【目的】鉴定玉米籽粒灌浆过程中控制容重动态变化的QTL,为容重相关关键基因的克隆奠定基础。【方法】利用一套来源于玉米杂交种农大108(许178×黄C)的包含166个家系的RIL群体,于2009年和2010年分别在郑州、安阳按随机区组设计进行种植。开花时选择生育期一致的植株挂牌,并在授粉后15、22、29、36、43和50 d分期收获,风干穗样籽粒,测定重组近交系群体灌浆不同时期籽粒的容重变化,容重相关数据的统计分析用SPSS18.0软件进行。利用覆盖全基因组的822对SSR标记获得亲本间的多态性标记信息,选择216对在亲本和群体中带型都很清晰的多态性SSR标记构建遗传连锁图谱。以构建的遗传连锁图谱为基础,利用Win QTLCart 2.5复合区间作图在0.05显著水平进行1 000次模拟,检测控制容重动态变化相关的QTL。【结果】农大108及其亲本容重随籽粒灌浆进程的推进不断增加,且呈现慢-快-慢的趋势。遗传因素是影响容重的主要因素,环境因素对容重的影响在籽粒灌浆高峰期较前期和后期小。不同年份间,容重在灌浆DAP22至DAP43期间表现出显著的差异,但最终的容重在年份间差异较小。在籽粒灌浆不同时期,农大108的容重表现多介于双亲之间,没有出现超亲优势情况,表现典型的加性效应。对RIL群体容重性状进行t测验,在不同年份间籽粒灌浆过程中均存在显著差异。4个环境条件下,6个籽粒发育时期,共检测到31个容重相关的QTL,分布在玉米第1、2、3、5、6、7、8和9染色体上,分别有2、4、5、3、4、5、3和3个QTL。这些QTL中,13个QTL的加性效应来自亲本黄C(正值),18个QTL的加性效应来自亲本许178(负值)。单个QTL对容重表型的贡献率在5.9%—29.7%。q TW2c在2010年安阳试点DAP22和DAP36被检测到,贡献率分别为11.5%和14.7%;q TW3c在2009年郑州试点DAP29和DAP36被检测到,贡献率分别为22.2%和14.7%。【结论】q
【Objective】Identifying the QTLs controlling test weight dynamic change during maize grain filling will benefit for gene cloning of the related key QTLs. 【Method】In 2009 and 2010, a set of RIL population with 166 inbred lines derived from hybrid Nongda108(Xu178 crossed with Huang C) was planted in Zhengzhou and Anyang with randomized block design. The ear samples of recombinant inbred lines with the same silking date were hand-harvested performed by time-course harvesting on 15, 22, 29, 36, 43, and 50 days after pollination for test weight evaluation. Phenotypic analysis was performed using SPSS18.0 software. The 822 pairs of SSR covering the whole maize genome were used to detect the polymorphisms between the two parents. And, 216 SSR markers were selected for linkage map construction. With the linkage map, QTLs responsible for test weight were evaluated by composite interval mapping program in the Win Cart QTL 2.5 software. 【Result】Test weight of Nongda108 and its two parents tended to be a slow-fast-slow pattern along with the grain filling process. Genetic factor showed predominant factor on test weight, while environmental factors mainly did their effects during the early and the late stages rather than the peak stage. Between two years, the test weight of DAP22-DAP43 showed a significant difference, but no significant difference at the last stage. The test weight of hybrid Nongda108 was among the two parents exhibiting typical additive effects within different developmental periods. Via time-related QTL analysis, 31 QTLs were detected for test weight of six sampling stages under four environments. These QTLs were located on all the 10 chromosomes of maize genome with exception of chromosomes 4 and 10. And, the 2, 4, 5, 3, 4, 5, 3, and 3 QTLs were distributed on chromosomes 1, 2, 3, 5, 6, 7, 8 and 9, respectively. Among them, additive effect of 13 QTLs was contributed by Huang C(+), while additive effect of another 18 QTLs was contributed by Xu178(-). The contribution of single QTL v