【目的】玉米穗行数与产量密切相关,剖析其遗传基础对指导玉米育种实践具有重要意义。【方法】以只有4行籽粒的中国特异地方品种四路糯选系和多穗行数的自交系农531为亲本,采取单粒传法(single seed descend method,SSD)构建正反交F_(2:3)分离群体。在北京昌平和河南新乡采用随机区组试验设计进行分离群体家系的穗行数表型鉴定。与此同时,根据玉米基因组数据库上公布的标记信息,在全基因组范围内筛选获得173个具有多态性的SSR标记,用于群体基因型鉴定及遗传图谱构建。采用完备区间作图法(ICIM)和复合区间作图法(CIM)进行玉米穗行数QTL定位和遗传效应分析,利用SAS软件GLM程序估计主效QTL对分离群体穗行数遗传变异的贡献率。【结果】表型鉴定结果表明,亲本四路糯选系与农531的穗行数平均值分别为4.0行与19.2行,F_(2:3)家系穗行数变化范围为4.0—17.4行。利用完备区间作图法,分别对北京昌平、河南新乡的正交F_(2:3)群体进行穗行数QTL定位,2个环境下共检测到12个穗行数QTL,分布于除第1、7染色体外的其他8条染色体上。等位变异来源分析表明,本研究定位的QTL减效等位变异全部来自少穗行数亲本四路糯选系。共有5个主效QTL在2个环境下均被检测到,其中,位于bin2.04区间内的主效位点qKRN2-1在单环境下最大可解释群体穗行数变异的18.48%,其余4个主效位点及其单环境下解释的最大表型变异分别为qKRN4-2(11.5 8%)、qKRN5-1(13.55%)、qKRN8-2(16.91%)和qKRN9-1(9.66%)。利用复合区间作图法,在联合环境条件下共检测到5个穗行数QTL,分布在第2、4、5、8、9染色体上,每个QTL解释的表型变异范围为6.13%-10.05%,除位于第5染色体的QTL以外,其余4个位点与完备区间作图法定位到的主效QTL区间一致。一般线性模型分析显示,在2个环境下,5个主效QTL可分别解释正交F_(2:3)群体51.5%(北京昌平)和54.0%(河南新乡)的表型变异。还定位到2对穗行数上位性QTL位点,分布于第2,、4、9染色体上,但表型贡献率分别仅为2.90%和1.80%。【结论】穗行数减效等位变异全部来自四路糯选系,鉴定出5个玉米穗行数主效QTL,分别位于bin2.04、bin4.09、bin5.04、bin8.05和bin9.03。表明该四路糯选系可作为重要的穗行数遗传研究材料,而定位到的主效QTL可作为玉米穗行数候选基因图位克隆和玉米遗传基础研究的重要候选区段。 【Objective】 The number of maize ear rows is closely related to the yield. It is of great significance to analyze the genetic basis of maize maize breeding. 【Method】 A single seed descend method (SSD) was used to construct the reciprocal cross of F4 (2: 3) to separate the population. In Beijing Changping and Xinxiang, Henan, randomized block design was used to identify the phenotypes of ear lines of segregating population. At the same time, 173 polymorphic SSR markers were screened from the whole genome based on the marker information published on the maize genome database for genotyping and genetic map construction. The QTL mapping of corn ear number and genetic effect were analyzed by complete interval mapping (ICIM) and composite interval mapping (CIM), and the contribution rate of major QTLs to the genetic variation of ear rows in the segregation population was estimated by SAS software GLM program . 【Result】 The results of phenotypic identification showed that the average number of ear rows of four lines and Nong 531 were 4.0 lines and 19.2 lines, respectively. The number of panicle lines of F 2: 3 lines ranged from 4.0-17.4 lines. QTL mapping was used to determine the number of ear rows in orthogonal F_ (2: 3) population in Changping of Beijing and Xinxiang of Henan, respectively. A total of 12 QTLs per panicle were detected in two environments, , 7 extrachromosomal 8 other chromosomes. Allelic variation of source analysis showed that all QTLs for QTL mapping in this study were derived from the four lines with fewer spike lines. A total of five major QTLs were detected in two environments. Among them, qKRN2-1, which is located in the locus of bin2.04, accounted for 18.48% of the variation of ear number in single population, and the remaining 4 The main phenotypic variation explained by the major loci and their single environments were qKRN4-2 (11.58%), qKRN5-1 (13.55%), qKRN8-2 (16.91%) and qKRN9-1 (9.66%), respectively. . Using composite interval mapping method, five QTLs for ear rows were detected under the combined environmental conditions, which were distributed on chromosomes 2, 4, 5, 8 and 9. The range of phenotypic variation explained by each QTL was 6.13% 10.05%. Except for the QTL located on chromosome 5, the other 4 loci were consistent with the main QTLs mapped by complete interval mapping. The general linear model analysis showed that the five major QTLs could explain the phenotypic variation of 51.5% (Changping) and 54.0% (Xinxiang, Henan) of the orthogonal F_ (2: 3) population under the two environments respectively. Two pairs of epistatic QTLs were also mapped on chromosomes 2, 4 and 9, but their phenotypic contribution rates were only 2.90% and 1.80%, respectively. 【Conclusion】 All of the allelic variation alleles of ear rows were all from the four-way waxy germplasm lines. Five major QTLs for ear rows were identified, which were located in bin2.04, bin4.09, bin5.04, bin8.05 and bin9 .03. The results showed that the four lines of waxy lines could be used as important genetic material for ear lines. The major QTLs mapped to the four lines could be used as important candidate segments for candidate gene mapping and maize genetic basis.