玉米株高和穗位高遗传基础的QTL剖析

利用玉米强优势组合(Mo17×黄早四)自交衍生的191个F2单株构建了由SSR和AFLP标记组成的分子连锁图谱.F2进一步自交产生的184个F2:3家系用于调查株高和穗位高的表型值.采用基于混合线性模型的复合区间作图法和相应的作图软件QTLmapper/V2.0,分别定位了7个株高和6个穗位高QTL;检测到18对控制株高和13对控制穗位高的上位性效应位点;同时发现了与环境存在显著互作的6个株高和8个穗位高单位点标记区域以及4对株高和4对穗位高上位性效应区域.分析了各种遗传因素在株高和穗位高遗传基础中的相对作用大小,指出了加性、显性和上位性是玉米株高和穗位高的重要遗传基础.并对所定位的QTL的真实性、株高和穗位高的关系以及研究结果对分子育种的启示予以讨论.

Study on the Genetic Basis of Plant Height and Ear Height in Maize(Zea mays L. )by QTL Dissection

One hundred and ninety-one F2 individuals derives from the cross, Mo17xHuangzao4, were genotyped by SSR and AFLP markers to construct the genetic linkage map, and 184 corresponding F2:3 families were phenotyped for maize (Zea mays L.) plant hright and ear height in Changping and Shunyi. A mixed linear model approach and its software were used to detect QTLs with main effect, QTLs involved in digenic interations and Q x E interations. In total, 7 QTLs of plant height, 18 pairs of digenic epistatic loci of plant height, 13 pairs of digenic epistatic loci of ear height were detected. It was found that 6 QTLs of plant height, 8 QTLs of ear height, and 4 pairs of digenic epistatic loci of plant height and ear height and a significant interaction with environments. Genetic compnents underlying these quantitative traits were analyzed, and the study showed that additive, dominance and epistaship between plant height and ear height, and the results described above were also discussed for their possible application in molecular breeding.