Selection for verticillium wilt resistance in potato breeding populations derived from four cross types

Verticillium wilt (VW) is one of the important yield-limiting diseases for potato production. To develop resistant clones, the potential for early generation selection was studied using three basic selection methods, individual, family, and within family selection, for two clonal generations. A total of 152 clones were derived from four cross types (2x × 2x, 2x × 4x, 4x × 2x and 4x × 4x). Clones were evaluated for maturity, symptom expression, yield and stem colonization in replicated trials. Heritability and selection response for the traits were estimated for each selection method. Direct selection in the second clonal generation and individual selection showed more gain than that from other methods. Both 2x × 2x and 4x × 2x families were higher yielding and had lower stem colonization scores than 2x × 4x and 4x × 4x crosses. Therefore, 2x × 2x or 4x × 2x crosses between carefully chosen parents with high yield and VW resistance may produce offspring with superior performance.