橡胶树白粉病越冬菌量的分子定量监测与病害预测研究

Powdery mildew, caused by Oidium heveae Steinm, is the most important rubber tree disease in China. It was demonstrated that overwintering inoculum of Oidium heveae, phenophase of rubber tree and temperature in winter and spring were the main factors related with the epidemics of the disease through field investigations, however, the quantitative relationships between these factors and disease severity were not clear. Additionally, five different symptom types could be occurred on rubber tree leaves based on phenophase and temperature and there was significant difference of viable inoculums among different symptom types. In this study, the effects of inoculum concentration, phenophase of rubber tree and temperature on the occurrence of rubber tree powdery mildew will be studied and models to describe the relationship between the factors and disease occurrence will be constructed. Overwintered inoculum of Oidium heveae at different epidemic regions in different years will be quantified by using Real-time RT-PCR which has been developed. The factors affecting the overwintered inoculum and disease epidemics will be determined. The disease prediction models will be constructed based on the overwintered inoculums, phenophase and weather variables. The anticipated research results will help to understand epidemics of the disease, and to predict and control rubber tree powdery mildew.

白粉病是我国橡胶树上为害最严重的病害，越冬菌量、胶树物候和冬春温度是影响病害流行的主要因子，目前关于各主要因子与病害之间的定量关系不准确，而且传统方法通过调查越冬老叶和冬嫩稍的发病率来确定越冬菌量，但白粉病在橡胶树叶片上的病斑类型有5种，且不同类型病斑上存活的菌量有很大差异，使我们对越冬菌量的调查不准确，从而影响对此病害的准确预测。本项目拟通过室内接种，重点研究菌量、胶树物候和温度等因子对病害发生的影响，明确其间的量化关系；借助申请人前期建立的基于RNA水平的橡胶树叶片中白粉菌的定量检测技术，对不同流行区的橡胶树白粉病越冬菌量进行多年多点的定量监测，研究气象因子对病原菌越冬的影响；结合病害调查，分析越冬菌量、胶树物候和气象因子与病害流行的关系，采用多种统计学方法构建病害预测模型并进行验证。研究结果为深入了解橡胶树白粉病的流行规律提供理论依据，同时为橡胶树白粉病准确预测和防治决策服务。

白粉病是我国橡胶树上为害最严重的病害，越冬菌量、胶树物候和冬春温度是影响病害流行的主要因子，目前关于各主要因子与病害之间的定量关系不准确，而且传统方法通过调查越冬老叶和冬嫩稍的发病率来确定越冬菌量，但白粉病在橡胶树叶片上的病斑类型有5种，且不同类型病斑上存活的菌量有很大差异，使我们对越冬菌量的调查不准确，从而影响对此病害的准确预测。本项目通过室内接种，研究了6个温度下3种物候期对橡胶树白粉菌分生孢子萌发、侵染及病害的影响，发现物候主要影响孢子萌发以后的生长阶段，而温度则对孢子各生长阶段均有显著影响，同时构建了相关模型，而指数模型可用来描述接种量与病情之间的关系；采用基于RNA水平的橡胶树叶片中白粉菌的定量检测技术和显微观察技术明确了橡胶树老叶和嫩叶上存活的白粉菌存在明显差异，对不同地区胶园的越冬菌量进行了定量检测，重点分析了温度对病原菌越冬的影响；调查了橡胶树白粉病的季节性流行动态并利用逻辑斯蒂模型对其进行了拟合，分析了越冬菌量、嫩叶期天数以及气象因子与病情之间的关系，构建了病害预测模型并对模型进行了检验。研究结果丰富了橡胶树白粉病的流行学理论，为病害预测和防治提供了依据。