【作者】 刘志勇； 宋伟； 华为； 赵军； 解超杰； 孙其信； 杨作民；

【Author】 Liu Zhiyong Song Wei Hua Wei Zhao Jun XieChaojie Sun Qixin Yang Zuomin Department of Plant Genetics & Breeding, China Agricultural University, Beijing, 100094

【机构】 中国农业大学植物遗传育种系；

【摘要】 野生亲缘物种是作物遗传改良的重要种质资源,对提高作物产量、改善品质、提高对生物和非生物逆境的抗性具有重要作用。小麦白粉病是世界范围内小麦重要病害之一,培育抗病品种是最为经济、有效和有利于环保的防治病害的手段。发掘新的抗白粉病基因,是培育抗病品种,实现抗性持久化的重要途径。野生二粒小麦(2n=4x=28;genome AABB)是栽培四倍体和六倍体小麦的野生祖先种, 具有高蛋白质含量、对逆境和病虫害抗性突出等特点,是普通小麦遗传改良的重要基因资源。利用抗病分离群体,我们在野生二粒小麦2B染色体上发现了多个抗白粉病基因,并利用SSR分子标记进行了定位。在2BS短臂上,发现了一个不完全显性抗病基因PmWE20和隐性抗病基因PmWE12;在2BL, 长臂上发现了一个显性抗白粉病基因PmWE35,这些新基因的发掘和紧密连锁SSR分子标记的建立, 为小麦抗白粉病基因分子标记辅助选择和基因积聚奠定了基础。此外,还在抗白粉病基因PmWE20附近,定位了小麦叶片蜡质基因的上位性抑制基因IW1。进一步利用EST-SSR,EST-SNP,AFLP等分子标记技术的精细遗传定位工作正在开展中。与水稻第4染色体的比较基因组分析表明小麦2BS染色体区域与水稻4S染色体区域具有良好的共线性,可以作为小麦基因精细遗传定位和基因克隆的强有力工具。更多还原

【Abstract】 Wild relatives of cultivated crop are important germplasm for improving yield, quality, resistance to biotic and abiotic stresses of modern cultivars. Powdery mildew, caused by Blumeria graminis f. sp. tritici, is one of the most important fungal disease of wheat (Triticum aestivum L.) worldwide. Breeding for resistance to powdery mildew is the most economical and effective way for controlling the disease. The wild emmer wheat, Triticum dicoccoides (2n=4x=28; genome AABB), is considered the progenitor of cultivated tetraploid and hexaploid wheats. Wild emmer wheat was found to be highly protein content, polymorphic for glutenin, tolerence to stress and resistance to several pathogens, including stripe rust, powdery mildew, leaf rust, and stem rust, as well as highly yield potential for wheat improvement. Several powdery mildew resistance genes derived from wild emmer accessions have been mapped on the short and long arms of chromosome 2B by SSR marker. Linkage maps of a dominant resistance gene PmWE20 (2BS) and a recessive resistance gene PmWE12 (2BS) have been constructed. Another dominant resistance gene PmWE35 has been mapped on chromosome arm 2BL. An epistatis inhibitor of glaucouness, a trait to be considered related drought tolerance, IW1 was also mapped on 2BS and 20cM away from PmWE20. EST-SSR, EST-SNP, AFLP and RGA markers are being employed to map more tightly linked DNA markers. Comparative analysis with rice indicated very good macrosynteny between rice chromosome 4S and wheat 2BS, which provinging. The tightly linked DNA markers will be used to screen an AABB genome BAC library and chromosome walking toward the resistance gene will be applied to construct a BAC DNA contig spaning the target gene with the help of comparative genome analysis between wheat and rice and barley. The BAC clones spanning the target gene will be sequenced to find the candidate powdery mildew resistance gene.更多还原