小麦中与低脱氧雪腐镰刀菌烯醇含量关联的抗性基因类似物

脱氧雪腐镰刀菌烯醇(Deoxynivalenol,DON)是小麦遭受赤霉病危害后由赤霉病菌———禾谷镰刀菌产生的一种真菌毒素,这种毒素对人类和家畜的健康产生危害,严重地影响小麦的利用价值.种植低DON含量的品种是减少这种毒素危害的有效措施,而分子标记辅助育种技术能加速低DON品种的选育进程.在采用AFLP、SSR分子标记的基础上,进一步利用抗性基因类似物(RGA)对‘宁7840’(低DON含量的品种)和‘Clark’(高DON含量的品种)建立的133个重组自交系进行了DON含量的遗传特性分析.研究结果发现两个DON含量的数量特性位点(QTL),它们中含有4个与低DON含量密切相关RGAs,其中三个RGAs(RGA14-1,RGA16-1,RGA18-1)座落在染色体1A的长臂上,另一个(RGA14-2)座落在染色体5B的长臂上.座落在1AL和5BL上的QTL分别解释16.81%和7.84%的DON含量变异.DNA序列分析表明这些RGAs均与现已发现的抗性基因同源/类似,它们可能在小麦的低DON含量和赤霉病抗性上扮演着重要的角色.

Resistance gene analogs associated with low Deoxynivalenol level in wheat

Deoxynivalenol(DON) is a type of harmful mycotoxin produced by Fusarium graminearum Schwabe(teleomorph Gibberella zeae(Schwein) Petch) when fusarium head blight(FHB) is epidemic in wheat.DON contamination in harvested grain can significantly lower market grade,and result in significant discount in price to the farmers.Growing resistant cultivars containing none or low levels of DON is the most effective measure to reduce the losses,while molecular markers for low DON levels may provide a shortcut for selecting wheat genotypes with low DON.On the basis of AFLPs and SSRs,resistance gene analogs(RGAs) were further used to analyze the genetic characteristics of DON level in wheat through 133 recombinant inbred lines(RILs) derived from the cross of Ning7840(low DON level) and Clark(high DON level).Two QTLs(quantitative trait loci) with RGAs were identified,these RGAs were highly associated with low DON level,three of them(RGA14-1,RGA16-1 and RGA18-1) were located on chromosome 1AL,another was located on chromosome 5BL.These QTLs explained 16.81% and 7.84% phenotypic variance of DON level,respectively.The analysis of DNA sequence revealed all of these RGAs were similar/homologous with resistance genes,and may play important roles in low DON level and FHB resistance.