Characterisation of a genetic region that conditions resistance to viral fungal and plasmodiophorid plant pathogens

植物抗性（R）基因是害虫综合治理战略的重要组成部分，减少了对杀真菌剂和杀虫剂处理的依赖。最近的工作在我们的财团已经导致了R基因区域的条件下，甜菜的病毒，真菌和plasmodiophorid病原体的抗性的鉴定。这种广谱抗性可以由许多紧密连锁的R基因或单个新基因赋予。随后对基因组的扫描揭示了许多与广谱R基因位点相互作用以降低疾病水平的位点。该项目的目的是从结构、与次级遗传基因座的相互作用及其在田间控制疾病的能力等方面，确定甜菜第四号染色体中与抵抗各种病原体有关的区域。预计该项目产生的信息和材料将用于甜菜育种者的标记辅助选择，并可能用于随后工作中抗性基因的图位克隆。因此，该项目的另一个目的是促进进一步利用这一耐药性位点。在第1年，将在受控环境试验中评估对不同病原体的抗性分离的大型植物种群的抗病性。行业合作伙伴将对这些群体进行分子标记分析，以便生成QTL图谱。这些图谱将用于鉴定次级相互作用基因座，并确定含有抗性等位基因的IV号染色体区域。在该区域显示重组的个体植物将用于产生测交家族以进行精细作图。在第2年，将生成一组多态性SNP标记，并在感兴趣的区域内作图。在第3年，将在田间生长季节评估测交家系的抗病性，从而确定IV号染色体抗性随时间的效力。该表型信息将与SNP标记数据组合以产生广谱抗性基因座的孟德尔化精细图谱。这项工作的结果和解释将提交给同行评审期刊。

Plant resistance (R) genes form an important component of integrated pest management strategies, decreasing reliance on fungicide and insecticide treatments. Recent work within our consortium has resulted in the identification of an R gene region that conditions resistance to viral, fungal and plasmodiophorid pathogens of sugar beet. This broad-spectrum resistance could be conferred by a number of tightly-linked R genes or by a single, novel gene. Subsequent scans of the genome revealed a number of loci that interacted with the broad-spectrum R gene locus to reduce disease levels. The aim of the project is to characterise the region of Beta vulgaris chromosome IV involved in resistance to diverse pathogens, in terms of its structure, its interaction with secondary genetic loci and its ability to control disease in the field. It is anticipated that the information and materials generated within the project will be used for marker assisted selection by sugar beet breeders and potentially for map-based cloning of the resistance gene(s) in subsequent work. A further aim of the project therefore is to facilitate further exploitation of this resistance locus. In year 1, large plant populations which segregate for resistance to diverse pathogens will be evaluated for disease resistance in controlled environment tests. Industry partners will conduct molecular marker analysis on these populations so that QTL maps can be generated. These maps will be used to identify secondary, interacting loci and to define a region of chromosome IV that contains the resistance alleles. Individual plants that show recombination in this region will be used to generate testcross families for fine mapping. In year 2, a set of polymorphic SNP markers will be generated and mapped within the region of interest. In year 3, the testcross families will be evaluated for disease resistance over a growing season in the field, allowing the efficacy of chromosome IV resistance through time to be determined. This phenotypic information will be combined with the SNP marker data to generate Mendelised, fine maps of the broad-spectrum resistance locus. The results and interpretation of this work will be submitted to peer review journals.