控制黄瓜白绿色果皮基因w的定位和候选基因预测  

Mapping and prediction of candidate gene w controlling white-green fruit color in cucumber

作　　者：杨康 宋蒙飞 魏庆镇 王晶[1] 陈劲枫[1] 娄群峰[1] YANG Kang;SONG Mengfei;WEI Qingzhen;WANG Jing;CHEN Jinfeng;LOU Qunfeng(State Key Laboratory of Crop Genetics and Germplasm Enhancement/College of Horticulture, Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学作物遗传与种质创新国家重点实验室/园艺学院,江苏南京210095

出　　处：《南京农业大学学报》2018年第6期1003-1008,共6页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(31772318);国家重点研发计划项目子课题(2016YFD0100204-25);江苏省农业科技自主创新项目[CX(17)3016];江苏高校"青蓝工程"人才项目

摘　　要：[目的]本文旨在通过对黄瓜白绿色果皮性状的研究,为果实性状相关的调控机制以及品种改良提供指导。[方法]以果皮颜色为白绿色的黄瓜自然突变体为材料,与野生型绿色果皮材料杂交、自交构建F2群体,在生理和遗传分析的基础上,利用集群分离分析法(BSA)结合重测序(BSA-seq)的方法来定位控制黄瓜白绿果皮的基因,并通过基因注释、RT-qPCR等方法来验证候选基因。[结果]色素含量分析表明,突变体果皮中叶绿素a和叶绿素b含量均显著低于绿色果实果皮中的含量。遗传分析表明,该白绿色果皮是由单基因控制的隐性性状。BSA-seq分析将候选基因定位于黄瓜3号染色体35.50～37.77 Mb和38.21～39.71 Mb。通过序列比对发现,在2个材料中有5个基因存在Indel的多态性。进一步通过基因表达分析显示,在果实的生长发育过程中,Csa3G904140基因在绿色果实中的表达水平明显高于白绿色果实。在白绿色突变体3号染色体Csa3G904140基因上1个单核苷酸插入造成终止密码子提前,导致101氨基酸残基的缺失。综合分析确定Csa3G904140是控制黄瓜白绿色果实颜色的候选基因。[结论]利用BSA和基因组重测序相结合的方法成功定位了控制黄瓜果实白绿色果皮的基因。[Objectives]Fruit related traits are the important target traits of variety improvement,and the fruit color is an important feature.The identification of genes controlling fruit color can provide guidance for the improvement of the fruit character.[Methods]A natural white-green fruit color mutant was crossed with the wild type green fruit color material,to construct F 2 population.Then after physiological and genetic analysis,the method of bulked segregant analysis(BSA)combining with resequencing BSA-seq was employed to map the corresponding genes controlling the white-green fruit color.Further,gene annotation and RT-qPCR were applied to verify the candidate gene.[Results]The pigment content analysis result showed that the contents of chlorophyll a and chlorophyll b in the white-green fruit peel was significantly lower than that in the green fruit peel.Genetic analysis result showed that the white-green fruit color was a recessive trait controlled by a single gene.BSA-seq results showed that the candidate genes were mapped on the regions of 35.50-37.77 Mb and 38.21-39.71 Mb on chromosome 3.Sequence alignment results revealed that there are five Indel polymorphic gene loci between two materials.Further,the expression analysis showed that the expression level of Csa 3G904140 gene in green fruit was obviously higher than that of white green fruit during the growth of fruit.And a single nucleotide insertion in Csa 3G904140 gene in white-green material caused the termination of codon,resulting in the deletion of 101 amino acid residues in the gene.Based on these results,Csa 3G904140 was identified as a candidate gene controlling the color of white-green fruit of cucumber.[Conclusions]The gene for controlling the white green fruit peel of cucumber fruit was successfully located by the combination of BSA and genome sequencing.

关 键 词：黄瓜 果皮颜色 突变体 集群分离分析法 高通量测序 基因定位 

分 类 号：S642.2[农业科学—蔬菜学]