MUTATIONAL ANALYSIS OF RACE SPECIFIC RESISTANCE

种族特异性抗性的突变分析

• 批准号: 3297411
• 负责人: Shauna C. SOMERVILLE
• 金额: $ 7.31万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-01 至 1991-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3297411
• 关键词: Ascomycetes; R factors; alleles; chromosome complement; cytogenetics; cytology; disease /disorder proneness /risk; electron microscopy; freeze etching; gene expression; genetic crossing over; genetic manipulation; genetic recombination; grain; host organism interaction; inbreeding; molecular cloning; mutagen testing; plant diseases; plant genetics; plant growth /development; species difference; temperature sensitive mutant; virulence

Plant breeders have identified resistance alleles in wild plant isolates and have exploited these alleles in breeding modern, disease-resistant cultivars. Insight into the genetic basis of resistance and susceptibility in plants may provide models for the establishment of human diseases. We have chosen to study the powdery mildew disease of barley, caused by the obligate ascomycete, Erysiphe graminis f. sp. hordei. Barley - E. graminis interactions are characterized by extreme specificity. That is a given barley line is resistant to a specific set of E. graminis races, and conversely a given race is virulent on a limited, specific set of barley lines. A widely accepted hypothesis in the plant pathology literature, the "gene- for-gene" hypothesis, suggests that the minimum number of genes which distinguish resistance from susceptibility is one. Our preliminary data suggest that the "gene-for-gene" hypothesis does not adequately describe race-specific resistance to E. graminis in barley. In the present study the number of genes conditioning resistance to a specific E. graminis race will be determined by mutational analysis. We shall screen a mutagenized population of resistant barley seedlings for susceptible mutants. Detailed cytological analysis of the infection sequence of susceptible barley mutants will provide information about the contribution of each disease reaction gene to the establishment of incompatible relationships and the expression of resistance. Once the genetic basis of resistance is adequately understood strategies for cloning resistance genes can be devised. As a consequence of such knowledge more rational approaches to the development of resistant barley cultivars using variability in disease resistance extant in wild isolates, and in the future, variability generated by in vitro manipulation of cloned disease reaction genes may be undertaken.

植物育种家已经在野生植物中发现了抗性等位基因