Liu S, Abate Z A, Lu H, Musket T, Davis G L, McKendry A L
Division of Plant Sciences, University of Missouri-Columbia, Columbia, MO 65211, USA.
Theor Appl Genet. 2007 Aug;115(3):417-27. doi: 10.1007/s00122-007-0577-2. Epub 2007 Jun 14.
Fusarium head blight (FHB), mainly caused by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schw. (Petch)], is an increasingly important disease of wheat (Triticum aestivum L.). Host-plant resistance provides the best hope for reducing economic losses associated with FHB, but new sources of resistance are limited. The moderately resistant winter wheat cultivar, Ernie, may provide a source of resistance that differs from Sumai 3 but these genes have not been mapped. Also hindering resistance breeding may be associations of resistance with agronomic traits such as late maturity that may be undesirable in some production environments. This research was conducted to identify QTL associated with type II FHB resistance (FHB severity, FHBS), and to determine if they are associated with days to anthesis (DTA), number of spikelets (NOS), and the presence/absence of awns. Two hundred and forty-three F(8) recombinant inbred lines from a cross between the resistant cultivar, Ernie and susceptible parent, MO 94-317 were phenotyped for type II FHB resistance using point inoculation in the greenhouse during 2002 and 2003. Genetic linkage maps were constructed using 94 simple sequence repeat (SSR) and 146 amplified fragment length polymorphic (AFLP) markers. Over years four QTL regions on chromosomes 2B, 3B, 4BL and 5A were consistently associated with FHB resistance. These QTL explained 43.3% of the phenotypic variation in FHBS. Major QTL conditioning DTA and NOS were identified on chromosome 2D. Neither the QTL associated with DTA and NOS nor the presence/absence of awns were associated with FHB resistance in Ernie. Our results suggest that the FHB resistance in Ernie appears to differ from that in Sumai 3, thus pyramiding the QTL in Ernie with those from Sumai 3 could result in enhanced levels of FHB resistance in wheat.
小麦赤霉病（FHB）主要由禾谷镰刀菌Schwabe [有性态：玉蜀黍赤霉Schw. (Petch)] 引起，是小麦（Triticum aestivum L.）上一种日益重要的病害。寄主植物抗性为减少与小麦赤霉病相关的经济损失提供了最大希望，但新的抗性来源有限。中度抗病的冬小麦品种Ernie可能提供了一种不同于苏麦3号的抗性来源，但这些基因尚未定位。抗性与诸如晚熟等农艺性状的关联也可能阻碍抗性育种，而晚熟在某些生产环境中可能是不理想的。本研究旨在鉴定与II型小麦赤霉病抗性（赤霉病严重程度，FHBS）相关的QTL，并确定它们是否与开花天数（DTA）、小穗数（NOS）以及芒的有无相关。2002年和2003年在温室中通过点接种对抗性品种Ernie和感病亲本MO 94 - 317杂交产生的243个F(8)重组自交系进行II型小麦赤霉病抗性表型分析。利用94个简单序列重复（SSR）标记和146个扩增片段长度多态性（AFLP）标记构建遗传连锁图谱。多年来，2B、3B、4BL和5A染色体上的4个QTL区域一直与小麦赤霉病抗性相关。这些QTL解释了FHBS中43.3%的表型变异。在2D染色体上鉴定出了控制DTA和NOS的主要QTL。与DTA和NOS相关的QTL以及芒的有无均与Ernie的小麦赤霉病抗性无关。我们的结果表明，Ernie的小麦赤霉病抗性似乎与苏麦3号不同，因此将Ernie中的QTL与苏麦3号中的QTL聚合可能会提高小麦的小麦赤霉病抗性水平。
