Field Performance and Resistance to Tuber Soft Rot of Potato Clones Derived from Sexual Polyploidization

Unilateral sexual polyploidization through 4x x 2x crosses is widely used to introgress genes from the diploid gene pool to the tetraploid cultivated potato Solanum tuberosum. Clones of eight 4x x 2x families, from crosses between four tetraploid cultivated potatoes and two diploid S. phureja – S. tuberosum hybrids, producing 2n pollen, were evaluated for yield performances and resistance to tuber soft rot. Significant differences in terms of tuber yield and number were found between families and clones, with several clones outyielding their tetraploid parents. The source of variation due to females (4x females GCA) was significant for both tuber yield and number. A number of clones displayed inheritance of resistance to tuber soft rot. No relationship was found between agronomic traits and resistance to soft rot. Results suggest that the genotypes produced represent genetic material with good potentiality in the constitution of new genotypes with interesting trait combinations.