Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 2002
Publication Date: N/A
Verticillium wilt is a vascular disease predominantly caused by the soil borne fungi Verticillium dahliae and Verticillium albo atrum. Most of the commercial potato cultivars grown in the USA are susceptible to Verticillium, resulting in significant crop losses. Development of new cultivars with resistance gene(s) against the pathogen can be assisted with molecular marker technology that allows identification and tracking of resistance genes. In tomato, resistance to Verticillium dahliae is conferred by two closely linked genes (Ve1, Ve2) that were mapped to chromosome 9. We have employed primers that amplify the leucine rich repeat (LRR) domain from tomato Ve1 and Ve2 genes. Verticillium resistance gene homologues have been detected in resistant cv. Reddale when using these primers and genomic DNA as a template. Deduced amino acid sequence shared high identity with Ve1 (87% 90%) and Ve2 (88% 91%) tomato resistance genes. The StVe1 a potato homologue to the Ve1 gene mapped to the corresponding genomic position as tomato Ve1 gene. Microsatellite markers linked to the StVe1 have been used to screen 48 (mostly) tetraploid genotypes of various pedigrees. One of the tested markers showed high linkage with Verticillium resistance (p < 0.001). The correlation is mainly based on the complete absence of resistant genotypes that lack the STM1051 marker (~190bp size band). The STM1051 marker has a potential use in the easy and rapid detection of genotypes that are susceptible to Verticillium. Our results suggest that there may be a direct evolutionary relationship between Verticillium resistance genes in potato and tomato.