【作者】 丁俊强；

【导师】 吴建宇；

【作者基本信息】 河南农业大学 ， 作物遗传育种， 2003， 硕士

【摘要】 本研究通过对不同的玉米育种材料进行人工接种鉴定，筛选出一份优良的抗玉米矮花叶病自交系四一，并通过经典遗传学分析，结合微卫星分子标记，对四一的抗性进行了研究，对其抗病基因进行了定位，主要结论如下： 1．通过田间人工接种鉴定，从89份育种材料中筛选出4份高抗玉米矮花叶病材料和24份抗病材料以及28份中抗材料，其中筛选出的优良自交系四一在全生育期抗病。 2．对抗感组合四一×Mo17的P₁、P₂、F₁、F₂、BC₁、BC₂ 6个群体进行了抗性跟踪调查，并在调查基础上开展抗病性状的经典遗传学研究，结果表明：四一的成株期抗性由两个主基因控制，两个抗病基因表现为显性互补作用。 3．以四一×Mo17的F₂为作图群体，利用90对微卫星标记（亲本间有多态性）进行全基因组筛选，在第三和第六染色体的着丝点附近各发现了一个抗病基因位点，验证了表型遗传研究的推断；通过对242个F₂单株进行微卫星分析，对这两个抗病基因进行了定位，其中，第三染色体上的抗病基因距紧密连锁的双侧微卫星标记UMC1527和UMC2020的遗传距离分别约为1～2cM和5～6cM；第六染色体上的抗病基因距紧密连锁的双侧微卫星标记bnlg1600和phi075的遗传距离分别约为2～3cM和4～5cM；同时，61个BC₂单株的基因型检测结果，也验证了表型抗性遗传研究的推断。 4．在F₂单株基因型分析结果的基础上，结合不同时期的田间抗病性状调查，对这两个抗病基因的功能进行进一步的探讨，表明第六条染色体上的抗病基因与接种后早期抗病性有关。 目前，己鉴定出的抗玉米矮花叶病材料较少，只有少数几个抗病基 因被定位。玉米矮花叶病新抗源四一的发现和其抗病基因的定位，拓宽 了抗玉米矮花叶病基因资源，为抗玉米矮花叶病育种和抗病基因克隆、 分子标记辅助选择育种等工作的开展奠定了基础。更多还原

【Abstract】 Maize dwarf mosaic is one of the devastating and widespread viraldiseases caused by Maize Dwarf Mosaic Virus (MDMV) in the world .In recent years it has increased steadily in China and become more and more serious due to the infected cultivars. The most effective way to put the disease under control is to breed and popularize resistant hybrids, which based on resistant materials and understanding the resistance to MDMV. In this study, materials with different background were screened based on the resistance to MDMV. The inbred line SIYI with elite agronomy traits was singled out and its resistance to MDMV was studied. The results obtained were as following:1. Four highly resistant materials, 24 resistant materials and 28 moderately resistant materials to MDMV out of 89 maize germplasm were screened out after rub-inoculation. Tropical and subtropical germplasm in maize were found with the resistance genes by pedigree analysis. The inbred line SIYI is one of the resistant materials with elite agronomy traits.2. The resistance of SIYI was analysized by Mendel genetic model when crossed with susceptible inbred line Mo 17, when investigated at adult stage, 50 FI plants and 141 BCi plants were completely resistant to MDMV. The segregation of resistant and susceptible plants in SIYIxMo17 F2 plants and BC2 plants fitted into 9:7 and 1:3 ratio respectively, which showed SIYI carried two complementary dominant genes responsible for the resistance to MDMV at adult stage.3. Based on maize high-resolution molecular genetic map, SSR markers near the chromosome 3 and chromosome 6 centromere were found linking closely with the two resistance genes after the whole maize genome selection, the conclusion of two complementary dominant genes based on Mendel genetic analysis was verified. The genetic distances between markers and genes were calculated, which showed markersVIIbnlg1600 and phi075 flanking the resistance gene on chromosome 6 were 2-3cM and 4-5cM respectively, markers UMC1527 and UMC2020 flanking the resistancegene on chromosome 3 were 1-2 cM and 5-6 cM respectively.4. The function of the two genes was further studied based on the F2 plants genotype analysis and the comparison of field data investigated at different stage, the gene on chromosome 6 closely related to the resistance reaction at seedling stage when investigated one week later after inoculation.更多还原