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Seven Gram-negative bacterial strains were isolated from oozing bark canker of poplar (Populus¾euramericana) trees in Hungary. They showed high (.98.3 %) 16S rRNA gene sequence similarity to Lonsdalea quercina; however, they differed from this species in several phenotypic characteristics. Multilocus sequence analysis based on three housekeeping genes (gyrB, atpD and infB) revealed, and DNA-DNA hybridization analysis confirmed, that this group of bacterial strains forms a distinct lineage within the species Lonsdalea quercina. A detailed study of phenotypic and physiological characteristics confirmed the separation of isolates from poplars from other subspecies of L. quercina; therefore, a novel subspecies, Lonsdalea quercina subsp. et al., 1996), and Brenneria goodwinii infects Q. robur and Q. petrea .Since 2009, a specific symptom has been detected in poplar (Populus6euramericana) stands in the central part ofHungary. The bark of symptomatic trees is vertically cracked, and a sticky, brown-coloured fluid oozes from the canker. Typically, huge numbers of the free-living, bacteriophagous nematode Panagrellus redivivus feed on the oozing fluid and on the creamy mass under the cracked bark, suggesting that high numbers of bacteria are present in the bark canker. During 2011, many bacterial strains were obtained from oozing bark cracks and creamy slime under the bark of poplar trees at three different sites in Hungary. The isolates were grouped by morphological and phenotypic characteristics (API 20E and Biolog GN2 analyses). Only the members of one morphologically homogeneous group were present in all samples. This group was tentatively identified as L. quercina (formerly Brenneria quercina) based on partial 16S rRNA sequencing; however, it differed from L. quercina in several phenotypic traits. In the present study the taxonomic position of isolates belonging to this group was investigated using multilocus sequence analysis (MLSA) of three housekeeping genes (gyrB, infB and atpD), DNA-DNA hybridization analysis and phenotypic assays.In total, seven strains (including NY060 T

Research and Extension Centre for Fruit Growing, Vadastag 2, H-4244 Ú jfehé rtó , HungaryDuring the characterization of symbiotic bacteria of Hungarian entomopathogenic nematode isolates, a number of bacteria (including strain 3107 T ) isolated from Heterorhabditis downesi and Heterorhabditis megidis showed only moderate 16S rRNA gene sequence similarity to the type strains of all described Photorhabdus species and subspecies. On the basis of the 16S rRNA gene sequence, the phylogenetic relationships of these isolates were uncertain, because of the low bootstrap values. Using gyrB sequences for phylogenetic analysis, these isolates were shown to be part of the species Photorhabdus temperata, with clear separation from both Palaearctic and American strains (phylogenetic distances are 6.9 and 7.9 %, respectively). Physiological properties and carbon-source utilization profiles supported the phylogenetic position of these strains; therefore, a novel subspecies, Photorhabdus temperata subsp. cinerea subsp. nov. is proposed, with the type strain 3107 T (5DSM 19724 T 5NCAIM B 02271 T ).

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