Lettuce is one of the economically important leaf vegetables and is cultivated mainly in temperate climate areas. Cultivar identification based on the distinctness, uniformity, and stability (DUS) test is a prerequisite for new cultivar registration. However, DUS testing based on morphological features is time-consuming, labor-intensive, and costly, and can also be influenced by environmental factors. Thus, molecular markers have also been used for the identification of genetic diversity as an effective, accurate, and stable method. Currently, genome-wide single nucleotide polymorphisms (SNPs) using next-generation sequencing technology are commonly applied in genetic research on diverse plant species. This study aimed to establish an effective and high-throughput cultivar identification system for lettuce using core sets of SNP markers developed by genotyping by sequencing (GBS). GBS identified 17 877 high-quality SNPs for 90 commercial lettuce cultivars. Genetic differentiation analyses based on the selected SNPs classified the lettuce cultivars into three main groups. Core sets of 192, 96, 48, and 24 markers were further selected and validated using the Fluidigm platform. Phylogenetic analyses based on all core sets of SNPs successfully discriminated individual cultivars that have been currently recognized. These core sets of SNP markers will support the construction of a DNA database of lettuce that can be useful for cultivar identification and purity testing, as well as DUS testing in the plant variety protection system. Additionally, this work will facilitate genetic research to improve breeding in lettuce.

中文翻译：

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全基因组 SNP 标记核心组和 Fluidigm 分析用于快速有效地鉴定韩国莴苣（Lactuca sativa L.）品种的基因型

莴苣是经济上重要的叶菜之一，主要种植在温带气候地区。基于独特性、一致性和稳定性（DUS）测试的品种鉴定是新品种注册的先决条件。然而，基于形态特征的 DUS 检测费时、费力、成本高，并且还可能受到环境因素的影响。因此，分子标记也作为一种有效、准确和稳定的方法被用于遗传多样性的鉴定。目前，使用下一代测序技术的全基因组单核苷酸多态性（SNP）通常应用于不同植物物种的遗传研究。本研究旨在利用通过测序基因分型 (GBS) 开发的核​​心 SNP 标记集建立有效且高通量的生菜品种鉴定系统。GBS 为 90 个商业生菜品种鉴定了 17 877 个高质量 SNP。基于所选 SNP 的遗传分化分析将莴苣品种分为三个主要组。使用 Fluidigm 平台进一步选择和验证了 192、96、48 和 24 个标记的核心集。基于所有核心 SNP 集的系统发育分析成功地区分了目前已被识别的单个品种。这些核心 SNP 标记集将支持构建生菜 DNA 数据库，该数据库可用于品种鉴定和纯度测试，以及植物品种保护系统中的 DUS 测试。此外，