Use of FDR 2n Pollen to Transfer Resistance to Root-knot Nematodes into Cultivated 4 × Potatoes

Abstract Resistance to root-knot nematodes (RKN; Meloidogyne spp.) found in wild potato species (Solanum sparsipilum and S. chacoense) was transferred into an advanced 2x breeding population. Resistant genotypes were crossed with cultivated 2x clones and simultaneous selection applied for resistance, horticultural traits, and production of first-division restitution 2n pollen. Experiments were conducted to determine if resistant 2x clones with 2n pollen production would efficiently transmit their resistance to 4x progenies by means of 4x × 2x crosses. More than 2000 seedlings from 40 families derived from 2x × 2x, 4x × 2x, and 4x × 4x crosses were evaluated for resistance. It was found that: 1) 18% of the progeny derived from 4x (susceptible) × 2x (resistant) crosses were resistant to RKN. Thus, the 2n pollen producing 2x clones are valuable genetic material for the production of RKN-resistant 4x progenies; 2) The existence of resistant 4x progenies with either S. tuberosum spp. tuberosum or S. demissum cytoplasm indicated that S. sparsipilum cytoplasm was not essential for the expression of the resistance genes.