Gosman N, Steed A, Simmonds J, Leverington-Waite M, Wang Y, Snape J, Nicholson P
Crop Genetics, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK.
Theor Appl Genet. 2008 May;116(8):1145-53. doi: 10.1007/s00122-008-0742-2.
Fusarium head blight (FHB) is an important disease of wheat worldwide. The cultivar Spark is more resistant than most other UK winter wheat varieties but the genetic basis for this is not known. A mapping population from a cross between Spark and the FHB susceptible variety Rialto was used to identify quantitative trait loci (QTL) associated with resistance. QTL analysis across environments revealed nine QTL for FHB resistance and four QTL for plant height (PH). One FHB QTL was coincident with the Rht-1D locus and accounted for up to 51% of the phenotypic variance. The enhanced FHB susceptibility associated with Rht-D1b is not an effect of PH per se as other QTL for height segregating in this population have no influence on susceptibility. Experiments with near-isogenic lines supported the association between susceptibility and the Rht-D1b allele conferring the semi-dwarf habit. Our results demonstrate that lines carrying the Rht-1Db semi-dwarfing allele are compromised in resistance to initial infection (type I resistance) while being unaffected in resistance to spread within the spike (type II resistance).
小麦赤霉病（FHB）是一种在全球范围内对小麦来说都很重要的病害。品种Spark比大多数其他英国冬小麦品种更具抗性，但其抗性的遗传基础尚不清楚。利用Spark与感FHB品种Rialto杂交产生的一个作图群体来鉴定与抗性相关的数量性状位点（QTL）。跨环境的QTL分析揭示了9个FHB抗性QTL和4个株高（PH）QTL。一个FHB QTL与Rht-1D位点重合，占表型变异的比例高达51%。与Rht-D1b相关的FHB易感性增强并非株高本身的影响，因为该群体中分离的其他株高QTL对易感性没有影响。近等基因系实验支持了易感性与赋予半矮化习性的Rht-D1b等位基因之间的关联。我们的结果表明，携带Rht-1Db半矮化等位基因的品系在对初始感染的抗性（I型抗性）方面存在缺陷，而在对穗内病害传播的抗性（II型抗性）方面不受影响。
