A major QTL conferring crown rot resistance in barley and its association with plant height
A major QTL conferring crown rot resistance in barley and its association with plant height
复制标题
DOI：
10.1007/s00122-008-0948-3
复制
发表时间：
2009-03-01
影响因子：
5.4
通讯作者：
Liu, C. J.
中科院分区：
文献类型：
--
作者：
Li, H. B.;Zhou, M. X.;Liu, C. J.
大麦和小麦冠腐病是危害最大的病害之一。引起作物根腐病的镰刀菌在作物残留物中存活，人们越来越多地接受留茬做法，这加剧了疾病的严重性和产量损失。长期以来，种植抗病品种一直被认为是减少CR危害的最有效方法，但大麦中没有这种方法。在常规种质筛选中，来自中国的大麦地方品种在供试的大麦品种中表现出最好的抗逆性。利用这个地方品种与富兰克林杂交的加倍单倍体群体，我们证明了TX9425对CR的抗性是由一个主QTL控制的。该QTL定位于染色体长臂着丝粒附近，命名为Qcrs.cpi-3H。其效应显著，对表型变异的贡献率高达63.3%，LOD值为14.8。Qcrs.cpi-3H的定位与一个控制株高的主效QTL相吻合，而且PH对CR反应的影响也是极显著的。当用协方差分析来解释PH的影响时，Qcrs.cpi-3HQTL对表型变异的贡献率仍达40%以上。这样一个主效QTL的存在，说明选育抗逆性较强的大麦品种是可行的。
Crown rot (CR) is one of the most destructive diseases of barley and wheat. Fusarium species causing CR survive in crop residue and a growing acceptance of stubble retention practices has exacerbated disease severity and yield loss. Growing resistant cultivars has long been recognised as the most effective way to reduce CR damage but these are not available in barley. In a routine screening of germplasm, a barley landrace from China gave the best CR resistance among the genotypes tested. Using a doubled haploid population derived from this landrace crossed to Franklin, we demonstrate that the CR resistance of TX9425 was conditioned by a major QTL. The QTL, designated as Qcrs.cpi-3H, was mapped near the centromere on the long arm of chromosome 3H. Its effect is highly significant, accounting for up to 63.3% of the phenotypic variation with a LOD value of 14.8. The location of Qcrs.cpi-3H was coincident with a major QTL conferring plant height (PH) and the effect of PH on CR reaction was also highly significant. When the effect of PH was accounted for by covariance analysis, the Qcrs.cpi-3H QTL remained highly significant, accounting for over 40% of the phenotypic variation. The existence of such a major QTL implies that breeding barley cultivars with enhanced CR resistance should be feasible.