玉米果穗出子率QTL定位及上位性分析

QTL mapping and epistasis analysis for rate of kernel production in maize

利用郑58×昌7-2组配的225个F2单株为作图群体,构建了全长为1 987.7 cM、覆盖玉米基因组10条染色体的分子标记遗传连锁图,标记间平均距离11.0 cM.采用复合区间作图方法(C IM),对玉米出子率性状进行QTL定位,利用多区间作图法(M IM)对上位性效应进行了分析.结果表明,在玉米第1染色体和第3染色体上检测到2个稳定的QTL位点,分别可以解释8.47%和10.52%的表型遗传变异.检测到5对上位性QTL,涉及6个位点,分布于第1,2,3,4和第5染色体,共解释9.94%表型遗传变异.这说明除了加性效应和显性效应外,上位性效应也是出子率性状的重要遗传基础.

Two hundred and twenty-five F2 individuals derived from the single cross of inbred lines Zheng 58 and Chang 7-2 were used for map construction,the markers in the linkage map distributed on all the 10 maize chromosomes and covered 1 987.7 cM,with average distance of 11.0 cM between markers.In year 2007 and 2008,a F2：3 population along with the parents Chang 7-2 and Zheng 58 were planted in Jiyuan,Henan.QTL mapping for maize rate of kernel production（RKP） were firstly analyzed by composite interval mapping（CIM） method.Two common QTL were identified and distributed on chromosomes 1 and 3,and can explain 8.47%~10.52% of observed phenotypic variation.The interactions among detected QTL were identified using multiple interval mapping（MIM） method based on the results of CIM analysis.Five pairs of epistatic interactions were detected,involving 8 loci distributed on chromosomes 1,2,3,4 and 5,respectively,which totally contributed 9.94% of the phenotypic variation.The results showed that besides the additive and dominance effects,epistasis interactions also play an important role in production rate of kernel of maize.