利用重组自交系群体定位不同温度条件下玉米种子发芽性状的QTL

QTL Mapping of Seed Germination Traits under Different Temperature Conditions Using Recombinant Inbred Lines of Maize

以基于豫82×沈137和豫537A×沈137构建的2个重组自交系群体的420个家系为材料,借助SNP分子标记遗传连锁图谱,利用复合区间作图法定位了发芽率(GP)、发芽势(GE)、发芽指数(GI)、活力指数(VI)、苗长(SL)、幼苗干质量(SDW)、根干质量(RDW)7个种子发芽相关性状的QTL。结果表明,基于豫82×沈137的重组自交系群体检测到24个QTLs,分布在1、2、3、5、6、7、10染色体上,单个QTL解释性状遗传变异的5.61%~11.01%;基于豫537A×沈137的重组自交系群体检测到40个QTLs,分布在除第2染色体外的其余9条染色体上,单个QTL解释性状遗传变异的5.39%~11.92%。通过元分析方法将64个原初QTLs中的25个(39.1%)整合进6个mQTLs,分别分布于第3、5、7、10染色体上,每个mQTL平均包含4.17个QTLs,分别参与2~4个性状的调控,其中,mQTL3-2包含了7个QTLs,参与对VI、SDW、RDW、GE等4个性状的调控。确定了位于6个mQTLs对应标记区间的35个候选基因,主要参与种子萌发、氧化还原代谢途径、信号传导、逆境抵御等生物学过程。

Two recombinant inbred lines（ RILs） populations which were obtained from Yu 537 A × Shen137 and Yu 82 × Shen 137 and contained 420 family lines were used as materials,two high-density molecular linkage maps were constructed using single nucleotide polymorphism（ SNP） molecular marker technology. Through composite interval mapping method,the QTLs of seed vigor-related morphological and physiological traits were detected,including percentage of germination（ GP）,germination energy（ GE）,germination index（ GI）,vigor index（ VI）,seedling length（ SL）,seedling dry weight（ SDW）,root dry weight（ RDW）. Sixty-four QTLs for seed vigor-related traits were detected in the two connected RILs population in normal and low temperature conditions. The results showed that twenty-four QTLs were found inthe population based on Yu 82 × Shen 137,and were located on chromosomes 1,2,3,4,5,6,7 and 10,with the explanation of phenotypic variation of a single QTL from 5. 61% to 11. 01%. Others fourty QTLs were found in the population based on Yu 537 A × Shen 137,and located on all chromosomes except 2,with the explanation of phenotypic variation of a single QTL from 5. 39% to 11. 92%. Six mQTLs were identified on chromosomes 3,5,7 and 10 by meta-analysis,and twenty-five initial QTLs were integrated,the consolidation ratio was 39. 1%. Each mQTL contained 4. 17 QTLs on average,involved in the regulation of two to four traits,including VI,SDW,RDW,GE,mQTL3-2 contained 7 QTLs. Thirty-five candidate genes were located in 6 mQTLs corresponding SNP marker distribution ranges,which involved in the regulation of seed germination,plant development,growth metabolic pathways,signal transduction,withstanding adversity and so forth.