Among the various biotic stresses limiting sunflower productivity, powdery mildew incited by has become a serious problem in the tropical regions. Reliable source of resistance has been identified in the diploid annual wild species (PRA-1823). Interspecific cross of cultivated sunflower (Acc. PS-2023) with PRA-1823 was advanced to develop interspecific recombinant inbred lines (IRILs) with distinct phenotypic reaction to the pathogen. The IRILs with similar morphology were subjected to molecular analysis by adopting the bulk pooling analysis (BPA) wherein DNA of eight each of susceptible and resistant IRILs were pooled to constitute the respective bulks. Fourteen sunflower specific SSR markers that showed polymorphism between the susceptible and resistant bulk IRILs, discriminated the powdery mildew resistant and susceptible samples as well. The primer ORS 485 was dominant and showed amplification only in the susceptible bulks and accessions and hence, it was converted to a multiplex reaction with actin to overrule the possibility of PCR failure. These 14 primers were successfully validated on IRIL populations and individual plants, a set of 40 breeding lines and 205 germplasm accessions with high susceptibility to the pathogen, 11 species and three previously reported sources of resistance to powdery mildew (PM-81, IR-6, TX-16 R). This constitutes the first successful attempt at development of a diagnostic molecular marker set for distinguishing the powdery mildew resistant and susceptible genotypes in sunflower.

中文翻译：

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开发向日葵（Helianthus annuus L.）白粉病抗性表型并诊断对Golovinomyces latisporus反应的新策略

在限制向日葵生产力的各种生物胁迫中，白粉病引起的白粉病已成为热带地区的一个严重问题。可靠的抗性来源已在二倍体一年生野生物种 (PRA-1823) 中确定。培育的向日葵 (Acc. PS-2023) 与 PRA-1823 进行种间杂交，以开发对病原体具有不同表型反应的种间重组自交系 (IRIL)。通过采用批量合并分析(BPA)对具有相似形态的IRIL进行分子分析，其中将易感IRIL和抗性IRIL各8个的DNA合并以构成各自的批量。 14 个向日葵特异性 SSR 标记显示了易感和抗性大量 IRIL 之间的多态性，也区分了白粉病抗性和易感样品。引物 ORS 485 占主导地位，仅在易受影响的批次和种质中显示扩增，因此，将其转换为与肌动蛋白的多重反应，以排除 PCR 失败的可能性。这 14 个引物在 IRIL 群体和个体植物、一组 40 个育种系和 205 个对病原体高度易感性的种质材料、11 个物种和 3 个先前报告的白粉病抗性来源（PM-81、IR-6）上成功进行了验证。 ，TX-16 R）。这是开发用于区分向日葵白粉病抗性和易感基因型的诊断分子标记集的首次成功尝试。