Fluctuation of endophytic bacteria and phytoplasmosis in elm trees.

A total of 658 heterotrophic bacterial colonies isolated from phloem tissues of roots and branches in four months (April, June, September and December) from two elm plants, one of which affected by phytoplasmosis, were typed by means of ARDRA. This analysis revealed the existence of a high degree of variability within the community and was able to detect 84 different ARDRA groups. The Analysis of Molecular Variance was applied to ARDRA patterns to analyze the differentiation between communities isolated from the various samplings. Data obtained were compared with those from a previous work (Mocali et al. 2003). Results indicated that plants with symptoms of phytoplasmosis showed marked alterations in the extent of the fluctuations of the community along the seasons in the different plant organs.