Stem and pith necrosis symptoms on tomato and midrib rot symptoms on lettuce were observed in West and East Azarbayjan of Iran. Infected organs of the plants were collected and bacterial strains were isolated on NA medium. Biochemical and physiological properties such as LOPAT test, fluorescent pigment production and utilization of carbon source, demonstrated that the strains were Pseudomonas cichorii. All strains were pathogenic on tomato and lettuce plants. To assess genetic diversity among the strains, BOX and ERIC-PCR analyses were employed. Clustering of ERIC and BOX-PCR results with UPGMA and Jaccard’s similarity coefficients showed that strains were clustered into two main groups at a similarity level of 52%. Strains of groups 1 and 2 isolated from lettuce and tomato, respectively. The gyrB, rpoD and 16S rRNA nucleotide sequences showed high similarity and the sequence similarity between the Iranian strains and P. cichorii reference strain were 98.9, 98.7 and 99.5%, indicating a close phylogenetic relationship between the strains. According to the past references and researches in Iran, this is the first report of isolation and identification of Pseudomonas cichorii, the causative agent of tomato pith necrosis and lettuce midirib rot in North West of Iran.

在伊朗西部和东部的阿扎尔巴扬观察到番茄的茎和髓坏死症状和生菜的中脉腐烂症状。收集植物的感染器官并在NA培养基上分离细菌菌株。LOPAT试验、荧光色素产生和碳源利用等生化和生理特性表明菌株为菊苣假单胞菌。所有菌株对番茄和生菜植物都是致病性的。为了评估菌株之间的遗传多样性，采用了 BOX 和 ERIC-PCR 分析。ERIC 和 BOX-PCR 结果与 UPGMA 和 Jaccard 相似系数的聚类表明，菌株以 52% 的相似度被聚类为两个主要组。分别从生菜和番茄中分离出的第 1 组和第 2 组菌株。该gyrB基因、rpoD和 16S rRNA 核苷酸序列显示出高度相似性，伊朗菌株与P. cichorii参考菌株的序列相似性分别为 98.9、98.7 和 99.5%，表明菌株之间存在密切的系统发育关系。根据伊朗以往的参考资料和研究，这是伊朗西北部番茄髓坏死和莴苣腐烂病原菌菊苣假单胞菌的首次分离鉴定报告。