|Van Berkum, Peter|
Submitted to: Abstract of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2001
Publication Date: 10/22/2001
Technical Abstract: Metal contamination can affect the diversity of microbes living in soil. The phenotypic and genetic characteristics of Rhizobium leguminosarum bv trifolii isolated from indigenous plants found at a metal contaminated and a control site, or from plants used during most probable number determinations of rhizobia in the metal contaminated soil, were compared. Variations across isolates in fingerprints patterns after BOX-PCR were used for genetic characterization. Metal phenotype of each isolate was determined on Petri plates. The presence of high concentrations of Cd and Zn in the high metal soil led to changes in the soil population of R. leguminosarum. The overall diversity in R. leguminosarum as shown by the analysis of DNA patterns obtained by BOX-PCR was not affected by the presence of higher metal concentrations in the high metal soil. Higher metal tolerance and higher diversity in phenotypes were observed in the high metal soil and were correlated with a decrease in metal sensitive phenotypes. Some metal sensitive and metal resistant rhizobia unable to form nodules in natural conditions were found to be able to survive in soil probably within microniches protecting them from heavy metal toxicity and from predation.