利用SNP芯片构建甘蓝型油菜高密度遗传连锁图谱及含油量性状QTL分析

High-density Genetic Linkage and Oil Content Trait QTL Mapping in Brassica napus L. Using SNP Array

【目的】在云南生境下挖掘甘蓝型油菜含油量QTL位点,为高含油量性状遗传机制研究和分子标记辅助高含油量育种提供理论基础。【方法】以高含油量材料G28为母本,低含油量材料H008为父本,通过小孢子培养技术创建包含175份株系的F1 DH群体,利用60K SNP芯片构建高密度遗传连锁图谱,结合2016-2017年丽江与临沧点DH群体含油量数据采用完备区间作图法,以LOD=2.5为阈值扫描含油量性状QTL。【结果】DH群体含油量性状呈现正态分布,表现出单向超亲分离。2个环境下共检测到6个含油量QTL,分别可解释6.29%~10.36%的表型变异。通过Blast分析将这6个QTL分别映射到参考基因组-Darmor-bzh ChrA01,ChrA10,ChrC05与ChrC08染色体物理图谱上。与前人研究比较分析推测位于C05染色体上的qOCc05.1与qOCc05.2为新的含油量性状相关的QTL。【结论】在云南生境下检测到6个含油量性状QTL并明确了其在染色体的物理区间,定位结果可用于下一步主效QTL的精细定位和分子标记辅助高含油量油菜育种。

【Objective】Promoting oil content is an important target in rape breeding.Mining QTLs associated with oil content trait facilitate the study on genetic mechanism of oil content and developing molecular markers for high oil content breeding in Brassica napus.【Method】The high density genetic linkage map was constructed by using 60 K SNP mapping array with 175 F1 DH lines derived from a cross of an high oil content inbred line,G28 and low oil content inbred line,H008.The oil content data of DH lines and parental material were obtained from Lincang and Lijiang in 2016-2017 plant seasons.The method of Inclusive Composite Interval Mapping(ICIM)was employed to carry out QTL analysis for oil content trait with LOD value 2.5.【Result】The oil content data of DH showed normal distribution.Six QTLs of oil content trait,qOCa01.1,qOCa10.1,qOCc05.1,qOCc08.1,qOCa10.2 and qOCc05.2,were detected in two growing conditions and reflected to the reference genome by Blast analysis.Compared with previous report it suggested that qOCc05.1 and qOCc05.2,both located on chromosome C05,might be the new QTLs related with oil content trait.【Conclusion】Six oil content QTLs were detected by genetic linkage mapping and their physical interval were mapped on reference genome,which would be helpful for fine mapping the major QTL and high oil content rape breeding in the future.