Sources of resistance to powdery mildew incited by Golovinomyces orontii have been identified in wild sunflowers and few exotic lines. The present investigation has been undertaken to study the inheritance of powdery mildew resistance and to map the quantitative trait loci (QTLs) governing resistance to powdery mildew in a multiple disease resistance line, TX16R (PI 642072). The inheritance was observed as a continuous distribution in a set of 264 F2 population and 93 recombinant inbred lines (RILs) of a cross between a highly susceptible accession PS 2023 and TX16R. Screening of the two population sets was done with 484 sunflower-specific SSR primers of which 175 primers showed polymorphism between the parents. Based on the phenotyping and genotyping data, the linkage map was constructed with 93 RILs. The map spanned 1200 cM and included 64 markers distributed along the 17 sunflower chromosomes in the haploid set. Quantitative trait loci (QTL) analysis identified three genomic regions for resistance to powdery mildew, two of which mapped on chromosome 10 and one on chromosome 5. This is the first report on mapping of powdery mildew resistance in sunflower and paves the way in fine mapping and introgression of resistance for powdery mildew in sunflower through marker-assisted breeding.

中文翻译：

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向日葵（Helianthus annuus L.）白粉病（Golovinomyces orontii）抗性基因的遗传和分子作图。

在野生向日葵和极少数外来品系中已经发现了由戈氏菌引起的抗白粉病的来源。进行了本研究以研究白粉病抗性的遗传，并绘制了在多种疾病抗性系TX16R（PI 642072）中控制白粉病抗性的定量性状位点（QTL）。在一组264 F2种群和93个高度易感登录号PS 2023与TX16R之间的杂交的近交自交系（RIL）中，该遗传被观察为连续分布。用484株向日葵特有的SSR引物对这两个种群进行了筛选，其中175份引物显示出亲本之间的多态性。根据表型和基因型数据，用93个RIL构建了连锁图。该图跨度为1200 cM，包括沿单倍体组中的17个向日葵染色体分布的64个标记。数量性状基因座（QTL）分析确定了三个抗白粉病的基因组区域，其中两个定位在10号染色体上，一个位于5号染色体上。这是关于向日葵抗白粉病定位图谱的首次报道，为精细定位铺平了道路。标记辅助育种对向日葵白粉病的抗性和基因渗入