Potato (Solanum tuberosum L.) is one of the most important crops for human consumption worldwide, representing an essential component for the food security of several countries. However, yield and quality are negatively affected by biotic and abiotic stresses. In this sense, the selection of potato cultivars tolerant to heat and resistant to diseases is of great importance. Our goal was to select clones suitable for the chips industry, having heat tolerance and bearing the Rx1 and Ryadg alleles, which confer resistance to Potato virus X and Potato virus Y. We evaluated 491 clones originating from 31 biparental crosses under three different seasons in terms of heat stress (without heat stress [WHS], moderate heat stress [MHS], and high heat stress [HHS]). The evaluated traits were specific gravity (SG), dry matter yield (DMY), and proportion of physiological disorders (PD). After evaluation in the WHS and MHS seasons, the presence of the Rx1 and Ryadg alleles was investigated with the help of molecular markers in the 68 clones showing the best performance, which descended from the DGN2103 and DGN4002 parental clones. To gather the genotypic values for all traits in each season, the clones were ranked according to an index based on the genotype–ideotype distance. On average of all seasons, the top 10% selected clones by the index were 9 and 0.1% higher than the Atlantic cultivar for the traits DMY and SG, respectively, and 80% lower than Atlantic cultivar for PD. In conclusion, we report the selection of potato clones suitable for industrial processing.

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-Potato (Solanum tuberosum L.) breeding for PVY resistance is of utmost importance, in view of

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The Ry adg allele is widely used by breeders to confer extreme resistance to all strains of PVY. However, the necrotic strain has increased recombination resulting in recent considerable losses in productivity. Thus far, not all necrotic recombinant strains of PVY have been tested for their reaction to the Ry gene. The objective of this study was to identify potato clones carrying the resistant allele and to assess their reaction to the following recombinant strains: NTN (PVY NTN), Wilga (PVY N-Wi), and "curly top" (PVY E). Advanced clones from the potato breeding program at Universidade Federal de Lavras were evaluated through a specific molecular marker for the Ry adg allele. The clones carrying the resistance allele were grafted on tobacco plants infected with necrotic recombinant strains of PVY. The clones carrying the allele for resistance to PVY were not infected with any of the recombinants during the grafting test. These results confirm that resistance to necrotic recombinant strains has not yet been overcome and that the Ry adg allele also confers resistance to the three recombinant strains tested.