The main focuses of the Plant Virology Unit at ARC-PHP is:

  1. Research on virus diseases affecting economically important crops like grapevine and citrus

  2. To provide a diagnostic service to industries and nurseries to assist them in certifying their propagation material as virus free.

The unit also keep the Plant Virus and Antiserum collection. Antisera raised against a wide range of plant viruses, and sero- reagents are used in routine ELISA and ISEM tests.

Diagnostic services

When it comes to virus control prevention is the only option. The ultimate goal in plant virus disease control is therefore to prevent virus spread by either controlling the vectors or through the eradication of infected plants. To protect the interest of farmers, the agricultural industry, as well as national and international trade, it is important that nurseries and tissue culture laboratories provide healthy virus free propagation material. Plants such as mother plants, seedlings and sometimes seed used as propagation material should be tested for viruses before it is supplied to farmers or other nurseries. The virus status of plants can only be established by expert diagnostic procedures, such as that offered by the Virology unit at ARC-PPRI.

ARC-PHP-Virology offer a plant virus diagnostic and indexing service to identify any plant virus on any plant provided that we have the tested and optimized diagnostic test in place for the specific virus. Specific tests such as Enzyme-linked Immunosorbent Assay (ELISA) and Polymerase Chain Reaction (PCR) are most commonly used but Electron microscopy (EM) testing is also available. EM testing is used as a non-specific test to confirm the presence of a virus if no specific test is in place for that particular virus. Currently ARC-PPRI provides a number of routine virus tests on a number of different crops. Crops that are tested weekly are bananas (Musa sp.) tested for Cucumber Mosaic Virus (CMV), peppers (Capsicum sp.) tested for Pepper Mild Mottle Virus (PMMoV) and tobacco (Nicotiana sp.) tested for Tobacco Mosaic Virus (TMV), all being serious threat to agriculture. The routine virus indexings for these viruses are undertakenweekly throughout the year. Plants testing positive can be eliminated and not used for further propagation or for seed production. This indexing is an important, contribution towards the elimination of potential threats.  Contact person: Marika van der Merwe 

Research projects

Serore agents


Symptoms on peppadews

Personnel and their expertise

Dariusz.pngDariusz Goszczynski
Qualification: PhD (Warsaw, Poland)
Research Focus: Investigation of viral aetiology of Shiraz disease, Shiraz decline and Corky bark disease on grapevine
Marika.pngMarika van der Merwe
Qualification: BSc (UP)
Research Focus: Virus diagnostics
Ronel.png​Ronel Roberts
Qualification: MSc (UP)
Research Focus:
Epidemiology of Candidatus Liberibacter africanus
Nicole.pngNicola Robbertse
Qualification: MSc in Entomology (UP)
Research Focus:
Banana bunchy top virus - distribution and vector transmission

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