Development of a molecular marker associated with Verticillium wilt resistance in diploid interspecific potato hybrids

Verticillium wilt (VW) is a widespread and serious potato (Solanum tuberosum) disease caused by the soilborne fungi Verticillium dahliae and V. albo-atrum. Breeding for VW resistance in potato is challenging due to ambiguous symptom expression, a lack of high throughput screening techniques, and variability in colonization by the fungus among and within plants. Genetic studies have identified major genes that confer resistance in diploid Solanum chacoense (Vc) and interspecific hybrids (Vw and Vt). However, to date, these genes have not been used to develop molecular markers for the identification of resistant clones. Tomato Ve1 and Ve2 gene sequence information was used to amplify candidate Ve gene orthologs from both resistant and susceptible diploid potato hybrids. A CAPS marker was generated to track VW resistance in a backcross population segregating for resistance. The marker was also tested for its usefulness in other breeding lines. Our results indicate that this marker is effective for selection of the Vw gene in segregating breeding populations.