Novel genomic regions associated with cold sweetening in native potatoes (Group Andigena) from Argentina

COLMAN, SILVANA LORENA; CARBONI, MARTÍN FEDERICO; CASTELLOTE, MARTÍN ALFREDO; MASSA, GABRIELA ALEJANDRA; FEINGOLD, SERGIO ENRIQUE

Fos de Iguazu

Congreso; 1th International Congress of Plant Molecular Biology IPMB2015; 2015

The accumulation of reducing sugars in potato tubers exposed to cold temperatures is referred to as cold induced sweetening (CIS). The molecular basis of CIS is of interest since high amounts of reducing sugars negatively affect potato chips quality. Genes involved in carbohydrate metabolism have been identified on the potato genome. Among others, invertase genes on chromosomes III, IX and X were identified as candidates for CIS.Genetic diversity of Solanum tuberosum Group Andigena constitutes a valuable resource that can contribute to overcome this important commercial constraint. Previously, a collection of Andean native potatoes showed high diversity cold sweetening responses, with genotypes presenting low reducing sugar content and good chip quality, even after cold storage. Association between alleles of invertase genes with CIS resistance, were identified.In this study, we exhaustively explored genetic polymorphisms of this Andigena collection using DArTseq TM . A total of 56,169 SNPs were generated and mapped. From these, 4795 highly reproducible SNPs were selected to carry out an association with tuber reducing sugar content and chip quality in freshly harvested and cold stored tubers. Structure software, UPGMA and PCA analysis were used to determinate the population structure. A mixed linear model analysis was used to unveil associations. We have found genomic regions in chromosomes: I, II, VI, VII, IX and X associated to reducing sugars content and chip quality (p<0.005) after cold storage. Some of these regions have not been previously reported linked to CIS resistance, and are a novel source for new candidate genes for this trait.