中文摘要：

目的基因精细遗传连锁图谱的构建是图位克隆的基础,小麦功能基因精细遗传连锁图谱的构建依赖于比较基因组学分析。水稻和短柄草（Brachypodium distachyon）基因组序列是小麦比较基因组学分析和功能基因精细遗传定位的重要工具。本研究利用小麦、短柄草和水稻的基因组共线性关系对小麦抗白粉病基因pm42进行比较基因组学分析,明确了pm42基因所在2BS基因组区域与短柄草第1染色体和水稻第3染色体直系同源基因组区域的对应关系,开发出与抗白粉病基因pm42连锁的EST-SSCP（expressed sequence tag-single strand conformation polymorphism）标记CD452782和BF201235,以及EST-STS（expressed sequence tag-sequence tagged site）标记CJ674042、EB513371和CV771633,构建了pm42基因EST标记遗传连锁图谱,CJ674042、BF201235、CD452782和CV771633位于pm42近端粒侧,距离pm42的遗传距离分别为1.9、12.0、19.7和25.7cM;EB513371位于pm42近着丝粒侧,与pm42的遗传距离为14.6cM。整合原有的作图数据,构建了pm42基因的高密度比较基因组学遗传连锁图谱,pm42被定位于3.3cM的区间,该区间对应于短柄草66kb的基因组区域及水稻69kb的基因组区域。该结果为抗白粉病基因pm42高密度精细遗传连锁图谱构建、分子辅助选择和基因聚合奠定了基础。

英文摘要：

Constructing fine genetic linkage map of target gene provides a starting point for map-based cloning.Fine genetic mapping of functional genes in wheat has benefited greatly from comparative genomics analysis.The genome sequences of rice and Brachypodium distachyon provide powerful tools for comparative genomics analysis and fine genetic mapping of target gene in wheat.In the present study,comparative genomics analysis using wheat-Brachypodium-rice genomic colinearity showed that genomic region containing pm42 in wheat 2BS was orthologous to Brachypodium chromosome 1 and rice chromosome 3.Two EST-SSCP markers,CD452782 and BF201235,three EST-STS markers,CJ674042,EB513371,and CV771633,linked to pm42 were developed and an EST marker-based genetic linkage map of pm42 was constructed.CJ674042,BF201235,CD452782,and CV771633 were distal to pm42 with genetic distances of 1.9,12.0,19.7,and 25.7 cM,respectively.EB513371 was proximal to pm42 with a genetic distance of 14.6 cM.An integrated high-density comparative genomics genetic linkage map of pm42 was constructed and the powdery mildew resistance gene was mapped in a 3.3 cM interval orthologous to 66 kb and 69 kb genomic regions in Brachypodium chromosome 1 and rice chromosome 3,respectively,providing useful information for the fine mapping,molecular assisted selection and gene pyramiding of pm42.