【摘要】 西瓜枯萎病是由尖孢镰刀菌西瓜专化型（Fusarium oxysporumf. sp.niveum）引起的土传真菌病害,是西瓜生产的限制因子。本研究以西瓜抗病种质“V13-9-3”和感病种质“W16-1”为亲本,构建了“W16-1”דV13-9-3”的F₁、F₂群体。苗期人工接种结果显示:F₁植株表现抗病,F₂群体的抗病∶感病分离比为3∶1,表明西瓜枯萎病生理小种1的抗性遗传受显性单基因控制。利用BSA技术,采用SNP指数和In Del指数法,将西瓜抗枯萎病基因Fon-1定位在1号染色体上2.20 Mb和2.32 Mb区域内,将这2种方法的定位结果取交集,最终将目标抗病基因区域缩小在2.20 Mb之内,该区域包含8个非同义突变基因和1个移码突变基因。利用荧光定量PCR检测这9个突变基因在接种枯萎病菌5 d和10 d后的表达量变化,发现抗病亲本“V13-9-3”中有7个基因的表达量显著高于感病亲本“W16-1”。研究通过结合SNP指数和In Del指数分析可以快速进行基因初定位,为西瓜抗枯萎病的分子机理研究提供理论依据。更多还原

【Abstract】 Watermelon Fusarium wilt, a worldwide soil borne fungal disease, is caused byFusarium oxysporumf. sp.niveumand can dramatically reduce the watermelon yield. In this study,the resistant watermelongermplasm “V13-9-3” and the susceptible germplasm “W16-1” were used as parents to construct F1and F2populations. The F1population showed resistance to Fusarium wilt,while the F2population had a 3∶ 1 segregationratio of resistance and susceptibility. It demonstrated that the resistance againstF. oxysporumf. sp.niveumrace 1was controlled by a single dominant gene.Fon-1 was found to be localized to 2. 20 Mb and 2. 32 Mb onchromosome 1 by single nucleotide polymorphism( SNP) and insertion deletion( In Del) index methods. Afteraccounting for overlapping regions, the target region narrowed down to 2. 20 Mb. Reverse-transcriptionquantitative polymerase chain reaction analysis further confirmed the relative expression of genes,whereby theexpression of 7 genes in “V13-9-3” was significantly higher than that in “W16-1” at 5 dpi or 10 dpi. This studyproposed a novel combinatorial strategy by combining the SNP and In Del index analyses. This approach allowedrapid mapping of the genes responsible for specific traits and provides a robust base for cloning theFon-1 gene.更多还原