Abstract
Efficient and accurate diagnostic assays are essential for the design and evaluation of control measures of the potato cyst nematodesGlobodera rostochiensis andG. pallida by means of resistance. The hybridoma technology and the polymerase chain reaction (PCR) offer in potential various possibilities to design such diagnostic tests for routine purposes. We set out to devise a refined advisory system based on biochemical assays by using the following stepwise approach.
In the early 80's a research program was started to develop an immunoassay to differentiate the two sibling species of potato cyst nematodes. Species specific monoclonal antibodies were raised against nematode proteins which are thermostable, abundant and homologous, and which enable reliable species identification using single eggs.
The second step to improve the management of virulence genes is aimed at discriminating groups of populations within a species (‘virulence groups’ or ‘pathotypes’). The concept is that the number of initial populations introduced from South America is limited and that numerous Dutch populations (‘secondary founders’) are closely related by descent. Biochemical characters revealed by two-dimensional gel electrophoresis (2-DGE) of polypeptides, PCR in combination with restriction enzyme digests and RAPD (Random amplified polymorphic DNA) will be used to delineate groups of populations. The final diagnostic assay will be based on PCR. One of the challenges will be to devise a manageable number of primers to recognize all distinct groups.
The third research line is aimed at developing a PCR assay based on the virulence genes themselves. Genetic studies showed that virulence inG. rostochiensis towards the H1 resistance gene is inherited at a single locus and is recessive to avirulence. To identify molecular markers linked to the virulence gene, 300 virulent lines were selected via backcrossing the F1 (Aa) with the virulent (aa) parent line. Molecular differences between the parent lines were obtained by 2-DGE, RFLP's (restriction fragment length polymorphisms) and RAPD. Especially RAPD proved to be a valuable technique to construct a linkage map. Screening 80 primers (10-mer) resolved more than 120 markers. RAPD will eventually lead to flanking DNA sequences, which will be used to isolate and characterize the virulence gene. Sequence information of the virulence gene inG. rostochiensis for the H1 resistance gene can be used to devise primers for a PCR assay and may also provide a starting point to isolate other virulence genes.
Similar content being viewed by others
References
Bakker, J., 1987. Protein variation in cyst nematodes. PhD Thesis. Agricultural University Wageningen, the Netherlands. 159 pp.
Bakker, J. & Bouwman-Smits, L., 1988. Contrasting rates of protein and morphological evolution in cyst nematode species. Phytopathology 78: 900–904.
De Jong, A.J., Bakker, J., Roos, M. & Gommers, F.J., 1989. Repetitive DNA and hybridization patterns demonstrate extensive genetic differentiation of the sibling speciesGlobodera rostochiensis andG. pallida. Parasitology 99: 133–138.
Evans, K., Franco, J. & De Scurrah, M.M., 1975. Distribution of species of potato cyst-nematodes in South America. Nematologica 21: 365–369.
Fox, P.C. & Atkinson, H.J., 1986. Recent developments in the biochemical taxonomy of plant parasitic nematodes. In: Russell, G.E. (Ed.), Agricultural zoology reviews, Vol. 1. Intercept, Ponteland, Newcastle upon Tyne. 420 pp.
Goldman, D., Giri, P.R. & O'Brien, S.J., 1987. A molecular phylogeny of the homonoid primates as indicated by two-dimensional protein electrophoresis. Proceedings National Academy of Sciences USA 84: 3307–3311.
Janssen, R., 1990. Genetics of virulence in potato cyst nematodes. PhD Thesis. Agricultural University Wageningen, the Netherlands. 71 pp.
Janssen, R., Bakker, J. & Gommers, F.J., 1991. Mendelian proof for a gene-for-gene relationship between virulence ofGlobodera rostochiensis and the H1 resistance gene inSolanum tuberosum ssp.andigena CPC 1673. Revue de Nematologie 14: 213–219.
Jones, F.G.W., Parrott, D.M. & Perry, J.N., 1981. The gene-for-gene relationship and its significance for potato cyst nematodes and their solanaceous hosts. In: Zuckerman, B.M. & Rohde, R.A. (Eds), Plant parasitic nematodes. Academic Press, New York. 495 pp.
Kimura, M., 1983. The neutral theory of molecular evolution. Cambridge University Press, Cambridge, 367 pp.
Kort, J., Ross, H., Rumpenhorst, H.J. & Stone, A.R., 1978. An international scheme for identifying and classifying pathotypes of potato cyst-nematodesGlobodera rostochiensis andG. pallida. Nematologica 23: 333–339.
Platzer, E.G., 1981. Potential use of protein patterns and DNA nucleotide sequences in nematode taxonomy. In: Zuckerman, B.M. & Rohde, R.A. (Eds), Plant parasitic nematodes. Academic Press, New York. 495 pp.
Schots, A., 1988. A serological approach to the identification of potato cyst nematodes. PhD Thesis. Agricultural University Wageningen, the Netherlands. 118 pp.
Schots, A., Bakker, J., Gommers, F.J., Bouwman-Smits, L. & Egberts, E., 1987. Serological differentiation of the potato-cyst nematodesGlobodera pallida andG. rostochiensis: Partial purification of species specific proteins. Parasitology 95: 421–428.
Turner, S.J., Stone, A.R. & Perry, J.N., 1983. Selection of potato cyst-nematodes on resistantSolanum vernei hybrids. Euphytica 32: 911–917.
Williams, J.G.K., Kubelik, A.R., Livak, K.J., Rafalski, J.A. & Tingey, S.V., 1990. DNA polymorphisms amplified by arbitrary primers are useful as genetic markers. Nucleic Acids Research 18: 6531–6535.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Gommers, F.J., Roosien, J., Schouten, A. et al. Identification and management of virulence genes in potato cyst nematodes. Netherlands Journal of Plant Pathology 98 (Suppl 2), 157–163 (1992). https://doi.org/10.1007/BF01974482
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01974482