Acidity and sweetness are important qualities for apple breeders and understanding their genetic regulation can improve the breeding process. In previous QTL studies, fruit quality assessments were performed using instrumental measurements, leading to the identification of two major QTL Ma and Ma3. Here, we use sensorial data to investigate the role of known and unknown genetic factors in the perception of acidity and sweetness in three pedigreed full-sib families. For 2 years, these families were phenotyped by a trained panel, at harvest and after 2 months of cold storage, and genotyped with a new 50 K SNP array. FlexQTL^TM analyses using both an additive and an additive + dominance model resulted in the identification of Ma and Ma3 for acidity as well as sweetness, whereas the use of the additive model yielded decisive evidence for the discovery of two additional QTL on LG1 and LG6 for acidity. QTL genotypes were qualified as the inverse of each other, which indicates that individuals with the less-acidity alleles of Ma and Ma3 are perceived sweeter. Due to the genetic configuration in the families studied, resulting from a link with the Pale Green Disorder locus, no incomplete dominance effect could be detected for the Ma locus, although previously reported in the literature. For the Ma3 locus, however, an incomplete dominance effect (58%) is reported here for the first time. The Ma3 locus was also further confined to a 2–4-cM region and a predictive marker for this locus was identified.

酸度和甜度是苹果育种者的重要素质，了解他们的遗传调控可以改善育种过程。在先前的QTL研究中，使用仪器测量进行了水果质量评估，从而鉴定出两个主要的QTL Ma和Ma3。在这里，我们使用感官数据来调查已知和未知遗传因素在三个纯正同胞家庭中对酸度和甜度的感知中的作用。在过去的2年中，这些家庭在收获时和冷藏2个月后由经过培训的专家小组进行表型鉴定，并使用新的50 K SNP阵列进行基因分型。使用加性和加性+优势模型的FlexQTL ^TM分析导致鉴定了Ma和Ma3用于酸度和甜度，而添加模型的使用为在LG1和LG6酸度上发现两个额外的QTL提供了决定性的证据。QTL基因型彼此相反，这表明Ma和Ma3的酸度较低的等位基因个体被认为更甜。由于研究的家族的遗传结构，是由于与淡绿色疾病基因座相关，因此没有检测到Ma基因座的不完全优势作用，尽管先前已有文献报道。然而，对于Ma3基因座，首次报道了不完全的显性作用（58％）。该MA3 进一步将基因座限制在2-4cM区域，并确定了该基因座的预测标记。