小麦抗赤霉病主效QTL的聚合效应分析

Analysis of Pyramiding Effect of Major QTLs for Resistance to Scab in Wheat

为了明确小麦抗赤霉病主效QTL的抗病效应,基于分子标记辅助选择,将来源于抗病品种苏麦3号的Fhb1、Fhb2和望水白的Fhb4、Fhb5回交导入感病品种矮抗58中,构建出30个不同QTL组合的株系,分别采用单花滴注和喷洒孢子悬浮液接种法,对其开展抗侵入、抗扩展和综合抗性鉴定。结果表明,携带Fhb1和Fhb2的株系表现出显著的抗扩展能力,Fhb1的效应显著高于Fhb2,但二者都没有抗侵入效应;携带Fhb4和Fhb5的株系表现出明显的抗侵入性,二者累加后效应更显著,但均没有明显的抗扩展能力;不同抗性类型的QTL聚合后,其综合抗病性比单个QTL更显著。说明在育种中,将不同抗性类型的QTL聚合后比单个QTL的抗赤霉病效果更佳。

In order to clarify the wheat scab resistance effect of major QTLs,four major QTLs were backcrossed into susceptible variety Aikang 58 based on molecular marker assisted selection, and 30 different combinations of QTL were conducted,which were used for inoculation,resistance to expan- sion and comprehensive resistance identification by single floret inoculation and spraying spores inocu- lation, respectively. Among them, Fhbl andFhb2 are derived from Sumai 3, andFhb4 andFhb5 are o- riginated from Wangshuibai. The results showed that the lines containingFhbl and Fhb2 performed significant resistance to expansion,and the effect of Fhbl was significantly higher than that of Fhb2, but neither of them had anti-penetration effect. The lines with Fhb4 and Fhb5 presented obvious re- sistance to penetration, and the cumulative effect of them was more remarkable than that of individual Fhb4 orFhb5,but there was no obvious ability to anti-expansion effect. The lines with different resistance types of QTLs had more comprehensive resistance than those with any single resistance type of QTL. Therefore,pyramiding different resistance types of QTLs is more effective than single QTL for scab resistance in wheat breeding practice.