【作者】 马强；

【导师】 任正隆；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2006， 硕士

【摘要】 小麦白粉病是由小麦白粉菌（Erysiphe graminis f.sp.tritici）引起的气传真菌病害，它是影响世界各国小麦生产的重要病害之一。近年来，白粉病在我国小麦栽培中有逐渐加重的趋势，已成为威胁我国小麦生产安全的主要病害，对我国粮食安全构成了巨大的威胁。实践证明，筛选和培育抗病品种是防治小麦白粉病最经济有效而又安全的手段。小麦野生近缘种属蕴藏着丰富的抗性资源，是小麦白粉病抗性基因的重要来源。中间偃麦草是普通小麦的一个野生近缘物种，是多种小麦病害的良好抗源，其E染色体组上携带有白粉病抗性基因，对小麦白粉病表现免疫。 本实验室用小麦栽培品种川麦107与八倍体小偃麦TAI7047（太原768/中间偃麦草//76（64）杂交），从中选育出一些对小麦白粉病免疫的高代稳定品系。本文对其中的优良品系YU25的白粉病抗性进行了遗传学分析，并利用小麦微卫星标记对其抗性基因进行了染色体定位。获得的主要结果如下： 采用常规遗传分析方法，以感白粉病小麦品种MY11与YU25杂交和回交的后代F₁、F₂、BC₁F₁、BC₂F₁和MY11、YU25以及YU25的系谱亲本亲本CM107、TAI7047、Taiyuan768、76（64）和中间偃麦草等等为材料，采用四川省当前流行的小麦白粉病优势生理小种人工接种进行白粉病抗性接种鉴定，对YU25的白粉病抗性进行了遗传分析。结果表明，YU25含有2对表现免疫反应和高抗反应的显性抗病基因，它们均来源于中间偃麦草，暂命名为PmE（免疫）和PmYU25（高抗）。 使用分离群体分组分析法（BSA），用294对小麦微卫星引物和221个F₂植株，对这2个基因进行连锁分析，结果发现小麦微卫星标记Xgwm-297-7B与PmE基因的遗传距离为13.0cM，而Xgwm-210-2D与PmYU25基因的遗传距离为16.6cM，因此将PmE和PmYU25分别定位在7BS和2DL上。 迄今为止，在已定名的抗小麦白粉病基因中，尚未见到有来自中间偃麦草的报道，也没有见到在小麦染色体2DL和7BS上有白粉抗性基因的相关文献。因而，根据系谱和基因位点分析，推断PmE和PmYU25均为起源于中间偃麦草、不同于已知的抗小麦白粉病基因的2个新基因。更多还原

【Abstract】 Powdery mildew caused by Erysiphe graminis （DC） E. O. Speer f. sp. tritici E’m. Marchal, is one of the most important wheat （Triticum aestivum L. em Thell） diseases in many regions of the world. In recent years, the powdery mildew harms has become worse and worse in china wheat cultivation, and it has become one of major desease that threaten china wheat produce and food safety. The use of resistant cultivars is the most economical, efficient and environmentally safe way to control powdery mildew. Wild relatives of wheat have a large of resistance resources, and are a rich gene source for powdery mildew resistance. Elytrigia intermedium is one wild relatives of wheat, it is a good resistance resource to wheat diseases, and itsE group chromosome have immune resistance gene to powdery mildew. A new wheat line YU25, which derived from a wide cross between a wheat cultivarCM107 and octoploid Trititrigia TAI7047 （Taiyuan768/ Elytrigia intermedium//76（64））, exhibit immune to wheat powdery mildew. Genetic analysis of its resistance to powdery mildew and linkage analysis of its resistance genes were be researched in the present study. The main results are summaried as follows:By common analysis methods of classical genetic, the line YU25 was crossed with a susceptive wheat cultivar Mianyang 11 （MY11） and backcrossed both with MY11 and YU25 to produce their F₁, F₂, BC₁F₁, BC₂F₁ populations and MY11, YU25, CM107, TAI7047, Taiyuan768,76（64）, Elytrigia intermedium, which were grown in greenhouse and inoculated by the epidemic predominant race of powdery mildew in Southwest China. The response patterns of F₂ population showed that the I （immune） : R （resistant） : S （susceptible） segregation ratio closely fit to 12 : 3 : 1, suggesting that the wheat line YU25 carried two different dominant resistance genes to powdery mildew, one of them exhibited immune and the other showed highly resistant. The results was also supported by the 2 :1 :1 separation ratio of I: R : S in the BC₁F₁ population. Another result shows that the two genes have originated更多还原