弱光胁迫下黄瓜幼苗下胚轴性状QTL分析

QTL Analysis for Hypocotyl Traits of Cucumber Seedlings Under Low Light Stress

用黄瓜耐弱光品系M22和弱光敏感品系M14杂交衍生的152个F2单株为作图群体,利用21个SSR多态性标记和135个SRAP多态性标记构建遗传图谱,结合2008年秋季和2009年春季弱光胁迫下123株F2:3家系(F2代单株衍生为F2:3的家系)的下胚轴性状进行QTL定位分析。结果在两季共检测到15个控制下胚轴性状的QTLs,贡献率在5.5%～19.8%,分别定位在LG1、LG2、LG4、LG6和LG7连锁群上。2008年秋季分别检测到6个控制下胚轴长和2个控制下胚轴粗的QTLs,总贡献率分别为58.2%和27.7%;2009年春季分别检测到4个控制下胚轴长和3个控制下胚轴粗的QTLs位点,总贡献率分别为34.6%和34.7%。

A linkage map of cucumber was constructed using 152 progenies of F2 generation derived from a cross between the low light stress tolerance line M22 and the low light sensitivity line M14 in the experiment.The effects of low light stress on the hypocotyl traits of cucumber were investigated in a set of 123 F2：3 lines in the seeding stage in the autumn of 2008 and spring of 2009.QTL analysis was undertaken on the basis of a genetic linkage map of the corresponding F2 population that was constructed using composite interval mapping.F2：3-based QTL analysis of the hypocotyl length and hypocotyl thick in the two environments revealed 15 QTLs were located in five linkage groups,i.e.,the 1st,2nd,4th,6th,and 7th,each accounted for 5.5%-19.8% of the phenotypic variation.In the autumn of 2008,the total phenotypic variation among the F2：3 lines accounted for by the QTLs for hypocotyl length and hypocotyl thick were 52.8% and 27.7%,respectively.In the spring of 2009,7 QTLs were identified,the total phenotypic variation were 34.6% and 34.7%,respectively.