【作者】 王秀波；

【导师】 韩德俊；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2012， 硕士

【摘要】 小麦条锈病是由条锈菌（Puccinia striiformis f.sp tritici）引起的一种气传性真菌病害，遍及世界各主要麦区。在我国，小麦条锈病曾多次发生大流行，给小麦生产造成了重大损失，已成为影响小麦生产可持续发展的主要限制因素。选育和种植抗病品种是防治条锈病最经济，有效和生态安全的方法。由于我国多数生产品种具有相同的抗性基因或抗谱相近，造成遗传基础狭窄、单一，近年来，随着CYR32等流行小种的产生，我国小麦主产区的生产品种大多丧失了抗锈性。因此，发掘新的抗源和抗条锈病基因，尽快选育新的抗锈品种，拓宽小麦抗条锈病基因的遗传基础，增加其遗传多样性，为我国小麦抗病遗传改良提供丰富的抗源材料，对于防治小麦条锈病害具有重要的意义。小麦的许多野生近缘物种都含有丰富的抗性基因，利用远缘杂交将外源遗传物质导入小麦是创制抗病小麦新抗源材料的有效途径。一粒小麦(Triticum monococcum)与葡萄牙野燕麦(Avena fatua L.)经过杂交，得到了杂种后代一粒葡(YLP)系列。本研究通过细胞学，条锈病鉴定和筛选，得到了对我国目前小麦条锈菌流行小种均表现抗病的选系，并对其进行了遗传分析和分子标记。主要取得了以下结果。1．在一粒小麦与葡萄牙野燕麦远缘杂交后代中选育了5个形态学稳定的抗条锈病衍生系YLP-1、YLP-7、YLP-9、YLP-13和YLP-16，对该衍生系的细胞遗传学特征进行了鉴定：根尖体细胞染色体数目均为2n=42，花粉母细胞减数分裂中期Ⅰ染色体构型均为2n=21Ⅱ，与中国春杂种F1花粉母细胞减数分裂中期Ⅰ染色体构型存在着二价体、游离的单价体、多价体以及落后染色体，异常构型率为16%～50%。细胞遗传学初步鉴定表明了这5个衍生系均为易位系，验证了一粒葡是远缘杂交的后代。2．从一粒葡后代中选出了9个株系用9个条锈菌小种进行苗期抗病性鉴定，分析表明有5个株系YLP-1-4、YLP-7、YLP-9-1、YLP-9-3、YLP-16-1对所有参试小种都表现为高抗，且与已知的Yr24/Yr26基因不同，说明一粒葡是一个优良的抗条锈病抗源材料。用目前国内毒性最强的流行小种CYR32对YLP-1-4和YLP-7进行了苗期抗条锈性遗传分析，结果表明，YLP-1-4对CYR32的抗病性由一对显性核基因控制；YLP-7对CYR32的抗病性由1对显性和1对隐性核基因控制。3.利用分离群体分析（BSA）法对SSR引物进行筛选，获得了7个与YLP-7中显性抗条锈病基因YrYLP连锁的多态性标记，他们分别是Xwmc419、Xbarc187、Xwmc269、Xbarc137、Xwmc216、Xwmc694和Xbarc181，遗传距离分别为10.2、5.4、3.6、2.4、3.6、4.8、8.4。故YrYLP位于1B染色体的着丝点附近。其中Xbarc137和Xwmc216两个标记分布在YrYLP的两侧，与其连锁距离分别为2.4cM和3.6cM。这些紧密连锁的SSR标记可用于小麦抗条锈病分子标记辅助育种。已知定位于小麦1B染色体的抗条锈病基因抗病性检测及分子标记检测结果表明，YrYLP很可能是一个不同于这些已知基因的新基因，一粒葡作为条锈病的优良抗源材料在抗病育种中将具有重要的利用价值。更多还原

【Abstract】 Wheat stripe rust, caused by Puccinia striiformis f.sp tritici, is an airborne fungaldisease occurred many times pandemic in China, affecting wheat production for sustainabledevelopment limiting factor. Breeding and planting resistant varieties is the most economic,efficient and environmentally friendly methods to prevent wheat rust. The wheat geneticbasis of our country is scarce because most varieties have the same or similar resistancegenes. In recent years, with epidemic of strains CYR32et al, the main cultivars ofwheat-growing areas in China lost their resistance to stripe rust. Therefore, it must be ofgreat significance to lasting controlling strip rust to explore and create new resistancematerials and genes, to breed new rust-resistant varieties, to increase diversity of resistancegenes and provide rich material reserve for genetic transformation of wheat diseaseresistance.The wild relative species of wheat has a wealth of genetic diversity as many containabundant resistance genes of stripe rust. Using artificial distant hybridization to introduceexogenous genetic material into wheat is an effective way to create new wheat antigenicmaterials. We obtained hybridization descent series named YLP after Triticum monococcumand Avena fatua for hybridization.By using identification and screening of cytology and striperust, the paper obtained resistant lines to epidemic strains of Puccinia striiformis f.sp tritici inour country, and its genetic analysis and molecular markers were done. Achieved results areas follows:1. Five lines of YLP, YLP-1、YLP-7、YLP-9、YLP-13and YLP-16, the distanthybridization generations between Triticum monococcum and Avena fatua L., which stabilityresistant to Puccinia striiformisf. sp. tritici.(Pst) were selected as experiment materials.Cytogenetic analysis and resistance evaluation of these hybrid derivatives were done.2n=42chromosomes were observed after identification root tip in cytology and the chromosomeconfiguration of most Pollen mother cell during metaphaselofmeiosis Ⅰ were2n=21Ⅱ;Meanwhile In the pollen mother cell of F1drivided from five derivatives andChinese Spring, There were0.84univalents and20.60pairs of bivalents could be observed in average cell. The frequency of abnormal cells were16%～50%. Some multivalentchromosomes and Lagging chromosomes were found in YLP-1、YLP-13、YLP-16whichindicated these materials were translocation lines. YLP were verified generations from distanthybridization.2. Nine lines were selected from hybridization generations between Triticummonococcum and Avena fatua L. for seedling resistance identification, used nine Pucciniastriiformisf. sp. Tritici strains, analysis showed that five lines, YLP-1-4, YLP-7, YLP-9-1,YLP-9-3, YLP-16-1, performed highly resistant to each strain selected, and they weredifferent from gene Yr24/Yr26, therefore, YLP was proved to be a good antigen material toPuccinia striiformisf. sp. Tritici. Genetic analysis of YLP-1-4and YLP-7of resistance tostripe rust, using CRY32, the most toxic epidemic strain in China, showed that the resistanceof YLP-1-4was controlled by a pair of dominant nuclear genes, against YLP-7controlled bya pair of dominant genes and a pair of recessive nuclear genes.3. SSR primers were screened by using bulk segregant analysis (BSA) method, sevenpolymorphic markers linked with dominant stripe rust resistance gene were gotten in YLP-7,Xwmc419, Xbarc187, Xwmc269, Xbarc137, Xwmc216, Xwmc694, Xbarc181respectively,the genetic distances10.2,5.4,3.6,2.4,3.6,4.8,8.4respectively, the location of gene YrYLPwas predicted in chromosome1B near the centromere. The markers Xbarc137and Xwmc216distributed on both sides of YrYLP, and genetic distances2.4cM and3.6cM. These closelylinked SSR markers can be applied to molecular marker-assisted breeding. Test results ofresistance testing and molecular markers of stripe rust resistance genes known located onwheat chromosome1B showed that YrYLP is likely to be a new gene different from theseknown genes. As an excellent stripe rust resistance source material, YLP will have importantvalues in wheat breeding for disease resistance.更多还原