基于掖478导入系的玉米雄穗分枝数QTL定位

QTL Mapping of Tassel Branch Number of Maize Derived from Introgression line with Genetic Background of Ye478

为玉米雄穗分枝数的遗传改良和分子育种提供参考,以有掖478遗传背景的SL19-22导入系为母本与轮回亲本掖478杂交,构建F2群体,在3种生态环境下田间种植观察亲本及其F2群体的雄穗分枝数,并采用SSR标记和单标记作图法进行基因型鉴定和雄穗分枝数的QTL定位分析。结果表明:2016年在QY、SH和SF环境下,掖478亲本的雄穗分枝数分别为(17.5±2.5)个、(14.8±2.1)个和(19.0±2.4)个,SL19-22亲本分别为(10.2±2.4)个、(11.3±1.7)个和(12.9±1.7)个,F2群体分别为(12.9±2.7)个、(13.9±4.2)个和(14.5±3.8)个,且2亲本的雄穗分枝数差异达显著水平(P<0.05)。在SH和SF环境下,检测到在第5染色体umc1225位点处有1个控制雄穗分枝数的QTL位点,其对雄穗分枝数表型变异的贡献率分别为24.4%和33.9%。因此,雄穗分枝数较少的SL19-22亲本可作为种质材料进行雄穗分枝数改良,umc1225则可用于玉米雄穗分枝数的分子标记辅助选择育种。

The tassel branch number（TBN）of F2 population between SL19-22 introgression line×Ye478,SL19-22 and Ye478 was observed under three ecological environments and the genotype identification and QTL mapping of TBN are analyzed by SSR marker and single marker mapping to provide a reference for genetic improvement and molecular breeding of TBN in maize.Results：The TBN of Ye478 under QY,SH and SF environment is（17.5±2.5）,（14.8±2.1）and（19.0±2.4）in 2016 respectively.The TBN of SL19-22 under QY,SH and SF environment is（10.2±2.4）,（11.3±1.7）and（12.9±1.7）and the TBN of F2 population under QY,SH and SF environment is（12.9±2.7）,（13.9±4.2）and（14.5±3.8）separately.There is a significant difference in TBN between Ye478 and SL19-22.One QTL mapping to control TBN is detected on umc1225 locus of the fifth chromosome under SH and SF environment and the contribution rate to TBN phenotypic variation is 24.4%and 33.9% under SH and SF environment respectively.In conclusion,SL19-22 with less TBN can be used as a germplasm material for improvement of TBN and umc1225 can be used for molecular marker-assisted selection breeding of TBN in maize.