Gosman N, Steed A, Hollins T W, Bayles R, Jennings P, Nicholson P
John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK.
Theor Appl Genet. 2009 Feb;118(4):695-702. doi: 10.1007/s00122-008-0930-0. Epub 2008 Nov 26.
Fusarium head blight (FHB) is an important disease of wheat worldwide. Soissons is one of the most resistant varieties grown in UK. The current study was undertaken to identify QTL for FHB resistance in Soissons and to determine whether the semi-dwarfing alleles Rht-B1b and Rht-D1b have a similar influence on susceptibility to FHB. A Soissons (Rht-B1b; Rht-D1a) x Orvantis (Rht-B1a; Rht-D1b) doubled haploid (DH) population was assessed for FHB resistance in three trials. Soissons contributed a single, stable major FHB QTL linked to the Rht-D1 locus. In contrast, the Rht-B1b allele (contributed by Soissons) conferred no negative effect on FHB resistance, even conferring a very minor positive effect in one trial. The influence of the Rht-B1b and Rht-D1b alleles on FHB resistance was further investigated using both Mercia and Maris Huntsman near-isogenic lines. Under high disease pressure both Rht-B1b and Rht-D1b significantly decreased Type 1 resistance (resistance to initial infection). However, whilst Rht-D1b has no effect on Type 2 resistance (resistance to spread of the fungus within the spike), Rht-B1b significantly increased Type 2 resistance. Our study demonstrates that the choice of semi-dwarfing gene used in plant breeding programmes may be a significant consideration where resistance to FHB is an important breeding target.
小麦赤霉病是一种在全球范围内对小麦来说都很重要的病害。苏瓦松是英国种植的最具抗性的品种之一。当前的研究旨在鉴定苏瓦松中抗小麦赤霉病的数量性状基因座（QTL），并确定半矮秆等位基因Rht - B1b和Rht - D1b对小麦赤霉病易感性是否有类似影响。在三项试验中对一个苏瓦松（Rht - B1b；Rht - D1a）×奥万蒂斯（Rht - B1a；Rht - D1b）双单倍体（DH）群体进行了小麦赤霉病抗性评估。苏瓦松贡献了一个与Rht - D1基因座连锁的单一、稳定的主要小麦赤霉病QTL。相比之下，Rht - B1b等位基因（由苏瓦松贡献）对小麦赤霉病抗性没有负面影响，甚至在一项试验中还表现出非常轻微的正向作用。利用梅西娅和马里斯·亨斯曼近等基因系进一步研究了Rht - B1b和Rht - D1b等位基因对小麦赤霉病抗性的影响。在高病害压力下，Rht - B1b和Rht - D1b均显著降低了1型抗性（对初始感染的抗性）。然而，虽然Rht - D1b对2型抗性（对真菌在穗内传播的抗性）没有影响，但Rht - B1b显著提高了2型抗性。我们的研究表明，在抗小麦赤霉病是重要育种目标的情况下，植物育种计划中使用的半矮秆基因的选择可能是一个重要的考虑因素。
