基于元分析的抗玉米丝黑穗病QTL比较定位

以玉米遗传连锁图谱IBM2 2005 Neighbors为参考图谱,通过映射整合不同试验中的抗玉米丝黑穗病QTL,构建QTL综合图谱。在国内外种质中,共发现22个抗病QTL,分布在除第7染色体外的9条玉米染色体上。采用元分析技术,获得2个“一致性”抗病QTL,图距分别为8.79 cM和18.92cM。从MaizeGDB网站下载“一致性”QTL区间内基因和标记的原始序列;采用NCBI网站在线软件BLASTx通过同源比对在2个“一致性”QTL区间内初步获得4个抗病位置候选基因。借助比较基因电子定位策略,将69个水稻和玉米抗性基因定位于玉米IBM2图谱上,在2个“一致性”QTL区间内分别发现1个水稻抗性基因,初步推断为抗病位置候选基因。本文结果为抗玉米丝黑穗病QTL精细定位和分子育种提供了基础。

Comparative QTL Mapping of Resistance to Sporisorium reiliana in Maize Based on Meta-analysis of QTL Locations

The integration QTL map for Sporisorium reiliana resistance in maize was constructed by compiling a total of 22 QTL available for this trait with Genetic Map IBM2 2005 Neighbors as reference.These 22 QTL were found to be located on 9 chromosomes of maize with exception of chromosome 7.Using a meta-analysis method,2 "consensus" QTL were identified on chromosomes 2 and 3 with map interval of 8.79cM and 18.92cM,respectively.The gene and marker sequences within 2 "consensus" QTL were downloaded respectively from website Maize GDB,and 4 positional candidate genes were identified by comparing these sequences against resistance genes of other Poacease by internet software BLASTx.Using a synteny conservation approach based on comparative mapping between maize genetic map and rice physical map,a total of 69 rice and maize resistance genes were projected onto maize genetic map IBM2 2005 Neighbors,and one each rice resistance gene was found in 2 "consensus QTL".The results provided useful information for fine mapping!QTL,gene cloning and molecular breeding for resistance to Sporisorium reiliana in maize.