Abstract Detail

Recent Topics Posters

Chau, John [1], Douglas, Norman [2].

Do endophytes in Magnolia grandiflora leaves produce false bands in AFLP fingerprints from leaf DNA extractions?

The AFLP fingerprinting technique is a powerful and commonly used method of detecting genetic polymorphism. However, false bands may result from contamination due to its nonspecific nature. Endophytes, ubiquitous fungi that colonize plant tissues asymptomatically, are a possible source of contamination in plant DNA extractions, especially if older plant tissues are used, since they have been shown to have greater abundances of endophytes. In this study, AFLP fingerprints were obtained for leaf segments from a single Magnolia grandiflora tree. Endophytes were cultured on malt extract agar from adjacent leaf segments and subsequently identified using ITS sequences. AFLP fingerprints were obtained for endophyte isolates from the most common taxa. Older leaf segments, those that had emerged in the past two years, were found to have a significantly higher mean number of endophyte isolates per segment (2.72) than leaf segments that had emerged in the current year (1.31). A significantly higher mean proportion (0.98) of older leaf segments yielded at least one endophyte isolate as compared with the proportion leaf segments that had emerged this year (0.54). The number of bands seen in the AFLP fingerprints of leaf segments showed a positive correlation with the number of endophyte isolates yielded by the segment (R2 = 0.0032) and a negative correlation with leaf age (R2 = 0.0251), although neither trend was significant. Further analyses taking into account band intensity of leaf AFLP fingerprints and the use of endophyte AFLP fingerprints to look for specific bands from possible contamination in leaf fingerprints may help explain the observed variation in AFLP fingerprints of leaf segments.

1 - Cornell University, Ithaca, NY, 14850
2 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA

Keywords:
AFLP
fingerprinting
contamination
endophytes
leaf age
Magnolia grandiflora.

Presentation Type: Recent Topics Poster
Session: 33-130
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM
Abstract ID:676