基于BSA-Seq技术的甜瓜抗霜霉病InDel标记开发

目的 获得与甜瓜抗霜霉病基因连锁的分子标记或功能标记,用于甜瓜分子标记辅助选择育种。为进一步克隆甜瓜抗霜霉病主效基因奠定基础。方法 以野生高抗霜霉病资源DM-4和感病自交系DM-2为亲本,构建F₂代分离群体,利用BSA-seq对甜瓜抗霜霉基因进行QTL定位,开发InDel分子标记,并在双亲及其F₂群体单株进行筛选验证。结果 甜瓜抗霜霉病主效QTL位于第9号染色体。在候选区间开发了37个InDel分子标记,有9个PCR产物大小在抗、感双亲表现出差异,用F₂单株验证,结合田间表型鉴定结果,引物InDel 15和InDel 20准确率分别为95 %和98 %,引物InDel 15和InDel 20在抗病亲本中扩增产物大小分别为251和349 bp,在感病亲本中分别为231和324 bp。结论 引物InDel 15和InDel 20可以作为分子标记进行抗霜霉病辅助选育,加快了甜瓜抗霜霉病育种速度。

Development of InDel Marker for Melon Resistance to Downy Mildew Based on BSA Resequencing

【Objective】 o obtain molecular markers of melon downy mildew resistance genes, and improve the accuracy and scientific city of melon downy mildew resistance traits selection. 【Methods】 The F₂ generation segregation population was constructed by hybridization between wild high-resistant downy mildew resource DM-4 and susceptible inbred line DM-2BSA-seq was used to locate and regulate the candidate interval of downy mildew resistance gene in melon InDel molecular markers. parents and their F₂ individuals were used for screening and verification.【Results】 Genes regulating melon downy mildew resistance are located on 9th chromosome. 37 InDel molecular markers were developed in the candidate region, and 9 of them showed differences in the size of PCR products between resistant and susceptible parents. Further verification was carried out with F₂ plants. Combined with field phenotypic identification results, the accuracy rates of primer InDel 15 and InDel 20 were 95 % and 98 %, respectively. The amplified products of primer InDel 15 and InDel 20 in resistant parents were 251 bp and 349 bp, respectively, and 231 bp and 324 bp, respectively.【Conclusion】 Primers InDel 15 and InDel 20 can be used as molecular markers for downy mildew resistance breeding, which can accelerate the breeding speed of melon downy mildew resistance and lay the foundation for further cloning the main genes of melon downy mildew resistance.