Partially dominant resistance to Turnip yellows virus associated with one major QTL was identified in the natural allotetraploid oilseed rape cultivar Yudal. Turnip yellows virus (TuYV) is transmitted by the peach-potato aphid (Myzus persicae) and causes severe yield losses in commercial oilseed rape crops (Brassica napus). There is currently only one genetic resource for resistance to TuYV available in brassica, which was identified in the re-synthesised B. napus line 'R54'. In our study, 27 mostly homozygous B. napus accessions, either doubled-haploid (DH) or inbred lines, representing a diverse subset of the B. napus genepool, were screened for TuYV resistance/susceptibility. Partial resistance to TuYV was identified in the Korean spring oilseed rape, B. napus variety Yudal, whilst the dwarf French winter oilseed rape line Darmor-bzh was susceptible. QTL mapping using the established Darmor-bzh × Yudal DH mapping population (DYDH) revealed one major QTL explaining 36% and 18% of the phenotypic variation in two independent experiments. A DYDH line was crossed to Yudal, and reciprocal backcross (BC1) populations from the F1 with either the susceptible or resistant parent revealed the dominant inheritance of the TuYV resistance. The QTL on ChrA04 was verified in the segregating BC1 population. A second minor QTL on ChrC05 was identified in one of the two DYDH experiments, and it was not observed in the BC1 population. The TuYV resistance QTL in 'R54' is within the QTL interval on Chr A04 of Yudal; however, the markers co-segregating with the 'R54' resistance are not conserved in Yudal, suggesting an independent origin of the TuYV resistances. This is the first report of the QTL mapping of TuYV resistance in natural B. napus.

中文翻译：

---

油菜油菜抗萝卜黄病毒（TuYV）的鉴定和QTL定位。

在天然异源四倍体油菜品种 Yudal 中鉴定出与一种主要 QTL 相关的萝卜黄病毒的部分显性抗性。芜菁黄病毒 (TuYV) 由桃马铃薯蚜虫 (Myzus persicae) 传播，并导致商业油菜作物 (Brassica napus) 严重减产。目前在芸苔属植物中只有一种抗 TuYV 的遗传资源，在重新合成的欧洲油菜品系“R54”中发现了这种遗传资源。在我们的研究中，对代表欧洲油菜基因库不同子集的 27 个主要纯合的欧洲油菜种质（双单倍体 (DH) 或近交系）进行了 TuYV 抗性/易感性筛选。在韩国春油菜油菜品种 Yudal 中发现了对 TuYV 的部分抗性，而矮小的法国冬季油菜品系 Darmor-bzh 则易感。使用已建立的 Darmor-bzh × Yudal DH 作图群体 (DYDH) 作图的 QTL 显示了一个主要的 QTL，解释了两个独立实验中 36% 和 18% 的表型变异。将 DYDH 系与 Yudal 杂交，来自 F1 的互易回交 (BC1) 种群与易感或抗性亲本显示 TuYV 抗性的显性遗传。ChrA04 上的 QTL 在分离的 BC1 群体中得到验证。在两个 DYDH 实验之一中鉴定了 ChrC05 上的第二个次要 QTL，并且在 BC1 群体中没有观察到。'R54'中的TuYV抗性QTL在Yudal Chr A04的QTL区间内；然而，与“R54”抗性共分离的标记在 Yudal 中并不保守，表明TuYV抗性的独立起源。这是天然欧洲油菜中TuYV抗性QTL定位的第一份报告。