Department of Life Science, The Catholic University of Korea, Bucheon, 420-743, Korea.
Mol Genet Genomics. 2014 Apr;289(2):149-60. doi: 10.1007/s00438-013-0798-9. Epub 2013 Dec 11.
Brassica rapa is a member of the Brassicaceae family and includes vegetables and oil crops that are cultivated worldwide. The introduction of durable resistance against turnip mosaic virus (TuMV) into agronomically important cultivars has been a significant challenge for genetic and horticultural breeding studies of B. rapa. Based on our previous genome-wide analysis of DNA polymorphisms between the TuMV-resistant doubled haploid (DH) line VC40 and the TuMV-susceptible DH line SR5, we constructed a core genetic map of the VCS-13M DH population, which is composed of 83 individuals derived from microspore cultures of a F1 cross between VC40 and SR5, by analyzing the segregation of 314 sequence-characterized genetic markers. The genetic markers correspond to 221 SNPs and 31 InDels of genes as well as 62 SSRs, covering 1,115.9 cM with an average distance of 3.6 cM between the adjacent marker loci. The alignment and orientation of the constructed map showed good agreement with the draft genome sequence of Chiifu, thus providing an efficient strategy to map genic sequences. Using the genetic map, a novel dominant TuMV resistance locus (TuMV-R) in the VCS-13M DH population was identified as a 0.34 Mb region in the short arm of chromosome A6 in which four CC-NBS-LRR resistance genes and two pathogenesis-related-1 genes reside. The genetic map developed in this study can play an important role in the genetic study of TuMV resistance and the molecular breeding of B. rapa.
白菜型油菜是十字花科芸薹属植物，包括全世界广泛种植的蔬菜和油料作物。将持久抗芜菁花叶病毒（TuMV）的特性导入具有重要农艺性状的品种一直是白菜型油菜遗传和园艺育种研究的一个重大挑战。基于我们先前对 TuMV 抗性双单倍体（DH）系 VC40 和 TuMV 敏感 DH 系 SR5 之间全基因组 DNA 多态性的分析，我们构建了一个由 83 个个体组成的 VCS-13M DH 群体核心遗传图谱，这些个体是由 VC40 和 SR5 的 F1 杂交后代的小孢子培养而来，通过分析 314 个序列特征遗传标记的分离情况。这些遗传标记对应于 221 个 SNP 和 31 个基因内插入/缺失（InDels）以及 62 个 SSRs，覆盖了 1115.9 cM，相邻标记位点之间的平均距离为 3.6 cM。构建图谱的比对和定向与 Chiifu 的草图基因组序列高度一致，因此为基因序列作图提供了一种有效的策略。利用遗传图谱，在 VCS-13M DH 群体中鉴定到一个新的显性 TuMV 抗性基因座（TuMV-R），位于第 6 号染色体短臂上，大小为 0.34 Mb，包含 4 个 CC-NBS-LRR 抗性基因和 2 个病程相关蛋白-1 基因。本研究中构建的遗传图谱可在白菜型油菜 TuMV 抗性的遗传研究和分子育种中发挥重要作用。
