|Using comparative genomics to develop a new model of understanding Verticillium wilt resistance in potato.|
A. MEIER (1), D. Halterman (2). (1) University of Wisconsin, Madison, Madison, WI, U.S.A.; (2) USDA/ARS, Madison, WI, U.S.A.
Verticillium wilt (VW) is a persistent and costly disease affecting potato production. VW is caused by the soilborne fungi <i>Verticillium dahliae</i> and <i>V. albo-atrum. </i>Because of the difficulty in dealing with this disease, host resistance offers a low input, effective method of control. Most potato cultivars grown in the US are very susceptible, but sources of resistance have been identified in several wild relatives. In tomato, resistance to VW is conferred by Ve1, a member of a gene family encoding two membrane-bound, extracellular receptors. Homologs of Ve have been identified in wild and cultivated potato, including DM1-3, from the <i>S. tuberosum</i> group Phureja and reference for the potato genome sequence. Comparison of the Ve locus on chromosome 9 of VW susceptible DM1-3 and the resistant diploid hybrid C287 identified structural variation that could determine <i>Ve</i> gene function. Using comparative genomics and gene-expression analyses, we have developed a model for VW resistance and susceptibility in potato.