Columnar-shaped apple (Malus × domestica Borkh.) trees are of interest because of their profitable and labour-saving characteristics based on high-density planting and robotic technologies. Recent studies have shown that the Co gene, which is responsible for the columnar shape, and MdPG1, which contributes to fruit storability and flesh texture, are located on chromosome 10 of the apple genome. In silico analysis and genotypic characterisation of our columnar breeding materials revealed that the unfavourable haplotype carrying both Co and the MdPG1-3 allele that confers low storability was retained in almost all of our current and historical columnar materials because of the strong linkage between the two genes. To overcome this limitation, we conducted large-scale marker-assisted selection to obtain plants harbouring a favourable haplotype conferring a columnar tree with improved storability, and high-quality flesh resulting from recombination events between these genes during meiosis. Large-scale marker-assisted selection of approximately 15,000 seedlings composed of five crosses resulted in the identification of 80 individuals harbouring the targeted recombinant haplotype. These individuals are valuable for breeding columnar apple cultivars with superior fruit quality.

柱状苹果树（Malus × Domestica Borkh.）因其基于高密度种植和机器人技术的有利可图和节省劳动力的特点而备受关注。最近的研究表明，负责柱状形状的Co基因和负责果实耐贮性和果肉质地的MdPG1基因位于苹果基因组的 10 号染色体上。我们的柱状育种材料的计算机分析和基因型表征表明，由于两个基因之间的紧密联系，几乎所有我们当前和历史的柱状材料中都保留了携带Co和MdPG1 -3等位基因的不利单倍型，赋予低耐贮性。 。为了克服这一限制，我们进行了大规模的标记辅助选择，以获得具有有利单倍型的植物，赋予柱状树以改善的耐贮性，以及在减数分裂期间这些基因之间的重组事件产生的高质量果肉。对由五个杂交组成的约 15,000 株幼苗进行大规模标记辅助选择，结果鉴定出 80 个携带目标重组单倍型的个体。这些个体对于培育具有优良果实品质的柱状苹果品种具有重要价值。