Abstract
Bacteria were isolated and characterized from uncolonized soil, nonmycorrhizal and mycorrhizal short roots, and soil-colonizing external mycelium from intact Pinus sylvestris - Suillus bovinus and Pinus sylvestris - Paxillus involutus mycorrhizospheres developed in microcosms containing dry pine forest humus or nursery peat. Total numbers of colony-forming units (CFU/mg dry weight) in the different locations from all ectomycorrhizospheres indicated an overall bacterial-enrichment gradient towards the roots, whereas sporeformers were more evenly distributed. Fluorescent pseudomonads were commonly isolated from all mycorrhizosphere locations in nursery peat, but they were nearly absent from the forest humus community. In contrast, sporeformers were more abundant at all locations in the latter growth substrate. The bacterial species composition of forest and nursery mycorrhizospheres was clearly divergent when characterized according to their carbon source utilization patterns in Biolog®GN or GP microplates. Factorial-designed ANOVA of a principal component analysis of the carbon source utilization data showed significant differences between isolates from the two soil types and, to a lesser extent, between S. bovinus and Paxillus involutus mycorrhizospheres. Bacterial communities from mycorrhizospheres and uncolonized soil were distinguished by their preferential utilization of carbohydrates and organic and amino acids, respectively. Suillus bovinus associated bacteria appeared to favour mannitol and Paxillus involutus associated bacteria appeared to favour fructose as carbon sources. This study demonstrates the combined effect of soil type, fungal symbiont, and precise location on bacterial communities associated with Pinus sylvestris ectomycorrhizospheres.Key words: Biolog, carbon source utilization, ectomycorrhiza, Scots pine, soil bacteria.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.