Genomic-led potato breeding for increasing genetic gains: achievements and outlook

Potato is the third most important crop, after rice and wheat, in human diets worldwide. Genetic gains due to its crossbreeding for productivity per se appear to be stagnant in this tetraploid crop. Its genetic enhancement needs to overcome inherent barriers such as ploidy, outcrossing and heterozygosity. Pathogens and pests affect potato because they may infect the entire plant, including stems, leaves and tubers, thus leading to significant tuber yield loss. Hence, host plant resistance breeding remains key for improving the productivity of this crop. This article reviews recent research advances relevant to potato breeding emphasizing genomic resources, methods and tools for genetic analysis, mapping of genes and quantitative trait loci, and genomic prediction of breeding values (or genomic selection) for population improvement. In this regard, association genetics has provided insights onto genetic architecture and inheritance of priority breeding traits, as well as tagging them to DNA markers for their further use as aids for indirect selection. Early research results show the feasibility of genomic selection as a new breeding approach for a tetrasomic polyploid such as potato. This manuscript also highlights the proposed inbred line strategy for producing diploid F1 true potato seed hybrids, and how its use may speed up and increase genetic gains in potato breeding; as well as promoting alleles through gene editing. The paper ends proposing a new interploidy breeding approach considering ploidy manipulations and incorporating genomic selection and gene editing for both population improvement and cultivar development