小麦-黑麦易位系T1BL1RS在小麦品种中的分布及其与小麦赤霉病抗性的关联

摘要

The short arm of 1R chromosome (1RS) of rye carries resistant genes to stripe rust, leaf rust, stem rust, powdery mil-dew and aphids. To understand if 1RS also mediates resistance to wheat Fusarium head blight (FHB), we genotyped a panel of 192 wheat accessions from diverse geographic regions and a population of recombinant inbred lines (RIL) consisting of 184 lines developed from the cross of Ning 7840 and Chokwang by 1RS-specific molecular marker Xscm9 and evaluated FHB severities in three consecutive seasons in greenhouses using single floret inoculation method. The results demonstrated that 22 of 192 acces-sions carried a T1BL×1RS translocation, and the mean FHB severity (PSS) of varieties carrying T1BL×1RS translocation was sig-nificantly lower than that of lines without the translocation across the three experiments (P<0.05), indicating 1RS may have a positive effect on reducing FHB severity. 1RS-specific marker Xscm9 and Genome in situ hybridization (GISH) showed Ning 7840 carries T1BL×1RS translocation. In the population of RILs, irrespective of Fhb1 locus, the mean PSS of lines with T1BL×1RS translocation was significantly lower than that of those lines without T1BL×1RS. The effects of Fhb1 and 1RS on FHB resistance were additive and the interactions between them were not significant (P=0.48). The results of this study suggested that 1RS of rye most likely carries the genes resistant to FHB.%黑麦1R染色体短臂(1RS)携带条锈病、叶锈病、秆锈病、白粉病和蚜虫等抗性基因。为了检测1RS上是否携带与赤霉病抗性相关的基因,本研究采用1RS特异标记Xscm9对192个来自不同国家的品种/系构成的小麦自然群体和1个重组自交系(RIL)群体(宁7840与Chokwang杂交的F7群体,共184个系)进行了分子检测,并在2011—2013年采用单花滴注法于温室中进行赤霉病抗性鉴定。结果发现,自然群体中22个品种携带1RS,携带1RS的株系三季赤霉病平均病小穗率(PSS)均显著低于不携带1RS株系的PSS (P<0.01),表明1RS对降低病小穗率有显著作用。分子标记和基因组原位杂交(GISH)检测结果表明,宁7840携带1RS。通过对宁7840/Chokwang衍生的RIL群体进行赤霉病抗性鉴定和基因型分析,发现不论主效赤霉病抗性基因Fhb1(标记Xsts142)存在与否,携带1RS株系的PSS显著低于不携带1RS株系的PSS (P<0.01)；方差分析表明,宁7840携带的Fhb1与1RS在赤霉病抗扩展性上无显著互作(P>0.05)。因此认为,黑麦1RS染色体很可能携带赤霉病扩展抗性相关基因,与Fhb1基因有累加效应。