The NAKTUINBOUW-laboratory supports the inspection activities at nurseries.
Considerable attention is also paid to testing of samples on request.
Over 1,000,000 samples per year of ornamental crops and tree-nursery plants are tested with ELISA for different viruses (75 in total). Indicator plants are used if necessary.
Until now, the only viroid we tested for is chrysanthemum stunt viroid; testing is by means of bi-directional electrophoresis.
Although a RT-PCR has recently been developed, it is not yet suitable for large-scale routine testing.
For detection of bacteria and fungi, methods vary from growing on (selective) nutrient media, microscopical examination, immunofluorescence (IF), immunofluorescence colony-staining (IFC), and electrophoresis, to pathogenicity tests.
Several methods based on PCR are under development, in co-operation with researchers of the Plant Protection Institute at Wageningen.
Relatively new are a test for the presence of microsclerotia of Verticillium dahliae in soil and another for the rapid detection of Agrobacterium tumefaciens in various crops.
Meristem culture is applied on a small scale, to obtain disease-free material of certain crops, e.g. alstroemeria, hydrangea, paeonia, raspberry, strawberry.
On request, the obtained disease-free plantlets can be stored in vitro: e.g., chrysanthemum and strawberry varieties.
Test for resistance not only cover resistance to virus and fungal diseases, but also resistance to insect damage (thrips, whitefly, leafminer). In recent years, samples for testing are coming from more European countries rather than only from the Netherlands.