江苏省水稻品种对水稻细菌性条斑病抗性鉴定及评价

为明确江苏省水稻条斑病菌致病力分化状况和不同类型水稻品种对条斑病抗感特性,在孕穗期采用针刺接种法对徐淮稻区2007—2009年采集分离获得的45株条斑病菌进行致病力测定,根据病原菌在6个水稻鉴别品种IRBB4、IRBB5、IRBB14、IRBB21、IR24和金刚30上的抗感反应划分致病型,从中选择具有代表性的3种不同致病型条斑病菌,并鉴定了240个不同类型的水稻品种对条斑病的抗感性。根据菌株在鉴别品种上的抗感反应将供试菌株划分为8个致病型,其中优势致病型为C3致病型,所占比例为35.5%;大多数菌株与鉴别品种间表现出弱互作关系,少数菌株表现出强互作关系。粳稻品种对条斑病的抗性明显高于籼稻,但常规粳稻和杂交粳稻对强致病力菌抗性比例仅为59.8%和37.5%。表明水稻细菌性条斑病流行仍具有潜在的威胁。

Evaluation of rice varieties resistant to bacterial leaf streak in Jiangsu

To identify virulence of Xanthomonas oryzae pv.oryzicola and different rice varieties resistant or susceptible to bacterial leaf streak from Jiangsu Province, differentiation in the virulence of 45 isolates of X.oryzae collected in Xuhuai area from 2007 to 2009 were identified with six rice cultivars (IRBB4, IRBB5, IRBB14, IRBB21, IR24 and Jingang 30) using the inoculation method of leaf-needling at booting stage. Three pathogen strains of different virulences were selected to identify the resistance of 240 rice varieties against bacterial leaf streak. The 45 pathogen strains were classified into 8 pathotypes and the predominant pathotype was C3 (35.5% of the total strains); weak interaction was observed between pathogen strains and rice varieties in the majority of isolates, but the minority showed specific interaction. The results of resistance identification suggested that the resistance of Japonica rice to bacterial leaf streak was stronger than that of Indica rice, but conventional Japonica rice and Japonica hybrid rice showed resistance to stronger pathotype strain b5-16, only accounting for 59.8% and 37.5%, respectively. It suggests that bacterial leaf streak remains to be an epidemic potential threat to rice.