title: DNA variation at the invertase locus invGE/GF is associated with tuber quality traits in populations of potato breeding clones.
abstract: Starch and sugar content of potato tubers are quantitative traits, which are models for the candidate gene approach for identifying the molecular basis of quantitative trait loci (QTL) in noninbred plants. Starch and sugar content are also important for the quality of processed products such as potato chips and French fries. A high content of the reducing sugars glucose and fructose results in inferior chip quality. Tuber starch content affects nutritional quality. Functional and genetic models suggest that genes encoding invertases control, among other things, tuber sugar content. The invGE/GF locus on potato chromosome IX consists of duplicated invertase genes invGE and invGF and colocalizes with cold-sweetening QTL Sug9. DNA variation at invGE/GF was analyzed in 188 tetraploid potato cultivars, which have been assessed for chip quality and tuber starch content. Two closely correlated invertase alleles, invGE-f and invGF-d, were associated with better chip quality in three breeding populations. Allele invGF-b was associated with lower tuber starch content. The potato invertase gene invGE is orthologous to the tomato invertase gene Lin5, which is causal for the fruit-sugar-yield QTL Brix9-2-5, suggesting that natural variation of sugar yield in tomato fruits and sugar content of potato tubers is controlled by functional variants of orthologous invertase genes.
authors.affiliation: Max-Planck Institut für Züchtungsforschung, Köln, Germany.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Josef
authors.initials: J
authors.lastname: Strahwald
authors.forename: Hans-Reinhard
authors.initials: HR
authors.lastname: Hofferbert
authors.forename: Jens
authors.initials: J
authors.lastname: Lübeck
authors.forename: Eckart
authors.initials: E
authors.lastname: Tacke
authors.forename: Holger
authors.initials: H
authors.lastname: Junghans
authors.forename: Jörg
authors.initials: J
authors.lastname: Wunder
authors.forename: Christiane
authors.initials: C
authors.lastname: Gebhardt
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D005632:Fructose / Q000737:chemistry; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D005947:Glucose / Q000737:chemistry; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D040641:Quantitative Trait Loci; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000235:genetics*; D043324:beta-Fructofuranosidase / Q000235:genetics*
chemical_list: D017931:DNA Primers; D005632:Fructose; D004247:DNA; D043324:beta-Fructofuranosidase; D005947:Glucose