Burnett Jr., Robert K. , Mccormick, Melissa , Taylor, D. Lee , Whigham, Dennis .
Uncovering the relationship between Tipularia discolor and mycorrhizal fungi necessary for recruitment.
A major concern in orchid conservation has been knowing what factors limit recruitment from seed. Tipularia discolor (Orchidaceae) is listed as threatened or endangered in four states; however, little is known about the relationship between this orchid and its requisite mycorrhizal symbionts. Using newly developed taxon-specific PCR primers, we were able to gain insight into the factors that limit its recruitment despite limited knowledge about the basic biology of its fungal associates. T. discolor requires specific fungi for germination, but adults associate with a wide range of fungi. Protocorms (germinated seeds) are consistently associated with decomposing wood, and seeds do not germinate in the absence of appropriate fungi, but it is unknown whether germination is limited by availability of appropriate fungi, substrate, or both. We asked three main questions 1) Do mature T. discolor retain protocorm fungi into adulthood, or are protocorm and adult fungi mutually exclusive? 2) Are protocorm fungi limited to areas with decomposing wood? 3) Does the distribution of protocorm fungi in the soil limit the germination of T. discolor seeds? Molecular analysis showed that adult T. discolor can, but do not always, retain protocorm fungi into maturity. We also found that protocorm fungi were not restricted to, but were more common in, soils associated with decomposing wood. We conclude that T. discolor germination is jointly limited by decomposing wood and availability of appropriate fungi. Identification of the factors limiting T. discolor germination will be essential in conservation planning for imperiled Tipularia populations and will highlight the importance of fungi and decomposing wood for germination, growth, and reproduction.
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1 - Smithsonian Environmental Research Center, P.O. Box 28, 647 Contees Wharf Rd., Edgewater, MD, 21037, USA
2 - University of Alaska, Institute of Arctic Biology, 311 Irving I Building, Fairbanks, AK, 99775, USA
Presentation Type: Poster:Posters for Sections
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM