Systematics Section / ASPT
Tuthill, Dorothy E. .
Endophytes of Bromeliads.
ITS amplification of bromeliad leaf DNA for systematic work resulted in multiple products from each sample. These bands, once sequenced, turned out to belong to several fungi and a ciliated protist. The unexpected results led to further investigation into bromeliad endophytes. Leaves of 14 Bromelioideae species were collected from indoor and outdoor sites at Marie Selby Botanical Gardens, Sarasota, FL, and transported to Wyoming where they were surface sterilized, cut into 5x5 mm samples, and placed into petri dishes containing malt extract agar plus antibiotics. Fungi were allowed to grow out from the leaf samples. Fertile fungi were identified based on morphological characters. Fungi that remained sterile were regrown for DNA extraction and ITS sequencing. Sequences were subjected to BLAST search at the NCBI website to determine closest taxonomic affinities. Fifty fungal species were isolated from the 14 bromeliad hosts. Of these, 31 were identified based on fruiting structures, 18 required DNA-based identifications and one remains uncharacterized because its DNA has not been successfully amplified. Indoor and outdoor host species were found to harbor similar numbers of fungal species (5.6 and 5.3, respectively). Colonization rates (i.e., the percent of samples colonized) were also similar among indoor and outdoor hosts (88.7 and 82.7%, respectively). Thirty-seven of the fungal taxa were found in only a single host. Occasionally a unique endophyte had a high frequency of isolation, but more commonly these unique endophytes were isolated only a single time. Our sampling strategy did not include replicates of any host species, so we cannot determine if these rare fungi show host preference or are randomly scattered. Members of Xylariaceae were isolated from nearly all hosts. Commonly encountered genera included Cladosporium (6 species from 9 hosts), Penicillium (13 species from 7 hosts) and Nigrospora (2 species from 6 hosts).
1 - University of Wyoming, Department of Botany, 1000 E. University Ave., Laramie, Wyoming, 82071, USA
Presentation Type: Paper
Location: Cottonwood A (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 12:15 PM