|
|
|
Project Number: WVA00379 DIVERSITY AND INTERACTIONS OF BENEFICIAL BACTERIAL AND FUNGI IN THE RHIZOSPHERE Investigators: Morton, J. B.
Termination Date: 09/30/2000 Progress Report: In studies of diversity of arbuscular mycorrhizal fungi, communities were trapped from four sand dune habitats on three continents. Species of Glomus predominated in number and abundance. Indices of similarity were high (.23-.26) between sites, indicating a strong causal historical component. Assays for effectiveness of fungal isolates from three different communities on both soybean and red clover revealed that each community contained at least one highly effective fungus (improving P uptake, shoot biomass, or both). When isolates were mixed, beneficial effects were either neutral or additive. Responses of each community as a mixture was equal to or greater than the most effective individual isolates. These results suggest that management of native fungi may be a better strategy to enhance plant crop productivity than introduction of exotic isolates. In studies of the effect of iron on production of a fungal-generated glycoprotein important in soil aggregation, we found that 60 micromolar EDTA and 60 micromolar EDDHA stimulated more than 1.5 times the glycoprotein as lower soluble iron concentrations, based on immunological assays using an arbuscular fungus-specific monoclonal antibody. Unexpectedly, immunoreactive material (324-422 microg/g soil) was detected around roots of nonmycorrhizal sorghum, suggesting a plant-generated molecule of similar structure. This material did not vary with changes in iron concentration, and therefore may have distinct properties and function. Publications: Bever, J.D., and J.B. Morton. 1999. Heritable variation and mechanisms of inheritance of spore shape within a population of Scutellospora pellucida, an arbuscular mycorrhizal fungus. American Journal of Botany (in press). Morton, J.B., R.E. Koske, S.L. Sturmer, and S.P. Bentivenga. 1999. Protocols for measurement of diversity among arbuscular fungi. In: Biological Diversity Handbook Series: Standard Methods for Fungi. G. Mueller, A. Rossman, and G. Bills, eds. Smithsonian Institute Press, Washington, D.C. (in press). Schultz, P.A., J.D. Bever, and J.B. Morton. 1999. Acaulospora colossica sp. nov. from an old field in North Carolina and morphological comparisons with similar species, A. laevis and A. koskei. Mycologia (in press). Sturmer, S.L., and J.B. Morton. 1999. Scutellospora rubra, a new arbuscular mycorrhizal species from Brazil. Mycological Research (in press).
|