基于元分析的抗玉米灰斑病QTL比较定位

以玉米遗传连锁图谱IBM2 2008 Neighbors为参考图谱,整合65个抗玉米灰斑病QTL,构建QTL综合图谱。采用元分析方法优化65个QTL,获得11个"一致性"QTL区间,分别位于染色体bin区的1.05、1.06、2.03、2.07、3.02、4.05、5.03、5.05、7.02、8.07、9.03位置,其在遗传连锁图谱上对应的位置分别为442.21、528.27、228.10、478.00、74.65、311.59、169.62、302.35、252.19、422.70、257.93 cM。对两个具有较多报道和较高表型贡献的"一致性"QTL区间bin1.05和bin1.06,从MaizeGDB网站搜索得到324个基因。因抗病基因在结构上具有高度保守性,将324个基因分别与水稻和拟南芥基因组进行同源比对,在bin1.05和bin1.06内分别确定了7个和3个基因作为玉米抗灰斑病候选基因。

Comparative QTL Mapping of Resistance to Gray Leaf Spot in Maize Based on Meta-analysis of QTL Locations

An integrated quantitative trait locus(QTL) map for maize gray leaf spot(GLS) resistance was con-structed by projecting a total of 65 available QTLs based on IBM2 2008 neighbors. Eleven consensus QTLs were identified using meta-analysis approach. These QTLs were found on chromosome bins 1.05, 1.06, 2.03, 2.07, 3.02, 4.05, 5.03, 5.05, 7.02, 8.07, and 9.03, and the corresponding position on genetic map were 442.21, 528.27, 228.10, 478.00, 74.65, 311.59, 169.62, 302.35, 205.05, 422.70, 257.93 cM. Consensus QTL regions located on chromosome 1.05 and 1.06 with more reports and phenotypic contributions were selected to search for genes on MaizeGDB website, and 324 genes were found. Since most resistance proteins contain conserved motifs, three hundred and twenty-four genes were projected onto Oryza sativa and Arabidopsis thaliana genome on the website of Phytozome. As a result, seven and three genes were selected to be as candidate genes resistance to maize gray leaf spot.