Apple Fruit Size QTLs on Chromosomes 8 and 16 Characterized in ‘Honeycrisp’-Derived Germplasm

Multiple quantitative trait loci (QTLs) associated with fruit size have been reported in apple (Malus domestica Borkh.); however, few fully characterized and/or validated. A pedigree-based QTL analysis approach was used to examine the genetic basis of weight ‘Honeycrisp’-derived germplasm. Fourteen breeding parents were represented by 814 offspring from 13 full-sib families ‘Honeycrisp’ and ‘Minneiska’ being highly represented. Historical data curated genome-wide single nucleotide polymorphism (SNP) leveraged map QTLs chromosomes (Chrs) 8 16, which together accounted for 15% phenotypic variation. The Chr 16 colocalized other important loci. inherited two low haplotypes at progenitors ‘Northern Spy’ ‘Grimes Golden’. At QTL, a haplotype ‘Frostbite’ high ‘Duchess Oldenburg’. small-fruited progenitor had three across QTLs. Non-additive interactions observed Results will enable more informed parent selection development trait-predictive DNA tests use programs.