Annette Kretzer

Annette received her "Diplom" in Biology from the University of Goettingen in 1989. Annette then continued her studies at Goettingen and received her PhD in Biology in 1993. Her thesis was on the degredation of isonicotinic acid by a Mycobacterium.

She worked as a postdoctoral fellow in the Bruns lab from 1993 to 1997 on the phylogeny of the genus Suillus sensu lato as well as on several aspects of ectomycorrhizal ecology. Following her time at Berkeley, Annette worked with Dr. J. Spatafora at Oregon State University on comparative population genetics of Suillus lakei and Rhizopogon vinicolor. In May of 2001, Annette moved to Syracuse New York.

Annette's current research focuses on the question whether or not the diversity of bacterial communities associated with ectomycorrhizae is partitioned between different species of ectomycorrhizal fungi. Ectomycorrhizae are symbioses between many important forest trees including all of the Pinaceae and fungi mostly from the Basidiomycota. The benefits of the symbiosis to both parties are that the tree hosts provide carbohydrates to the fungi while the fungi facilitate nutrient uptake. Ectomycorrhizal fungi are taxonomically much more diverse than their tree hosts, but it remains largely unclear whether the different species of fungi differ in the functions they fulfill for the tree hosts and the forest ecosystem or whether they are "functionally redundant". In addition to trees and fungi, bacteria have also been shown to live in close association with ectomycorrhizae, but have rarely been investigated, and it remains largely unclear whether and how they affect the functioning of the symbiosis in a natural environment. As a first step in assessing the potential influence of bacterial populations on the functional diversity of ectomycorrhizal fungi associated with Douglas-fir, Annette plans to study how bacterial diversity is structured between different species of fungi and different individuals within a species. To answer these questions, she will take advantage of molecular methods developed over the last ten years to identify plant host and fungal species from EM samples collected in the field. Furthermore, she will adapt recently developed methods for measuring bacterial diversity to EM systems; these methods employ total community DNA extraction, PCR amplification of partial 16S rDNA sequences with fluorescent primers, and fingerprinting by separation on acrylamide gels.


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