Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Development of nematode resistant crop plants

The project concerns the isolation of a gene from one of the wild beet species Bacillus procumbens or Bacillus patellans conferring resistance against the beet cyst nematode Heterodera schachtii and the introduction of this gene into sugar beet and rape seed in order to obtain nematode resistant varieties.

The strategy followed to clone the resistance gene was 'map-based cloning'.

During the period covered by this report research was focused on chromosome walking and on the identification of candidate resistance genes. The chromosome walking resulted in the isolation of 4 novel YAC clones. By using the cloned ends of the various YAC clones, the two different maps that were constructed previously could be integrated into a single comprehensive map of the Hs1(pro-1) locus. The experiments aiming at the isolation of candidate resistance genes yielded a large number of genes, isolated from resistant sugar beet lines, that show a high homology to plant resistance genes conferring resistance against pathogenic fungi, bacteria and viruses. However, it remains to be proven that the nematode resistance gene is amongst these isolated genes. A very promising candidate nematode resistance gene was isolated from one of the isolated YAC clones. This gene, referred to as 1832, was shown to confer full nematode resistance when expressed under the control of the CAMV 35S promoter in hairy roots of susceptible sugar beet. Since nematode resistant sugar beet plants are available which lack the 1832 gene, it must be concluded that probably more than one gene conferring nematode resistance can be found in the Hs1(pro-1) locus as present in the B. procumbens translocation lines.

Reported by

Centre for Plant Breeding and Reproduction Research CPRO - DLO
6700 AA Wageningen