Diploid Potato Hybrids as Sources of Resistance to Blackspot Bruising

Resistance to bruising is an important quality trait of potato depending on multiple genetic and environmental factors. Thirty one interspecific diploid hybrids and two tetraploid standards were evaluated for resistance to bruising in 2 years. Diploids originated from crosses between wild and primitive Solanum species and dihaploids of S. tuberosum. Two-year mean values of bruising resistance of tested genotypes indicated significant variability of the trait. Analysis of variance showed significant effects of genotype, year and interaction between them on the trait. Broad-sense heritability of bruising resistance was estimated as moderately high, Hb = 0.73. Content of L-tyrosine, the main substrate of discoloration reaction, was not significantly correlated with brusing in tested diploid hybrids. The clones, that were resistant to blackspot bruise, also combined quality traits and resistances to many pathogens. All these traits could be transferred together into tetraploid level in 4x × 2x crosses via male 2n gametes produced by diploid hybrids.