Hales Benjamin, Steed Andrew, Giovannelli Vincenzo, Burt Christopher, Lemmens Marc, Molnár-Láng Marta, Nicholson Paul
Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK.
University of Natural Resources and Life Sciences, Institute for Biotechnology in Plant Production, Department of Agrobiotechnology, IFA Tulln, Tulln, Austria.
J Exp Bot. 2020 Aug 6;71(16):4703-4714. doi: 10.1093/jxb/eraa226.
Fusarium head blight (FHB) causes significant grain yield and quality reductions in wheat and barley. Most wheat varieties are incapable of preventing FHB spread through the rachis, but disease is typically limited to individually infected spikelets in barley. We point-inoculated wheat lines possessing barley chromosome introgressions to test whether FHB resistance could be observed in a wheat genetic background. The most striking differential was between 4H(4D) substitution and 4H addition lines. The 4H addition line was similarly susceptible to the wheat parent, but the 4H(4D) substitution line was highly resistant, which suggests that there is an FHB susceptibility factor on wheat chromosome 4D. Point inoculation of Chinese Spring 4D ditelosomic lines demonstrated that removing 4DS results in high FHB resistance. We genotyped four Chinese Spring 4DS terminal deletion lines to better characterize the deletions in each line. FHB phenotyping indicated that lines del4DS-2 and del4DS-4, containing smaller deletions, were susceptible and had retained the susceptibility factor. Lines del4DS-3 and del4DS-1 contain larger deletions and were both significantly more resistant, and hence had presumably lost the susceptibility factor. Combining the genotyping and phenotyping results allowed us to refine the susceptibility factor to a 31.7 Mbp interval on 4DS.
镰刀菌穗腐病（FHB）会导致小麦和大麦的谷物产量和品质显著下降。大多数小麦品种无法阻止FHB通过穗轴传播，但在大麦中，病害通常局限于单个受感染的小穗。我们对含有大麦染色体渗入片段的小麦品系进行了点接种，以测试在小麦遗传背景下是否能观察到FHB抗性。最显著的差异存在于4H(4D) 代换系和4H附加系之间。4H附加系对小麦亲本的敏感性相似，但4H(4D) 代换系具有高度抗性，这表明小麦4D染色体上存在一个FHB感病因子。对中国春4D双端体品系进行点接种表明，去除4DS会导致高FHB抗性。我们对四个中国春4DS末端缺失系进行了基因分型，以更好地表征每个品系中的缺失情况。FHB表型分析表明，含有较小缺失的del4DS - 2和del4DS - 4系易感病，并保留了感病因子。del4DS - 3和del4DS - 1系含有较大的缺失，均显著更抗病，因此可能已经失去了感病因子。结合基因分型和表型分析结果，我们将感病因子定位到了4DS上一个31.7 Mbp的区间内。
