基于掖478导入系的玉米雄穗分枝数QTL定位

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(P0.05)。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。

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

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.