【作者】 郭伟；

【导师】 储昭辉； 丁新华；

【作者基本信息】 山东农业大学 ， 农业推广（专业学位）， 2012， 硕士

【摘要】 马铃薯(Solanum tuberosum)是世界上第四大粮食作物,由疫霉菌(Phytophthora infestans de Bary)引起的马铃薯晚疫病是马铃薯生产上的一种毁灭性病害。非寄主抗性指植物表现出的对绝大多数病原微生物的抗性。与寄主抗性相比,非寄主抗性更广谱稳定。烟草与马铃薯同属茄科植物,为马铃薯晚疫病的非寄主植物。本研究利用马铃薯晚疫病病原接种调查收集的烟草种质资源,通过鉴定不同类型的抗、感病资源为利用遗传学和分子生物学方法克隆抗病基因奠定基础,进而用于马铃薯抗晚疫病育种提供基因资源利用六个马铃薯晚疫病菌株,采用离体叶片接种的方法,建立烟草-马铃薯晚疫病菌非寄主互作体系,对收集的340种烟草种质资源进行抗病性检测。通过表型鉴定,结果分为五种表型：易感病、黄化并有水渍斑、侵染斑、褪绿、抗病,分别有植株1种、10种、6种、8种和315种。并对具有四种疑似感病表型的部分品种的叶片进行了台盼蓝染色,易感品种(心叶烟)观察到菌丝,黄化并有水渍斑和褪绿的品种观察到少量菌丝,有侵染斑的品种在接种部位出现了细胞坏死反应。接种不同苗龄的心叶烟,发现三四叶期比七八叶期感病程度有所加重,这表明在植物病原菌互作时,植物对病菌的抗性与其生长发育即苗龄相关,因此,确定后续接种体系应选用三四叶期嫩叶片进行接种。利用平板抑菌实验,分别提取了普通烟、本氏烟、番茄、马铃薯四种叶片的提取物,加入到培养基中,培养马铃薯晚疫病病原。结果发现不同叶片提取物对马铃薯晚疫病病原无明显影响,说明烟草非寄主抗性的产生与其次生代谢产物可能不具有相关性。利用筛选得到的易感品种心叶烟,与抗病品种进行杂交,配制了F1及F2群体,为进一步分离控制相关非寄主抗性基因奠定了基础。综上所述,我们通过离体叶片接种法,建立烟草-马铃薯晚疫病菌非寄主抗性筛选体系并通过筛选鉴定了一批携带马铃薯晚疫病非寄主抗性的遗传种质资源,尤其重要的是同时鉴定出24种表现部分易感症状和1种完全易感症状的烟草资源,为进一步鉴定相关关非寄主抗性相关基因奠定了遗传基础。同时,通过对抗性的分析,排除了烟草次生代谢物与非寄主抗性的关系,为“主效抗病基因说”决定该非寄主抗病性提供了支持。更多还原

【Abstract】 Potato(Solanum tuberosum) is the fourth crop in the world. Late blight, caused by Phytophthora infestans de Bary, is the most destructive disease. Nonhost resistance is an important type of plant disease resistance which governs defense responses to a broad spectrum of potential pathogen species. The nonhost resistance is more effective and durable resistance than host resistance in plant. Nicotiana tabacum is belong to Solanaceae plants as Solanum tuberosum. It was reported as non-host plant for Phytophthora infestans de Bary.In this study, we have screened out of potato late blight resistance varieties from a resource populations of tobacco, and characteration of different types of resistance and susceptible varieties which will help to clone the resistance genes by using combinated methods of genetic and molecular biology. Futher, these genes will provide as a resistance resource stock for potato breeding.By using Nicotiana tabacum and Phytophthora infestans as a nonhost plant-oomycete interaction system, we tested340species tobacco germplasm resources our laboratory own with six P. infestans isoltates with detached leaf method. The selected results can be divided in five phenotype:the susceptible species、the species with yellow and watermarks、the species with infection spot、the species with yellow、the disease-resistant species, one clones、 ten clones、six clones、eight clones and three hundred and fifteen clones respectively. We stained part species of four kind phenotypes with trypan blue, the susceptible species(Nicotiana glutinosa) can be observed lots of hyphae, the species with yellow and watermarks、the species with yellow can be observed a few of hyphae, the species with infection spot can be observed HR response.After inoculated Phytophthora infestans isolates at different seedling ages of3or4,7or8leaves Nicotiana glutinosa,we found that the susceptible sympton was decreased as the leaf age increase. Results indicated that this type of nonhost resistance is age-dependent. Also, this age-dependent resistance suggested to test the inoculation system better at3or4leaves age.The methanol extracts from leaves of the tobacco、benthamian、tomato、potato were examined for antibacterial activity on potato late blight. This suggested that nonhost resistant to P. infestans was not assoiciated with the secondary metabolic products.Crossing between the susceptible species(Nicotiana glutinosa) and some selected resistance varieties, we generated F2populations which lay a foundation to map and clone the R genes in the future.In general, we set up a nonhost plant-oomycete interaction system between Nicotiana tabacum and Phytophthora infestans with detached leaf assay. And chactered24partial susceptible varieties and1completely susceptible variety, which available to clone the nonhost R gene, Also, we excluded that this nonhost resistance directly related to plant metabolic products, provide evident to support the caused agent with mainly R gene as normal host resistance.更多还原