National Agriculture and Food Research Organization (NARO), Institute of Vegetable and Floriculture Science (NIVFS), 3-1-1 Kannondai, Tsukuba, Ibaraki, 305-8519, Japan.
NARO, NIVFS, 360 Kusawa, Ano, Tsu, Mie, 514-2392, Japan.
Theor Appl Genet. 2017 Aug;130(8):1601-1616. doi: 10.1007/s00122-017-2913-5. Epub 2017 May 5.
Using newly developed euchromatin-derived genomic SSR markers and a flexible Bayesian mapping method, 13 significant agricultural QTLs were identified in a segregating population derived from a four-way cross of tomato. So far, many QTL mapping studies in tomato have been performed for progeny obtained from crosses between two genetically distant parents, e.g., domesticated tomatoes and wild relatives. However, QTL information of quantitative traits related to yield (e.g., flower or fruit number, and total or average weight of fruits) in such intercross populations would be of limited use for breeding commercial tomato cultivars because individuals in the populations have specific genetic backgrounds underlying extremely different phenotypes between the parents such as large fruit in domesticated tomatoes and small fruit in wild relatives, which may not be reflective of the genetic variation in tomato breeding populations. In this study, we constructed F population derived from a cross between two commercial F cultivars in tomato to extract QTL information practical for tomato breeding. This cross corresponded to a four-way cross, because the four parental lines of the two F cultivars were considered to be the founders. We developed 2510 new expressed sequence tag (EST)-based (euchromatin-derived) genomic SSR markers and selected 262 markers from these new SSR markers and publicly available SSR markers to construct a linkage map. QTL analysis for ten agricultural traits of tomato was performed based on the phenotypes and marker genotypes of F plants using a flexible Bayesian method. As results, 13 QTL regions were detected for six traits by the Bayesian method developed in this study.
利用新开发的常染色质衍生基因组 SSR 标记和灵活的贝叶斯映射方法，在番茄四向杂交衍生的分离群体中鉴定出 13 个显著的农业 QTL。到目前为止，番茄的许多 QTL 作图研究都是针对来自两个遗传距离较远亲本的杂交后代进行的，例如，栽培番茄和野生近缘种。然而，在这种杂交群体中与产量相关的数量性状的 QTL 信息（例如花或果实数量，以及果实的总重量或平均重量）对于商业番茄品种的选育来说可能用处有限，因为群体中的个体具有非常不同的亲本表型下的特定遗传背景，例如栽培番茄中的大果实和野生近缘种中的小果实，这可能无法反映番茄育种群的遗传变异。在这项研究中，我们构建了番茄中来自两个商业 F 品种杂交的 F 群体，以提取对番茄育种实用的 QTL 信息。这种杂交对应于四向杂交，因为这两个 F 品种的四个亲本系被认为是创始人。我们开发了 2510 个新的基于表达序列标签（常染色质衍生）基因组 SSR 标记，并从这些新的 SSR 标记和公开可用的 SSR 标记中选择了 262 个标记来构建连锁图谱。利用灵活的贝叶斯方法，根据 F 植株的表型和标记基因型，对番茄的 10 个农业性状进行 QTL 分析。结果，该研究中开发的贝叶斯方法检测到 6 个性状的 13 个 QTL 区域。
