黄瓜果顶形状遗传与QTL定位

Inheritance and QTL mapping of fruit apex shape in cucumber

对黄瓜果顶形状进行QTL分析和候选基因预测,可为黄瓜新品种选育提供理论基础。以果顶平头形自交系玉女和果顶瘦尖形自交系R7构建的F2代分离群体为材料,对黄瓜果顶形状遗传及其QTL进行分析。结果表明,黄瓜果顶瘦尖形为不完全显性遗传的数量性状。基于QTL-Seq发现6个与黄瓜果顶形状有关的QTL,分别位于1号、2号、3号、4号、5号和6号染色体上,共包含108个SNP和InDel位点,含有12个变异基因。其中只有6号染色体上的CsaV3_6G005930.1基因在外显子上发生SNP替换(C-A)形成终止密码子,导致翻译提前终止,预测CsaV3_6G005930.1是与果顶形状相关的候选基因,该基因编码一个未知蛋白。

QTL analysis and candidate genes prediction of the fruit apex shape can provide a theoretical foundation for the breeding of new cucumber varieties.In this study,the genetic and QTL of fruit apex shape were analyzed by using F2 population which was constructed with an inbred line of flat fruit apex Yunü(P1)and an inbred line of sharp fruit apex R7(P2)as parents.Genetic analysis showed that the fruit sharp apex of cucumber was a quantitative character with incomplete dominant inheritance.Six QTLs related to fruitapex shape of cucumber were located on chromosome 1,chromosome 2,chromosome 3,chromosome 4,chromosome 5 and chromosome 6 by QTL-Seq,respectively.A total of 108 SNP and InDel locus which related to the fruit apex shape were located,contained 12 mutation genes.Only the CsaV3_6G005930.1 gene on chromosome 6 happened a SNP replacement(C-A)to form the termination codon,and resulted in premature termination of translation.Therefore,CsaV3_6G005930.1 is a strong candidate gene for fruit apex shape,which encodes an unknown protein.