Department of Agrobiotechnology, Institute of Biotechnology in Plant Production, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz Str. 20, 3430, Tulln, Austria.
Theor Appl Genet. 2022 Jun;135(6):1985-1996. doi: 10.1007/s00122-022-04088-x. Epub 2022 Apr 9.
The effect of the Rht1-genes on FHB resistance depends on anther extrusion and level of background resistance. Qfhs.ifa-5A increases resistance and anther extrusion as efficiently as semi-dwarfing alleles decrease it. The semi-dwarfing reduced height alleles Rht-D1b and Rht-B1b have been deployed in modern wheat cultivars throughout the world, but they increase susceptibility to Fusarium head blight (FHB). Here, we investigated the impact of the Rht1 genes on anther retention (AR) in relation to FHB resistance using four different sets of near-isogenic lines (NILs) with contrasting levels and types of background FHB resistance. NILs were evaluated for FHB severity, plant height and AR in three greenhouse and three field trials using artificial spray inoculation. Rht-B1b and Rht-D1b alleles increased AR and FHB susceptibility in all genetic backgrounds. The magnitude of the effects differed between NIL groups. Increased FHB susceptibility largely followed increased AR. Differences in FHB susceptibility between tall and dwarf haplotypes were largest in the NIL group with the highest changes in AR. In the most resistant NIL group, dwarfed lines had only slightly higher AR than tall lines and maintained good resistance, while both tall and dwarf lines had high levels of retained anthers in the most susceptible NIL group. We further investigated the effect of the major Fusarium resistance QTL Fhb1 and Qfhs.ifa-5A in combination with the Rht1 genes. Qfhs.ifa-5A enhanced anther extrusion in tall as well as semi-dwarf haplotypes, whereas Fhb1 did not affect AR. Qfhs.ifa-5A supported FHB resistance more efficiently than Fhb1 in lines that were more responsive to AR, while both Fhb1 and Qfhs.ifa-5A were equally efficient in NILs that had high background resistance and low response to AR.
Rht1 基因对赤霉病抗性的影响取决于花粉囊开裂和背景抗性水平。Qfhs.ifa-5A 像半矮化等位基因降低赤霉病抗性一样有效地提高抗性和花粉囊开裂。半矮化降低株高的等位基因 Rht-D1b 和 Rht-B1b 已在全世界的现代小麦品种中得到应用，但它们增加了对赤霉病（FHB）的易感性。在这里，我们使用具有不同水平和类型背景 FHB 抗性的四组近等基因系（NIL），研究了 Rht1 基因对花药保留（AR）与 FHB 抗性的关系。NIL 在三个温室和三个田间试验中通过人工喷雾接种评估了 FHB 严重度、株高和 AR。Rht-B1b 和 Rht-D1b 等位基因增加了所有遗传背景中的 AR 和 FHB 易感性。NIL 组之间效应的大小不同。增加的 FHB 易感性在很大程度上与增加的 AR 相关。高个子和矮个子单倍型之间的 FHB 易感性差异在 AR 变化最大的 NIL 组中最大。在最具抗性的 NIL 组中，矮化系的 AR 仅略高于高个子系，保持了良好的抗性，而在最易感性的 NIL 组中，高个子和矮个子系的花药都有较高的保留率。我们进一步研究了主要的 Fusarium 抗性 QTL Fhb1 和 Qfhs.ifa-5A 与 Rht1 基因的组合效应。Qfhs.ifa-5A 增强了高个子和半矮化单倍型的花粉囊开裂，而 Fhb1 不影响 AR。Qfhs.ifa-5A 在对 AR 反应更敏感的系中比 Fhb1 更有效地支持 FHB 抗性，而 Fhb1 和 Qfhs.ifa-5A 在具有高背景抗性和对 AR 反应低的 NIL 中效率相同。
