Fine Mapping of the Gene Controlling the Fruit Skin Hairiness of Prunus persica and Its Uses for MAS in Progenies

The fruit skin pubescence of Prunus persica is an economically important characteristic and comprises the classification criteria. The mapping and identification of a complete linkage marker to the fruit skin trichome trait locus of peach fruit are critical for the molecular marker-assisted selection for peach/nectarine. In this study, the BC(1) population was constructed from the parents “Zhongyou No. 4”, the recurrent parent, and “Baihuashanbitao”, the non-recurrent parent. Based on the 38 BC(1) individuals’ phenotypes and their genotyping using next-generation sequencing, the G (Glabrous skin) locus of the gene was first identified between 14.099 and 16.721 Mb on chromosome 5. Using other individuals of this population, the gene was fine-mapped in the range of 481 kb with SNP markers. Based on the resequencing data of other cultivars (lines), the candidate SNP in the gene Prupe.5G196400 was obtained. Subsequently, the SNP marker was designed and applied to natural and hybrid peach populations. Via genotyping analysis, we confirmed co-segregation between the peach/nectarine phenotype, which was used in the identification of peach or nectarine with 100% accuracy.