Abstract:

For elucidating the brown stripe pathogen of rice and differentiating it from watermelon blotch bacterium,four out of six bacterial strains isolated from the diseased rice seedlings were compared with three standard reference strains of Acidovorax avenae subsp.avenae and two standard reference strains of A.avenae subsp.citrulli by the bacteriological tests,colony morphology,pathogenicity,Biolog,FAME analysis,electromicroscope observation and nested-PCR.It has confirmed that A.avenae subsp.avenae is the causal agent of bacterial brown stripe of rice.The results also showed that FAME analysis misidentified some strains of A.avenae subsp.avenae as A.avenae subsp.citrulli whereas Biolog and the nested-PCR were the best way for distinguishing the two bacterial pathogens.

Key words: bacterial brown stripe of rice, phenotypic identification, electromicroscope observation, nested polymerase chain reaction, Acidovorax avenae subsp.avenae, Acidovorax avenae subsp.citrulli

摘要： 为明确从褐条病稻苗上分离出来的病原细菌并与西瓜果斑病菌相区分, 对该病原特性进行了研究。分离获得6株褐条病致病菌，其中4株经主要细菌学特性、菌落形态、致病性、Biolog、脂肪酸分析（FAME）、电镜观察、NestedPCR鉴定及与3株水稻细菌性褐条病标准菌株和2株西瓜果斑病标准菌株的比较，证实了该病是由单极鞭革兰氏阴性细菌〖WTBX〗Acidovorax avenae〖WTBZ〗 ssp. 〖WTBX〗avenae〖WTBZ〗引起的。FAME将水稻细菌性褐条病菌误鉴定为西瓜果斑病菌，而用Biolog和nested-PCR鉴定能得到准确的鉴定结果。

关键词: 水稻细菌性褐条病, 表型鉴定, 电镜观察, 巢式聚合酶链式反应, 褐条病病菌, 西瓜果斑病菌