利用相同来源F2:3和BC2S1群体定位玉米生育期QTL

以普通玉米自交系丹232和爆裂玉米自交系N04为亲本构建259个F2:3和220个BC2S1家系群体,利用SSR标记构建分子标记遗传图谱,利用复合区间作图方法对4个生育期性状进行QTL定位和效应分析。利用F2:3群体共检测到4个抽雄期QTL、6个吐丝期QTL和3个散粉期QTL。单个QTL可解释的表型变异为6.7%~18.4%,可解释的表型总变异为28.9%~50.3%,11个QTL的增效基因来自生育期较长的亲本丹232,其余2个QTL的增效基因来自生育期较短的亲本N04;BC2S1群体检测到8个与4个生育期性状相关的QTL,单个QTL可解释的表型变异为4.5%~11.6%,可解释的表型总变异为13.2%~18.5%,增效基因来自两个亲本的QTL为3个和5个。两类群体检测出QTL的数目、位置、效应和贡献率均存在较大差异,主要原因在于BC2S1群体抽样选择所引起的群体结构差异,F2:3群体显示出较高的QTL检测能力,但回交育种过程中应慎重依据F2:3群体QTL定位结果进行标记辅助选择(MAS)。

QTL Mapping of Developmental Stages Using F2:3 and BC2S1 Populations Derived from the Same Cross in Maize

Two hundred and fifty-nine F2:3 and 220 BC2S1 families,derived from the same cross between Dan232,a dent corn inbred and N04,a popcorn inbred,were evaluated for four developmental stages,tassel emergence,male anthesis,silk emergence and days from male anthesis to silk emergence(ASI).Quantative trait loci(QTL)were identified and their effects were evaluated using composite interval mapping(CIM)method.A total of 13 QTL were detected in the F2:3 population,the numbers of QTL were 4,6 and 3 for tassel emergence,male anthesis and silk emergence,respectively.Contribution to phenotypic variation of a single QTL varied from 6.7% to 18.4%,and total contributions of all QTL were from 28.9% to 50.3 %.The favorable alleles of 11 QTL were from Dan232,the parent with much longer developmental stages,while the favorable alleles of other two QTL were from N04,the parent with much shorter developmental stages.In the BC2S1 population,eight QTL were detected totally,all two for each developmental stage.Contribution to phenotypic variation of a single QTL varied from 4.5% to 11.6%,and total contributions of all QTL were from 13.2% to 18.5%.The favorable alleles of three and five QTL were contributed by the two parents,respectively.There were obvious differences between the two populations in numbers of detected QTL and their positions,effects and contributions.The main reason might be attributed to their different population structures due to strict selections while developing the BC2S1 population.Although F2:3 population had higher ability in QTL identification,it should be taken great consideration to conduct MAS in backcross breeding according to the QTL mapping results in F2:3 populations.