilution in extraction buffer and dispense (200 µL) into test wells. Incubate 2hrs 37oC.

Wash plate x4 with wash buffer and blot dry.

Prepare substrate 1mg/mL in substrate buffer and dispense (200 µL) into test wells. Incubate at ambient for 1-2hrs.

Read OD of test wells at 405n.

Buffer Recipes

Coating buffer substance         Amount
Na2CO3                                         0.8g
NaHCO3                                        1.4g
1% NaN3                                       10mL
H2O                                               500mL
pH 9.6

Wash buffer
Phosphate Buffered Saline + 0.05% Tween 20

Extraction buffer substance     Amount
Polyvinyl pyrrolidone                      10g
Bovine serum albumin                    1g
1% NaN3                                        10mL
Wash buffer                                   500mL
pH 7.4

Substrate buffer substance      Amount
Diethanolamine                             48.5mL
1% Sodium azide                           10mL
H2O                                               500mL
pH 9.8

1mg p-nitrophenyl phosphate per mL substate buffer   

Printable version of ELISA Buffer Recipes

SAPS Project

 

Science & Plants for Schools: ELISA kit

 

Science & Plants for Schools (SAPS) supports teachers, technicians and students learning plant science, from primary through to post-16. SAPS have a particular focus on innovative and reliable practical protocols for secondary biology.

SAPS Elisa kit

In 1990 SAPS launched a schools ELISA kit for the detection of Botrytis cinerea and approached the Antibody Unit to see if we would be willing to take over responsibility for the production and supply of the kits directly to schools. We agreed and now supply schools throughout the UK and parts of Europe with this very successful kit. The antibody used in the kit was developed by Molly Dewey of Oxford University and the cell line was gifted by her for use in this project.

Schools and further education institutes order the kits directly from SASA and we also provide a helpdesk facility for any advice that may be required by teachers.

This school and further education ELISA practical kit is a recognised biology practical by organisations including, SQA and AQA and is used by students studying Advanced Higher Biology, A-level biology and equivalent courses. 

ELISA dilution

This ELISA practical kit provides sufficient reagents and equipment for five pairs of students to carry out the experiment. Technical guides and Student guides can be found below.  

The kit is usually available ex stock and costs £35 including postage (ex VAT).

SAPS - PDF files

Student Guide
Technical Guide
Checklist Component

Orders can be placed by:

Phone:   0131 244 8867
Email  :  Craig.Douglas@sasa.gsi.gov.uk
Post   :  Antibody Unit, SASA, Roddinglaw Road, Edinburgh, EH12 9FJ

 

Additional teaching notes and ideas for investigations are available from the Science & Plants for Schools (SAPS) website.

Bacteriology

SASA has a dedicated team of bacteriologists providing a range of services and conducting research and development projects on a wide range of bacterial plant pathogens.

Most of the Bacteriology Unit's work is focused on bacterial pathogens of potato, though pathogens of strawberry are also covered.

The provision of services are either in support of the Scottish Seed Potato Classification Scheme or as part of Scotland's statutory obligation to ensure it remains free of range of quarantine organisms, specifically Clavibacter michiganensis subsp. sepedonicus and Ralstonia solanacearum.

Services include:

  • Provisions of annual surveys of Scottish potatoes for Clavibacter michiganensis subsp. sepedonicus, Ralstonia solanacearum, and Dickeya spp..
  • Provision of annual surveys of Scottish rivers for Ralstonia solanacearum and Dickeya spp..
  • Scientific and technical advice to the Scottish Government on the control of bacterial plant pathogens.
  • Testing of nuclear stock material for a wide range of bacterial pathogens.
  • Diagnosis of diseased samples submitted by Agriculture and Rural Economy Directorate inspectors for the presence of bacterial diseases.
  • Advice and diagnostic support on bacterial pathogens to the potato industry and stakeholder bodies.

For further details please contact Karen Fraser on 0131 244 8894 or by email; or Gerry Saddler on 0131 244 8925 or by email.

In addition, a range of research and development projects are currently underway into bacterial pathogens of potato or have recently been concluded.

R&D work includes:

Additional information on the main bacterial pathogens we work on (Clavibacter michiganensis subsp. sepedonicus - potato ring rot; Ralstonia solanacearum - potato brown rot; Pectobacterium - Blackleg/soft rot; Dickeya - Top wilt/blackleg/soft rot) can be found using the links below.

Ring Rot

Ring rot is caused by the quarantine bacterium, Clavibacter michiganensis subsp. sepedonicus (Cms). It is a serious plant health threat to potato production in Northern Europe. Ring rot has never been found in Scottish potatoes.

Infected seed lots are the main source of disease spread and Cms can persist for long periods (> 2 years) on surfaces, which raises the prospect of contaminated machinery and storage containers serving as a means of infection.

Symptoms of Ring rotCms causes wilting and chlorosis, which starts at the leaf margins. As the disease progresses the plant can collapse. Tubers develop characteristic symptoms, similar to brown rot, where the vascular tissue becomes discolured eventually leading to collapse and rotting of the tuber.

Although in Europe, the economic damage caused by the disease directly, is low. The costs associated with rejection of the infected crop, clean-up measures on farm, loss of reputation etc. for the grower concerned can be very high.

Brown Rot

Potato brown rot is caused by the quarantine bacterium, Ralstonia solanacearum. R. solanacearum is a genetically diverse and geographically widespread plant pathogen. It has a wide host range and is a significant pathogen of potato, causing brown rot. Brown rot is caused by a distinct, closely-related, intraspecific group: race 3/biovar 2A, more recently referred to as phylotype IIB, sequevar 1 (IIB1). Symptoms of Brown rotIn Europe, infection of potato crops with brown rot primarily occurs through the movement of infected seed, though irrigation with contaminated surface water is also important. Brown rot has never been found in Scottish potatoes though the bacterium has been found previously in one Scottish river system, the River Tay, both in water samples and on its secondary host, bittersweet (Solanum dulcamara), growing on the river banks.

Although brown rot can cause wilting of the potato plant, it is unlikley under cooler Scottish conditions. Symptoms are more likley to manifest themselves in the tuber, where bacterial ooze is evident in the vascular ring, and as symptoms develop can lead to a brown discolouration, hence the name ‘brown rot’. In Europe the vast majority of postive findings are made by laboratory tests of asymptomatically infected tubers.

Pectobacterium

Pectobacterium atrosepticum (previously known as Erwinia carotovora subsp. atroseptica) is the cause of potato blackleg in Scotland. Although blackleg and the associated soft-rot of tubers in store can cause severe economic losses, it's occurrence and severity are dependant on environmental factors in the field (temperature, rainfall, poor drainage etc.), timing of harvest and seed storage conditions.

Blackleg affects the lower part of the stem, producing a brown/black rot accompanied by a distinctive smell, often accompanied by yellowing/curling of the leaves. In early and severe cases, plants may not emerge or are stunted, yellow and die quickly post-emergence. The disease is spread by infected seed tubers, which when planted can infect daughter tubers through the vascular system and can infect neighbouring plants through groundwater as infected tuber begin to decay. Decaying tubers can also infect healthy tubers at harvest or in store by direct and indirect contact.

Propensity of the top 30 varieties to Blackleg

Variety has a very important effect on the incidence of disease symptoms observed at classification inspections. The term ‘varietal propensity’ has been adopted to describe whether symptoms observed within a variety are above or below the average across the whole Scottish seed crop.  Propensity is expressed as (% of disease within crops of a specific variety) / (% of disease in crops of all varieties).  The propensity score also indicates by how much a variety is above or below average, and can therefore be used as an indication of how one variety may compare with another. 

The table below summarises varietal propensity information collected over two periods 2009-2016, as well as just for season 2016, using data on the incidence of blackleg symptoms observed at crop inspection  (see also attached spreadsheet). Data are presented for the top 30 varieties entered for classification within the SPCS in 2016; these top 30 varieties making up 77% of total SPCS area in 2016.  By taking the maximum value for blackleg incidence across all inspections for each crop and multiplying this by the area of the respective crop, a quantitative estimate of the infection can be made.  Thus a crop of 4ha with a 3% incidence of blackleg contains 0.12 ha of blackleg infection.  Values greater than 1 indicate that blackleg is more likely to be observed in that variety and values less than 1 indicate that symptoms are less likely to be observed.  The table also shows values which are significantly greater or less than 1 at the 0.05 confidence level.  The cells in the table are shaded in red when the propensity is significantly higher than expected (i.e. 1) and shaded in green when values are significantly lower than expected.  Values that are not significantly different from 1 are left clear.  Sample size has a marked effect on the likelihood of significant departures from 1, hence the 2009-16 column shows a greater number of statistically significant departures from 1 than does the column for 2016 by itself.  It should be noted for the variety Cara that there is a very high level of variation in the levels of blackleg observed in different crops, so although the propensity for this variety is high, it is not significantly so. 

The interpretation of these data should take into account that the management of blackleg, e.g. heavy roguing, will have an effect on the disease incidence observed during inspections.  However, with approximately 4,000 seed crops entered for classification each year, similar husbandry practices would need to be extended across a high proportion of crops to have a marked influence on propensity. 

AttachmentSize
File Blackleg Propensity 2009-1613.95 KB

Dickeya

Top wilt/ blackleg/ soft rot – Dickeya spp.

The genus Dickeya was previously known as Erwinia chrysanthemi. There are two significant potato pathogens within this genus currently affecting Europe; Dickeya dianthicola and ‘Dickeya solani’. D. dianthicola has never been found on Scottish potatoes. ‘D. solani’ emerged in Europe around 2005-2006. It is highly aggressive on potato, causing rapid wilting and blackleg-like symptoms across wide environmental conditions.

Preliminary research indicates that ‘D. solani’ may be significantly more aggressive than D. dianthicola and Pectobacterium atrosepticum.  The new species appears to be able to rapidly induce blackleg symptoms and also to rot developing progeny tubers, even when inoculum levels are low. Aggressiveness of the new Dickeya pathogen appears to further increase at higher temperatures so there are implications for increased importance of this pathogen in response to global warming.  As yet, there is little substantiated practical information on the biology of this strain in relation to its host range, its ability to survive, establish and spread in the environment or its behaviour on stored potato tubers.

'D. solani’ has only ever been found on small number of Scottish ware crops (15 in total, from 2009 & 2010), all of which were grown from non-Scottish seed.

For further information see the Dickeya solani - a threat to our potatoes page on the Scottish Government website.

Information on a range of measures to protect Scotland's ware growers against Dickeya, and a range of threats, can be found in the Defending your potato crop against disease leaflet.

View recent surveys.

DNA fingerprinting

Urgent potato DNA fingerprinting service - unavailable over the Christmas period. Please submit all urgent samples by 18/12/17. Normal service will resume on 8/1/18.

What is DNA fingerprinting?

DNA fingerprinting is widely applied to identify individuals in a range of different circumstances.  Similar technology has been developed, at SASA, as a tool to resolve potato variety issues.

At SASA a searchable database, containing DNA fingerprints of  approximately 1,000 potato varieties, has been created.  Providing a variety is in the Database, it can be used to identify potato varieties.

The test method is quick and accurate using any part of the potato plant e.g. tubers, leaf and some processed produce e.g. crisps, chip.

Cost

Non urgent samples
One sample (eg one tuber)................................................... £65 (+VAT)
Results will be generated within 4 weeks

Urgent sample
One sample......................................................................... £120 (+VAT)
Results will be generated within 5 working days from receipt of the sample. Please advise us prior to submitting samples if you require this service.

Submitting samples

Samples should be sent to:

  Potato Fingerprinting
  SASA, Roddinglaw Road, Edinburgh, EH12 9FJ

Samples should be sent with as much information as possible on the request form, and marked Urgent/Non-Urgent.

For further information please contact:

  Helen Ventisei
  Email: dnafingerprinting@sasa.gsi.gov.uk  | Tel: (+44) 0131-244-8921

  Alex Reid
  Email: Alex.Reid@sasa.gsi.gov.uk  |  Tel: (+44) 0131-244-8910

See also the potato genotyping page.

Entomology

SASA's small team of entomologists identify invertebrates and provide specialist advice in support of Scottish agriculture, horticulture and apiculture. The services provided by the team can be broken down into four main areas of function.

Providing identification and advice on aphid numbers in Scottish suction traps in support of the Scottish seed potato industry

Aphids are particularly important pests of potatoes as they spread viruses within crops, significantly reducing the yield and quality. We operate a network of four suction traps within Scotland, identifying aphids caught in these traps and providing a weekly analysis on numbers and virus risk during the seed potato growing season. Reports are available on SASA's web pages as soon as they are completed. We also offer weekly email reports to interested parties; please contact Fiona Highet if you would like to be included in the weekly email bulletin.

As we have over 40 years' of standardised data and specimens, our aphid dataset is also a useful tool for looking at invertebrate population dynamics and how they respond to environmental change. Our datasets are available for researchers, and are listed in several information gateways, such as the UK-EOF (environmental observation framework). If you would like to use our data or would like further information about the data we hold, please contact Jon Pickup.

Running an aphid monitoring programme in support of the seed potato classification scheme

The level of virus in a seed potato crop is an essential factor in the classification process. We aim to identify seed potato crops in which aphids have not been successfully controlled. Crops identified are subject to further tuber testing at the end of the growing season to ensure that they meet the strict criteria laid down by the Scottish seed potato classification system.

Providing identification and technical advice on non-native quarantine invertebrate pests

Citrus longhorn beetle (Anoplophora chinensis) on host plant - Japanese Maple (Acer palmatum)SASA's entomologists identify invertebrates suspected to be quarantine pests for SG plant health inspectors and in response to queries by members of the public. Where a non-native pest species is identified, we provide advice to prevent it's establishment and spread within Scotland. The public plays an important role in preventing the introduction and spread of non-native pests into Scotland and Europe. If you suspect you may have found a quarantine pest, please capture it in a sealed container and contact your local Scottish Government Agriculture and Rural Delivery Division Area Office or contact Fiona Highet for further advice.

For information on the Citrus Longhorn Beetle, see the Scottish Government website.

Honey Bee Health diagnosis and advice

SASA provides disease diagnosis and advice in support of Scottish honeybees. An important part of this role is the identification of notifiable pests and diseases, such as foulbrood diseases, Tropilaelaps mites and Small Hive Beetle (SHB). If you think you may have a notifiable pest or disease, please contact your local SG Area Office in the first instance to speak to a bee inspector.  For contact details see the Scottish Government website.

We also provide a Varroa testing service for Scottish beekeepers who are unsure if their colonies have this pest to ensure that they can start necessary treament to protect their bees. If you would like to send a hive insert or scraping sample to SASA for testing, please send it to the address below -

Bee Diseases, SASA, Roddinglaw Road, EH12 9FJ.

GM Diagnostics

Staff in SASA’s GM team provide analytical testing support for the GM Inspectorate by detecting genetically modified material using multi-element PCR screening and event-specific quantitative PCR tests. 

SASA is a full member of the European Network of GMO laboratories (ENGL) and is one of three UK National Reference Laboratories who assist the EU Community Reference Laboratory in testing and validating methods for detecting and identifying GMOs (under EC Regulation 1981/2006). Competence in GMO testing is also maintained by regular participation in European Union Reference Laboratory comparative trials and ISTA GMO Proficiency Ring Tests.

SASA offers a screening test to detect nearly all known genetic modifications in oilseed rape and maize using a set of 5 element/junction specific assays. This test is accredited to ISO17025. We can also offer other testing services, such as screening for GM potato or soya, or quantification of specific GMOs. 

Please either contact the GM inspectorate mailbox or phone the numbers given below to discuss your requirements. 

For enquiries concerning GM testing telephone Heather Owen 0131 244 6353 or Karen Pearson 0131 244 8854.

Find out more about the GM Inspectorate at SASA.

 

Potato Pathology

The Potato Pathology team at SASA carries out testing and research to support the Scottish potato industry. We work closely with Scottish growers to maintain the high health status of Scottish seed potatoes. Annual health monitoring of stock from all Scottish PBTC growers helps to ensure optimal quality at the very start of the multiplication process. 

Research

We carry out research to support the potato industry. Recent research has included identifying the causes of pit rot  and research in collaboration with growers and AHDB to find environmentally-friendly alternatives to peat that do not compromise the health or productivity of PBTC production.

Training

We provide training to Scottish Government Agricultural Officers in identification of potato diseases, pests and disorders. We also support their work with scientific advice and laboratory diagnosis of tuber and field samples. Training courses in Identification of Potato Diseases and Inspection Procedures are held annually for trade delegates (in association with the British Potato Trades Association). Please contact Dr Rosalind McHugh or call 0131 244 8931 for further information about training courses.

Potato Disease Testing

SASA has expertise in testing potato tubers for a range of fungal blemish diseases and rots. We provide a commercial testing service, prices start at £70 for identification of specific pathogens, such as those listed below (we recommend that you send at least 5 -10 tubers if possible) and can also provide other, bespoke, services including disease severity assessments.

Surface Diseases Rot Diseases
Helminthosporium solani (silver scurf)
Polyscytalum pustulans (skin spot)
Rhizoctonia solani (black scurf)
Spongospora subterranea (powdery scab)
Streptomyces scabies (common scab)
Alternaria spp. (early blight)
Botrytis cinerea (wet rot)
Cylindrocarpon destructans
Fusarium coeruleum (dry rot)
Fusarium avenaceum (dry rot)
Fusarium sulphureum (powdery dry rot)
Phoma foveata (gangrene)
Phoma exigua
Phoma eupyrena
Phytophthora erythroseptica (pink rot)
Phytophthora infestans (late blight)
Pythium ultimum (watery wound rot)

 

 

 

 

 

 

 

 

 

Please complete the [Diagnosis Request Form], should you require our services. For further information, or to discuss bespoke pathology services, please contact potpath@sasa.gsi.gov.uk or call Dr Rosalind McHugh (0131 244 8931).

 

 

Virus Testing

Potato-infecting viruses cause significant damage worldwide and represent a significant threat to seed potato industries. The incidence of virus in seed potatoes can have a significant impact on crop quality (both seed and ware). Virus can result in seed crops not meeting the official standard for a class (downgrading) or even for certification as seed potato (failed). The presence of virus in seed potato crops may also enable damaging spread of virus during the growing year. There are about 40 viruses infecting cultivated potatoes, some of them like Potato Leaf Roll Virus (PLRV) and Potato Viruses Y, A, V, S, M and X are distributed worldwide in potato-growing areas.  

Virus testing is carried out mainly in support of the Scottish Seed Potato Classification Scheme. In addition a service is provided in support of the wider seed potato industry in Scotland. Tests are carried out for the following viruses:

  • Potato Viruses Y, X, A, S, M, V,
  • Potato Leaf Roll Virus
  • Tomato Black Ring Virus
  • Potato Mop Top Virus; and
  • Tobacco Rattle Virus.
  Virology Lab
 

Services include:

  • Tests on samples submitted by Scottish Government Agriculture and Rural Delivery Division inspectors during the course of growing crop inspections
  • Postharvest tuber testing of stocks in which growers have failed to control aphids during the growing season
  • Regular surveys of selected stocks for quality control purposes to ensure that virus levels are well within EU marketing tolerances for basic seed
  • Postharvest tuber tests on samples destined for export to ensure that they conform to the requirements of importing countries
  • Diagnosis of virus symptoms in samples submitted growers and agricultural advisors.

The following test methods are employed:

  • ELISA (Enzyme linked immunosorbent assay)
  • Real-time PCR (Polymerase Chain reaction)
  • Bioassay

Download the current Virus Testing price list.

Research and development is carried out on improvement of test methods, and the epidemiology of virus diseases of potato: