Identification of poplar bacterial canker in Zanjan and Markazi provinces

In order to identify the bacterial canker of poplar, various poplar clones in Gilan, Zanjan, Markazi, Western Azerbaijan, Kermanshah and Hamedan provinces were visited. Branches of one to several years old and trunk with canker symptoms were collected. Bacteria were isolated from the collected samples from Zanjan and Markazi provinces on nutrient agar medium. The bacterial colonies were yellow and mucoid in nutrient agar sucrose medium. Pathogenicity of bacterial isolates was confirmed on poplar young shoots. All strains had hypersensitivity reaction on pepper and tobacco leaves. All bacterial isolates were gram-negative, oxidase, arginine dehydrolase, gelatin hydrolysis, lecithinase and urease negative, but catalase, esculin hydrolysis, levan production, tween-80 hydrolysis and production of H2S from cysteine and peptons were positive. All strains used sucrose, fructose, inositol, trehalose, galactose, sodium fumarate and sodium succinate. But they did not use l-arabinose, lactose, di-sorbitol, l-ramnose, raffinose, maltose, di-ribose and mellibiose. Based on their bacteriological properties and pathogenicity, all isolates were identified as Xanthomonas populi. The infection rate of poplar trees in Khosbijan station (Arak) were evaluated. Based on our results, the highest infection was observed in clones of, Populus nigra (P.n 56.52, P.n 56.21 and P.n 72.14) and the lowest infection was observed in clones of, P. alba (P.a 49.39) and P. betulifolia (P.b 56.21 and P.b 72.13) clones. The bacterium was not isolated from P.a 72.7 clone. This bacterium was not isolated from P.a 72.7 clone at Khosbijan station and from cankers of different poplar clones in Urmia, Kermanshah, Western Azerbaijan and Hamedan provinces.