中文摘要：

以甜瓜高抗白粉病自交系MR-1为母本，易感白粉病自交系TopMark为父本，构建BC1P2和F2群体，经13个国际通用的甜瓜白粉病生理小种鉴别寄主鉴定，2015年东北农业大学设施园艺工程中心的白粉病发病病菌为P.xanthii生理小种1，甜瓜MR-1对P.xanthii生理小种1的抗性由单显性基因控制。通过对266个F2分离群体的抗病性鉴定和CAPS标记分析，采用复合区间作图法对甜瓜抗白粉病性状进行QTL分析，最终构建了1张包含203个CAPS标记的甜瓜遗传连锁图谱，并将抗病基因PXR定位在第12号染色体上M12-GH和M12-TE2个标记之间，该基因与两侧翼标记间的距离分别为0.63cM和0.42cM，两侧翼标记间在甜瓜参考基因组上对应的物理距离为303kb，该区域内含有60个预测基因，其中10个基因含有非同义单碱基突变。10个基因荧光定量分析结果显示，在抗病与感病甜瓜表达量存在较大差异的4个基因MELO3C002434、MELO3C002437、MELO3C002441、MELO3C002457为甜瓜白粉病抗病候选基因。

英文摘要：

BC1P2and F2generations were constructed by crossing a melon inbred line‘MR-1’highlyresistant to powdery mildew(Podosphaera xanthii)as female parent,and a melon inbred line‘Top Mark’highly susceptible to powdery mildew as male parent.The race of P.xanthii was identified as race1according to the infecting action of13international differential hosts for melon powdery mildew,and the resistance to powdery mildew was controlled by a single dominant gene based on the population genetic analysis of BC1P2and F2.Through evaluating the resistance in266individuals of F2,the genotype analysis using cleaved amplified polymorphic sequences(CAPS),and quantitative trait loci(QTL)analysis using composite interval mapping method(CIM)for locating the locus resistant to powdery mildew,a genetic linkage map of melon contained203CAPS was constructed.One QTL named PXR was detected on chromosome12between the2CAPS markers,M12-GH and M12-TE,which were tightly linked to the gene resistant to powdery mildew with the genetic distances of0.63cM and0.42cM,respectively.Sixty putative genes were located in the region with the length of303kb between the2flanking markers.Ten of them with non-synonymous single nucleotide polymorphism(nsSNP)were further identified as candidate genes resistant to powdery mildew in melon.The results suggested that4genes(MELO3C002434,MELO3C002437,MELO3C002441,and MELO3C002457)showed bigger differences in expression of disease resistance and susceptible might be the candidate genes resistant to powdery mildew in melon.