Graduate School of Science and Technology, Niigata University, Ikarashi, Niigata, 950-2181, Japan.
Theor Appl Genet. 2010 May;120(7):1335-46. doi: 10.1007/s00122-010-1259-z. Epub 2010 Jan 13.
To perform comparative studies of CR (clubroot resistance) loci in Brassica oleracea and Brassica rapa and to develop marker-assisted selection in B. oleracea, we constructed a B. oleracea map, including specific markers linked to CR genes of B. rapa. We also analyzed CR-QTLs using the mean phenotypes of F(3) progenies from the cross of a resistant double-haploid line (Anju) with a susceptible double-haploid line (GC). In the nine linkage groups obtained (O1-O9), the major QTL, pb-Bo(Anju)1, was derived from Anju with a maximum LOD score (13.7) in O2. The QTL (LOD 5.1) located in O5, pb-Bo(GC)1, was derived from the susceptible GC. Other QTLs with smaller effects were found in O2, O3, and O7. Based on common markers, it was possible to compare our finding CR-QTLs with the B. oleracea CR loci reported by previous authors; pb-Bo(GC)1 may be identical to the CR-QTL reported previously or a different member contained in the same CR gene cluster. In total, the markers linked to seven B. rapa CR genes were mapped on the B. oleracea map. Based on the mapping position and markers of the CR genes, informative comparative studies of CR loci between B. oleracea and B. rapa were performed. Our map discloses specific primer sequences linked to CR genes and includes public SSR markers that will promote pyramiding CR genes in intra- and inter-specific crosses in Brassica crops. Five genes involved in glucosinolates biosynthesis were also mapped, and GSL-BoELONG and GSL-BoPro were found to be linked to the pb-Bo(Anju)1 and Bo(GC)1 loci, respectively. The linkage drag associated with the CR-QTLs is briefly discussed.
为了在甘蓝型油菜和白菜型油菜中进行 CR（根肿病抗性）基因座的比较研究，并在甘蓝型油菜中开发基于标记的选择，我们构建了一个甘蓝型油菜图谱，其中包括与白菜型油菜 CR 基因连锁的特异标记。我们还分析了来自抗性双单倍体系（Anju）与感病双单倍体系（GC）杂交的 F3 后代的平均表型的 CR-QTL。在获得的 9 个连锁群（O1-O9）中，主效 QTL pb-Bo(Anju)1 来自 Anju，在 O2 中最大的 LOD 得分（13.7）。位于 O5 的 QTL pb-Bo(GC)1 来自感病的 GC。在 O2、O3 和 O7 中发现了其他较小效应的 QTL。基于共同的标记，我们有可能将我们的 CR-QTL 与先前作者报道的甘蓝型油菜 CR 基因座进行比较；pb-Bo(GC)1 可能与先前报道的 CR-QTL 相同，或者是同一 CR 基因簇中包含的不同成员。共有 7 个白菜型油菜 CR 基因的标记被定位在甘蓝型油菜图谱上。基于 CR 基因的图谱定位和标记，对甘蓝型油菜和白菜型油菜的 CR 基因座进行了信息丰富的比较研究。我们的图谱揭示了与 CR 基因连锁的特异引物序列，并包括公共 SSR 标记，这将促进在芸薹属作物的种内和种间杂交中聚合 CR 基因。还对参与硫代葡萄糖苷生物合成的 5 个基因进行了作图，发现 GSL-BoELONG 和 GSL-BoPro 分别与 pb-Bo(Anju)1 和 Bo(GC)1 基因座连锁。简要讨论了与 CR-QTL 相关的连锁累赘。
