Powdery mildew,caused by Blumeria graminis f. sp. tritici,is one of the most important diseases of wheat (Triticum aestivum L. ) worldwide and causes severe yield losses. Breeding for resistance is the most economical and effective method for controlling the disease. The wheat breeding line CH5026 derived from the partial wheat-Thinopyrum intermedium amphiploid TAI7045 is resistant to powdery mildew. To determine inheritance of powdery mildew resistance and map the resistance gene(s) in CH5026,F_2 ,F_3, BC_1F_2 progenies derived from the crosses of CH5026 with line CH5065 and susceptible cv. Jintai 170 were inoculated with Bgt isolate E09 in the greenhouse. Genetic analysis indicated that a single dominant gene, temporarily designated PmCH5026, was responsible for the resistance to Bgt in line CH5026. A total of 378 SSR markers were used to test the parents and resistant and susceptible bulks from the F_2 segregating population of CH5026 × CH5065. From the bulked segregant analysis,the polymorphic SSR markers were selected for genotyping the F_2 population. Three SSR markers Xcfd233 , Xbarc11 and Xgwm539 were identified to be linked to the resistance gene and their most likely order was Xcfd233,7. 2 cM, PmCH5026, 4.9 cM, Xbarc11 , 5. 5 cM, Xgwm539. Using the Chinese Spring nullisomic-tetrasomic and ditelosomic lines,the SSR markers mapped the resistance gene on chromosome arm 2DL.%CH5026是衍生于八倍体小偃麦TAI7045的新品系,用高感品种(系)CH5065、晋太170分别与CH5026配置组合,于温室接种并调查F_2、F_3、BC_1F_2群体的抗感分离之比进行遗传分析,结果表明CH5026成株期对白粉菌E09小种的抗性受1对显性基因控制,暂命名为PmCH5026.使用集群分离分析法(BSA),用378对SSR引物对CH5026×CH5065 F_2代群体进行分析,筛选到标记Xcfd233、Xbarc11和Xgwm539与抗性基因连锁,位置顺序为:Xcfd233-7.2cM-PmCH5026-4.9cM-Xbarc11-5.5cM-Xgwm539.根据小麦微卫星遗传连锁图及利用中国春第2同源群缺四体、双端体对SSR标记的定位结果,将PmCH5026定位在染色体2DL上.
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