title: Novel SNP markers in InvGE and SssI genes are associated with natural variation of sugar contents and frying color in Solanum tuberosum Group Phureja.
abstract: Potato frying color is an agronomic trait influenced by the sugar content of tubers. The candidate gene approach was employed to elucidate the molecular basis of this trait in Solanum tuberosum Group Phureja, which is mainly diploid and represents an important genetic resource for potato breeding. The objective of this research was to identify novel genetic variants related with frying quality in loci with key functions in carbohydrate metabolism, with the purpose of discovering genetic variability useful in breeding programs. Therefore, an association analysis was implemented with 109 SNP markers identified in ten candidate genes.
  
  
  
  The analyses revealed four associations in the locus InvGE coding for an apoplastic invertase and one association in the locus SssI coding for a soluble starch synthase. The SNPs SssI-C45711901T and InvGE-C2475454T were associated with sucrose content and frying color, respectively, and were not found previously in tetraploid genotypes. The rare haplotype InvGE-A2475187C2475295A2475344was associated with higher fructose contents. Our study allowed a more detailed analysis of the sequence variation of exon 3 from InvGE, which was not possible in previous studies because of the high frequency of insertion-deletion polymorphisms in tetraploid potatoes.
  
  
  
  The association mapping strategy using a candidate gene approach in Group Phureja allowed the identification of novel SNP markers in InvGE and SssI associated with frying color and the tuber sugar content measured by High Performance Liquid Chromatography (HPLC). These novel associations might be useful in potato breeding programs for improving quality traits and to increase crop genetic variability. The results suggest that some genes involved in the natural variation of tuber sugar content and frying color are conserved in both Phureja and tetraploid germplasm. Nevertheless, the associated variants in both types of germplasm were present in different regions of these genes. This study contributes to the understanding of the genetic architecture of tuber sugar contents and frying color at harvest in Group Phureja.
authors.affiliation: Faculty of Agricultural Sciences, Agronomy Department, National University of Colombia, Bogotá, Colombia.|Present address: INRES-Plant Breeding, University of Bonn, Bonn, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Duarte-Delgado
authors.affiliation: Faculty of Agricultural Sciences, Agronomy Department, National University of Colombia, Bogotá, Colombia.
authors.forename: Deissy
authors.initials: D
authors.lastname: Juyó
authors.affiliation: Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Gebhardt
authors.affiliation: Faculty of Sciences, Biology Department, National University of Colombia, Bogotá, Colombia.
authors.forename: Felipe
authors.initials: F
authors.lastname: Sarmiento
authors.affiliation: Faculty of Agricultural Sciences, Agronomy Department, National University of Colombia, Bogotá, Colombia. tmosquerav@unal.edu.co.
authors.forename: Teresa
authors.initials: T
authors.lastname: Mosquera-Vásquez
mesh_terms: D050260:Carbohydrate Metabolism; D010940:Plant Proteins / Q000235:genetics*; D035281:Plant Tubers / Q000235:genetics / Q000378:metabolism; D011003:Ploidies; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D017422:Sequence Analysis, DNA / Q000379:methods; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins
keywords: Association mapping; Candidate genes; Carbohydrate metabolism; Potato frying quality