NEW TECHNOLOGIES FOR THE DETECTION AND IDENTIFICATION OF PATHOGENS IN BULBOUS CROPS WITH IMMUNOLOGICAL AND MOLECULAR HYBRIDIZATION TECHNIQUES.
With the introduction of the ELISA technique about 9 years ago routine detection and identification of plant viruses in bulbous crops in the Netherlands became possible. At present over 700,000 samples of tulips, lilies and irises are tested annually by the Bulb Inspection Service using antisera produced by the Bulb Research Centre. In general, polyclonal antisera prepared against purified viruses are successfully used. However, less satisfying results are obtained: i. if different serotypes of a virus exist (e.g., tobacco rattle virus (TRV) in tulip), ii. if a virus is difficult to detect in a specific cultivar (e.g., tulip breaking virus (TBV) in bulbs of some lily cultivars), iii. if a virus is poorly immunogenic or can not be purified in a substantial amount. In addition, for the detection or identification of other plant pathogens (bacteria, fungi, nematodes), ELISA based on polyclonal antibodies in general fails due to cross-reactivity with non-pathogenic organisms and a low sensitivity with intact pathogens. In these instances other serological assays might be useful in combination with monoclonal antibodies to a pathogen-specific epitope. If pathogen-specific epitopes cannot be found or if they are absent or if transgenic plants are constructed which produce virus coat-proteins, serological methods may not be applied. In such cases molecular hybridization with specific DNA probes made by the Dept. of Biochemistry, University of Leiden, might be an alternative technique for identification and perhaps even for detection. In addition with cDNA clones genomic structures of pathogens will be deduced. This is useful for a further characterization of pathogens occurring in bulbs. In the present paper some aspects of our current work in this area will be discussed.
Boonekamp, P.M., Asjes, C.J., Derks, A.F.L.M., van Doorn, J., Franssen, J.M., Linde, P.C.G.v., Vlugt, C.I.M.v., Bol, J.F., van Gemen, B., Linthorst, H.J.M., Memelink, J. and van Schadewijk, A.R. (1990). NEW TECHNOLOGIES FOR THE DETECTION AND IDENTIFICATION OF PATHOGENS IN BULBOUS CROPS WITH IMMUNOLOGICAL AND MOLECULAR HYBRIDIZATION TECHNIQUES.. Acta Hortic. 266, 483-490