【作者】 李华；

【导师】 刘曙东；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2013， 硕士

【摘要】 小麦作为人类一种主要的粮食作物，受到锈病、赤霉病以及白粉病等多种病害的挑战。小麦白粉病严重影响小麦产量和品质。人们通常使用化学方法防治白粉病，但化学药剂毒性较大，且大量长期使用会造成环境污染以及破坏，所以培育抗病品种为最安全有效的方法。抗源材料0911-3以及WP6192都是普通小麦中13与波兰小麦的杂交后代。基于对小麦抗源材料WP6192常规遗传规律分析基础上，结合分离群体分组分析法（BSA）和AFLP分子标记技术对抗源材料WP6192携带的抗白粉病基因进行精细定位。为了解小麦抗源材料0911-3以0911-3为母本与极度感病品系1130-2杂交，产生P1、P₂、F₁、BC₁、BC₂和F₂共6个家系世代，分别以倒二叶病害严重度（MDS）和病程曲线下叶面积（AUDPC）为成株抗性指标，应用主基因＋多基因混合遗传模型多世代联合分析方法进行遗传分析。主要研究结果如下：1.0911-3对白粉病的两种成株抗性指标的遗传基础基本是一致的，都符合2对加性-显性-上位性主基因＋加性-显性-上位性多基因遗传模型。其中，两对主基因的负向加性作用可以增强抗病性，感病基因具有部分显性作用；两对主基因间还存在各种相互作用，可以增强抗病性；分离世代以F2主基因＋多基因遗传率是最高的，F2的MDS和AUDPC的遗传率分别为91.87%和92.22%。2. WP6192为母本；感病小偃166为父本；组合杂交，2012年5月对P₁、P₂、F₁、F₂、BC1、BC2以及F2：3家系进行了小麦白粉病成株抗性鉴定，结果表明：F₁代21株表现为高抗；回交群体WP6192/小偃166//WP6192BC1149株全部表现为抗病；回交群体WP6192/小偃166//小偃166BC2中抗病植株61株，感病植株60株，抗感分离比值为1:1。由此可见，WP6192的抗病基因属于显性。F2群体中抗病植株240株，感病植株84株，抗感分离比值为3:1，通过对F2:3家系所有植株进行小麦白粉病苗期抗性鉴定，可以对F2抗病群体进行纯合抗病和杂合抗病的区分，结果为纯合抗病植株为75株；杂合抗病植株为149株；纯合子感病植株为84株。此外，纯合抗病：杂合抗病：纯合感病=1:2:1。结果表明抗源材料WP6192携带小麦抗白粉病基因为一对显性基因，本研究将其暂定名Pmwp6192。3.利用AFLP分子标记技术精细定位小麦抗白粉病基因Pmwp6192。以小麦抗源材料WP6192和小偃166杂交的F2群体作为分析群体，利用分离群体分组分析法（BSA法）对1280对组合的AFLP引物进行筛选，具有多态性的引物共有10对组合。对这些具有多态性的引物组合进行F2小群体（46株）检验，结果只有4对引物组合在小群体中具有多态性，分别为： X_P-AGA/M-GAC、X_P-GGA/M-GAC、X_P-CCA/M-GTA、X_P-TGA/E-ACA。4.利用F2大群体（303株）对稳定的多态性引物X_P-AGA/M-GAC、X_P-GGA/M-GAC、X_P-CCA/M-GTA、X_P-TGA/E-ACA进行验证其与抗病基因的关系。然后计算遗传距离，发现与小麦抗白粉病基因Pmwp6192连锁的2个AFLP标记为X_P-CCA/M-GTA和X_P-TGA/E-ACA。AFLP标记XP-CCA/M-GTA和XP-TGA/E-ACA分别位于小麦抗白粉病基因Pmwp6192的两侧，遗传距离分别为0.9cM和4.7cM，为该基因的分子标记辅助选择奠定了基础。更多还原

【Abstract】 Wheat is major grain crop for people, which is suffering the challenge of rust diseasegibberellic disease and powdery mildew and other various diseases. Powdery mildew hasheavy harm on wheat production, affects yield and quality of wheat. We could use chemicalsprevent wheat from powdery mildew, but chemicals is higher poisonous, it can causeenvironment pollution to use vast chemicals long time. So breeding wheat resistance speciesis the most safe and effective method. The resistant material0911-3and WP6192of this studyare F8stable plant breeding from the cross offsprings of Triticum polonicum L.×Zhong13.For fine mapping gene resistance to powdery mildew in resistant material WP6192, we cancombine BSA and AFLP molecular marker technique based on analyzing conventionalgenetic law.In order to realize the inheritance law of powdery mildew resistance in wheat0911-3, six populations （P1、P2、 F1、BC1、 BC2and F2） were from cross of0911-3×1130-2were used for studying the inheritance of resistance to powdery mildew by the mixed majorgene+polygene inheritant model with multiple generations analysising method with usingmaximum disease severity and leaf area under disease progress curve as adult plant resistanceindex. The results were:1. The inheritance of powdery mildew resistance of wheat0911-3of two adult plantresistance index was consistent, both were two pairs additive-dominant-epitasis major genes+additive-dominant-epitasis polygene model （E model）; Two major genes was negativeadditive effects, which can enhance resistance;There were variety of effects between twomajor genes, which can enhance resistance; The major gene plus poly-genes heritability of theF2was the highest in segregative generation, the heritability of MDS and AUDPC were91.87%and92.22%.2. WP6192was female parent, Xiaoyan166was male parent, cross group. Throughidentifying resistance to wheat powdery mildew of P₁、P₂、F₁、F₂、BC₁、BC₂and F2:3family after artificial inoculation in the field May,2012. The results showed:21plants werehigh resistant to powdery mildew in F₁; all149plants of backcross group WP6192/Xiaoyan166//WP6192BC1were resistant to powdery mildew; the number of resistance was61andthe number of susceptibility was60in backcross group WP6192/Xiaoyan166//Xiaoyan166BC2,the ratio of resistance and susceptibility was1:1. This showed the resistance of WP6192was dominant.240was number of resistance and the number of susceptibility was84in F2, the ratio of resistance and susceptibility was3:1. Through identifying resistance to powderymildew of F2:3family plants in the seeding, we can distinguish homozygous resistant withheterozygous, the results was the number of homozygous was70，during resistant plants，the number of homozygous was149，the number if susceptible plants was84. In addition theratio was1:2:1in F2:3family. So, the resistant gene to wheat powdery mildew of WP6192was a dominant gene, which was named Pmwp6192temporarily.3. Using AFLP molecular marker technique to fine mapping Pmwp6192. The analyzingpopulation was F₂population from the cross of WP6192and Xiaoyan166.Using bulkedsegregation analysis （BSA） method to screen1280pairs of AFLP markers, we get4pairsAFLP markers with polymorphism. Identifying this markers with polymorphism using F2small population （46plants）, only four pairs marker with polymorphism in F2smallpopulation, this were: X_P-AGA/M-GAC、X_P-GGA/M-GAC、X_P-CCA/M-GTA、X_P-TGA/E-ACA.4. XP-AGA/M-GAC、 XP-GGA/M-GAC、 XP-CCA/M-GTA、 XP-TGA/E-ACAmarkers with stablepolymorphism gene amplificat in F2large population （303plants） for studying the relationshipbetween markers and resistant gene. Using software Mapmaker/Exp V3.0to calculate andanalysis the genetic distance between markers and resistant gene, the results showed two pairsAFLP markers X_P-CCA/M-GTAand X_P-TGA/E-ACAwere linked to wheat resistant gene PmWP6192.These two AFLP markers, X_P-CCA/M-GTAand X_P-TGA/E-ACAlocated in P_mwp6192two sides, thegenetic distance was0.9cM and4.7cM respectively, which laid a foundation for the gene ofmolecular marker assisted selection.更多还原