Abstract Cultivated apple is one of the most widely grown fruit crops worldwide. With the introduction of modern apple cultivars, from foreign and national breeding programs, the use of local cultivars decreased during the 20th century. In order to minimize genetic erosion and avoid loss of special genotypes, a number of local clonal archives were established across Sweden, with the goal of retaining old and local cultivars. About 220 apple cultivars, appointed for preservation, obtained the status of mandate cultivars. Initially, they were identified based on pomological traits, but prior to the establishment of the Swedish Central Collection they were genotyped with simple sequence repeat (SSR) markers. SSR markers helped to evaluate the status of the preserved material, as well as to find the best possible true-to-type source for propagation, thus guiding the establishment of the Central Collection. Recently, 215 accessions from this collection were genotyped using the 20 K apple Infinium® single nucleotide polymorphism (SNP) array, in order to gain insight into its genetic structure. The initial SSR analysis confirmed the identity of multiple samples with the same cultivar name grown in different locations and identified several mislabeled samples. In the subsequent SNP analysis we identified 30 clonal relationships and a number of parent-offspring relationships, including 18 trios. We also identified five cultivar samples with inconsistent ploidy levels between the SNP and SSR data, in some cases indicating problematic samples preserved in either the Central Collection or some of the local clonal archives. These cultivars need further investigation to ensure their true-to-typeness. Furthermore, the Swedish Central Collection has continued to grow since the onset of this work and now contains additional cultivars, which should be included in future studies. The results indicate that a number of the preserved mandate cultivars holds high potential value for modern breeding programs.

中文翻译：

---

瑞典中央收集的传家宝苹果品种的遗传状况

摘要 栽培苹果是世界范围内种植最广泛的水果作物之一。随着现代苹果品种的引进，从国外和国家的育种计划中，本地品种的使用在 20 世纪减少了。为了最大限度地减少遗传侵蚀并避免特殊基因型的丢失，瑞典各地建立了许多地方克隆档案，目的是保留古老的地方品种。约220个苹果品种获得委托品种资格。最初，它们是根据果树特征进行鉴定的，但在瑞典中央收藏馆建立之前，它们是用简单序列重复 (SSR) 标记进行基因分型的。SSR 标记有助于评估保存材料的状态，以及找到最佳的真实类型传播源，从而指导中央收藏的建立。最近，使用 20 K 苹果 Infinium® 单核苷酸多态性 (SNP) 阵列对该集合中的 215 份材料进行了基因分型，以深入了解其遗传结构。最初的 SSR 分析确认了在不同地点生长的具有相同品种名称的多个样品的身份，并确定了几个错误标记的样品。在随后的 SNP 分析中，我们确定了 30 个克隆关系和许多亲子关系，包括 18 个三重奏。我们还确定了 SNP 和 SSR 数据之间倍性水平不一致的五个栽培品种样本，在某些情况下，表明中央收藏或一些本地克隆档案中保存的有问题的样本。这些品种需要进一步调查以确保其真实性。此外，自这项工作开始以来，瑞典中央收藏一直在不断发展，现在包含其他栽培品种，这些品种应包括在未来的研究中。结果表明，许多保存的授权栽培品种对现代育种计划具有很高的潜在价值。