Known since ancient times, flat-shaped peach (Prunus persica L. Batsch) fruits have aroused considerable research interest. Breeding activities for this trait have expanded since the 1980s of the last century in several countries, in parallel with research into its genetic basis. Following the need for molecular markers to assist selection, linkage mapping studies have positioned the flat shape S locus at the end of chromosome 6. Recently, a series of independent studies focused on detailed characterization of the genomic region harbouring the S locus and different hypotheses about the candidate gene or variant were proposed: from a constitutively activated cell death 1 protein (PpCAD1) to a Brassinosteroid insensitive 1-associated receptor kinase 1 group (PpLRR-RLK) until the discovery of large structural variant (a chromosomal inversion of about 1.7 Mb) putatively affecting an OVATE Family Protein (PpOFP1) and a homolog of sucrose non-fermenting 1-related kinase (PpSNF4), respectively, located at the proximal and distal breakpoints. This short review revises historical studies and recent literature, integrating reanalysis of available genetic and genomic data, to provide a critical overview of the topic and highlight avenues for further research.

自古以来，扁形桃（Prunus persica L. Batsch ）果实就引起了人们相当大的研究兴趣。自上个世纪 80 年代以来，在一些国家开展了该性状的育种活动，同时对其遗传基础进行了研究。由于需要分子标记来辅助选择，连锁作图研究将扁平形状的S基因座定位在 6 号染色体的末端。 最近，一系列独立研究侧重于对包含S基因座的基因组区域的详细表征以及关于提出了候选基因或变体：来自组成性激活的细胞死亡 1 蛋白 ( PpCAD1) 到油菜素类固醇不敏感 1 相关受体激酶 1 组 ( PpLRR-RLK )，直到发现可能影响 OVATE 家族蛋白 ( PpOFP1 ) 和蔗糖非发酵同源物的大结构变异（约 1.7 Mb 的染色体倒位） 1 相关激酶 ( PpSNF4 ) 分别位于近端和远端断点处。这篇简短的评论修订了历史研究和最近的文献，整合了对可用遗传和基因组数据的重新分析，以提供对该主题的重要概述，并突出了进一步研究的途径。