DNA marker-assisted evaluation of fruit acidity in diverse peach (Prunus persica) germplasm

Abstract

Fruit acidity is a major determinant of consumer-perceived fruit quality in peach. The non-acid peaches are preferred in the market and this trait is usually selected in commercial breeding programs. A major gene (D/d) located on chromosome 5 of peach has been described for this character, where the non-acid character is determined by the dominant D allele. The corresponding physical location estimated through linkage analysis is 0.9 Mb of the chromosome 5. In our study, we identified a SNP from re-sequencing 129 varieties through genome-wide association studies, and then genotyped a collection of 436 varieties on the Sequenom MassArray platform to verify the single nucleotide polymorphism (SNP) marker for this character. Two hundred and twelve accessions from 224 accessions tasting acid are TT. Two hundred accessions from 212 accessions tasting non-acid are TC or CC. The accuracy rate was 94.5 %. Based on the SNP marker, we also designed primers used for PCR to identify non-acid peaches. This approach was validated on 169 cultivars and 84 offspring. Data were always consistent and 160 cultivars (94.7 %) and 80 offspring (95.2 %) fit the expectations. These three methods of selecting non-acid plants are convenient and readily useful for peach molecular assisted selection.