title: Natural DNA variation at candidate loci is associated with potato chip color, tuber starch content, yield and starch yield.
abstract: Complex characters of plants such as starch and sugar content of seeds, fruits, tubers and roots are controlled by multiple genetic and environmental factors. Understanding their molecular basis will facilitate diagnosis and combination of superior alleles in crop improvement programs ("precision breeding"). Association genetics based on candidate genes is one approach toward this goal. Tetraploid potato varieties and breeding clones related by descent were evaluated for 2 years for chip quality before and after cold storage, tuber starch content, yield and starch yield. Chip quality is inversely correlated with tuber sugar content. A total of 36 loci on 11 potato chromosomes were evaluated for natural DNA variation in 243 individuals. These loci included microsatellites and genes coding for enzymes that function in carbohydrate metabolism or transport (candidate loci). The markers were used to analyze population structure and were tested for association with the tuber quality traits. Highly significant and robust associations of markers with 1-4 traits were identified. Most frequent were associations with chip quality and tuber starch content. Alleles increasing tuber starch content improved chip quality and vice versa. With two exceptions, the most significant and robust associations (q < 0.01) were observed with DNA variants in genes encoding enzymes that function in starch and sugar metabolism or transport. Comparing linkage and linkage disequilibrium between loci provided evidence for the existence of large haplotype blocks in the breeding materials analyzed.
authors: Department Plant Breeding and Genetics, MPI for Plant Breeding Research, Carl von Linné Weg 10, 50829 Cologne, Germany.
authors: Li
authors: L
authors: Li
authors: Maria-João
authors: MJ
authors: Paulo
authors: Josef
authors: J
authors: Strahwald
authors: Jens
authors: J
authors: Lübeck
authors: Hans-Reinhard
authors: HR
authors: Hofferbert
authors: Eckhart
authors: E
authors: Tacke
authors: Holger
authors: H
authors: Junghans
authors: Jörg
authors: J
authors: Wunder
authors: Astrid
authors: A
authors: Draffehn
authors: Fred
authors: F
authors: van Eeuwijk
authors: Christiane
authors: C
authors: Gebhardt
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D017343:Genes, Plant; D014644:Genetic Variation; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics*; D035281:Plant Tubers / Q000235:genetics* / Q000378:metabolism; D040641:Quantitative Trait Loci; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism; D013213:Starch / Q000235:genetics* / Q000378:metabolism
chemical_list: D018744:DNA, Plant; D013213:Starch