论文部分内容阅读
【目的】获得与苦瓜抗白粉病基因紧密连锁的分子标记,为加快苦瓜抗白粉病新品种的选育奠定基础。【方法】以高抗白粉病野生苦瓜MC18为父本、高感白粉病苦瓜栽培种MC1-2为母本创建F2代分离群体;经单株抗病性鉴定后,以BSA法构建F2代单株的高抗和高感白粉病苦瓜DNA近等基因池;利用SRAP技术筛选多态扩增片段,对仅在抗白粉病近等基因池和父本中出现的差异片段进行回收、测序、比对和转化成SCAR标记,并利用已知抗病性的单株DNA分析标记与苦瓜抗白粉病的相关性。【结果】从1188对SRAP引物组合中筛选到稳定阳性差异条带的引物组合5对,其中ME20EM5引物对扩增的差异条带长度为332 bp,与葡萄抗体蛋白基因(抗性基因)的DNA序列有较高相似性,并将其成功转化成与苦瓜白粉病抗性相关、大小为320 bp的SCAR标记。【结论】开发的SCAR-ME20EM5分子标记可用于苦瓜抗白粉病分子标记辅助选择。
【Objective】 Molecular markers closely linked to powdery mildew resistance gene of powdery mildew were obtained, which laid the foundation for accelerating the selection of new varieties of powdery mildew resistant to powdery mildew. 【Method】 F2 generation segregation population was established with high resistance to powdery mildew wild bitter melon MC18 as male parent and bitter melon cultivar MC1-2 with high susceptibility to powdery mildew. After single-disease resistance identification, F2 generation single Strains of high resistance and susceptibility to powdery mildew DNA near isogenic pool; using SRAP screening of polymorphic amplified fragments, only resistant to powdery mildew near isogenic pool and paternal differential fragments recovered, sequencing, than Pairs and transformed into SCAR markers, and the use of single plant DNA known to be disease-resistant was analyzed for marker-related resistance to bitter melon powdery mildew. 【Result】 Five pairs of primer combinations were screened from 1188 pairs of SRAP primer combinations. The length of the differential bands amplified by ME20EM5 primer pair was 332 bp, which was close to that of grape protein gene (resistance gene) The sequence was highly similar and was successfully transformed into a SCAR marker with a size of 320 bp, which was related to powdery mildew resistance of bitter melon. 【Conclusion】 The developed SCAR-ME20EM5 molecular marker can be used for molecular marker-assisted selection of bitter melon-resistant powdery mildew.