东北水稻细菌病害监测预警及抗病资源评价

Rice Bacterial diseases, mainly caused by Xanthomonas oryzae pv. oryzae (XOO) and Xanthomonas oryzae pv. oryzicola (XOC), are rapid spreading diseases in northeast China, which would potentially and severely decrease rice production. But by now the relation between pathogens and rice varietes are not clear. In this project, a study that focus on pathogens group distribution\ genitic diversity\ virulence evaluating and predominate virulece gene groups and so on would be carried out, by 21 near-isogenic lines from IRRI\ local varieties amd imported varieties in Northeast China. Furthermore, the XOO and XOC pathogens derived from Northern and Southern China would be compared by IS1113 and so on primers, Arirulece gene familiy avrRxo1 and ax21 characteristics. This subject would not only provide pathogens theory on BB and BLS in Northeast China, but also play an important role on rice bacterial disease(s) early monitoring on rice production for national-wide rice food safety.

东北水稻产区少有发生的水稻白叶枯病（BB）和细菌性条斑病（BLS）近几年呈扩展蔓延趋势，并且相伴混合发生，对东北粮仓安全构成威胁。然而BB和BLS混合发生的病原学与品种间的关系并不清楚。本项目拟收集东北稻区白叶枯病菌XOO和条斑病菌XOC，以国际水稻所21个抗BB的近等基因系和东北稻区主要品种为材料，鉴别东北稻区XOO和XOC的群体分布、毒性组成和分化；利用IS1113等及无毒基因家族avrRxo1和ax21等特性，比较东北稻区XOO和XOC菌群与南方菌群的遗传多样性和变异性。本研究不仅将系统揭示我国东北稻区BB和BLS发生的病原学基础，而且将为我国东北稻区水稻细菌病害防控预警、监测提供理论依据。

本项目着重开展东北粳稻区白叶枯病生理小种分析、菌株遗传背景多样性分析、及品种资源对水稻白叶枯病病抗性做初步评定。155份水稻白叶枯病菌株，生理小种鉴定结果表明东北地区水稻白叶枯病菌生理小种型以R1型为主，出现频率分别为80.1%。选择东北稻区23株水稻白叶枯病菌，进行IS-PCR扩增和系统分析，结果显示在0.83遗传距离水平，23个菌株可划分为5个簇。利用分离的水稻白叶枯病菌株与粳稻品种接种互作，通禾855等品种表现较强抗谱。用9个中国水稻白叶枯病菌标准菌株对15份北方粳稻品种进行人工接种，结果显示除品种通系929表现中抗外，其他品种的抗性综合表现感病。研究结果表明北方菌株遗传多样性较复杂，北方品种抗性表现差异较大，但有较理想的抗原品种或材料存在。筛选出2份防治水稻白叶枯病较理想的药剂：20%叶枯唑可湿性粉剂（浙江省温州市展农化工农药厂，防效达到58.5%），72%农用硫酸链霉素可溶性粉剂（华北制药有限公司，达到42.2%）。