Mycorrhizal Cheaters in the Monotropoideae: Costs, Benefits, and Life History Traits of an Unholy Alliance.

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

DEB-0108424 Bruns Epiparasitic plants are not photosynthetic, and they indirectly obtain sugars from green plants through a mycorrhizal fungus that is connected to both plants. This behavior makes them cheaters of one of the most widespread mutualisms in terrestrial ecosystems. Our goals are to understand the costs and benefits of epiparasitic plants to their direct fungal and indirect plant hosts, and to examine life history traits related to the establishment of epiparasite seedlings. We address these goals through four specific hypotheses related to conditional changes in the symbiotic continuum, to effects on host-fungal competitive interactions, and to ecological mechanisms for host specificity. These hypotheses are tested by coupling symbiotic germination experiments in the field with manipulative growth chamber experiments. We use precise molecular identification of fungi and plants in both settings. Results will provide an in-depth understanding of the nature of the interactions at the plant-parasitic end the mycorrhizal symbiosis, will yield novel data on specificity, germination, and development of these plants, and will further develop a unique experimental system of symbiotic cheating. This information will increase of our knowledge of mycorrhizal symbiosis, and will help us to manage populations of some of the rare and endangered species in the Monotropoideae.