| Abstract Detail
Molecular Ecology and Evolution Fay, Michael F. [1], Leitch, Ilia J. [1], Kahandawala, Imalka [1], Lysak, Martin A. [1], Chase, Mark W. [1]. Genome size in Orchidaceae – variation, evolution, and consequences. GENOME size varies almost 2000-fold across the angiosperms. Most of the larger genomes are found in the monocots, notably in Alliaceae, Asparagaceae, Liliaceae, Melanthiaceae, and Orchidaceae. Orchidaceae show one of the widest intrafamilial ranges, with known 1C genome sizes ranging approximately 40-fold from c. 1.0 pg in many tropical epiphytic species to 38.8 pg in the diploid Cypripedium henryi. Robust phylogenetic hypotheses for Orchidaceae now give us the opportunity to examine the evolution of genome size across the family, to correlate its variation with life history and other traits, and to identify branches in the phylogenetic trees associated with increases and/or decreases in genome size. At current levels of sampling, large genomes (>10 pg) are known to occur in three out of the five subfamilies (Cypripedioideae, Epidendroideae, and Orchidoideae); in all cases these genomes belong to terrestrial species. Thus it appears that epiphytism may be limited to species with small/average genomes. Genomic studies in the slipper orchids and other monocots will be used to illustrate our current research involving investigation of retrotransposons and satellite DNA.
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Related Links:
Plant DNA C-values Database
1 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Richmond, Surrey, TW9 3AB, United Kingdom
Keywords:
Cypripedium
Orchidaceae
genome size
slipper orchids
retrotransposons.
Presentation Type: Oral Paper:Papers for Topics
Session: 26-8
Location: 350/Holt
Date: Monday, July 31st, 2006
Time: 3:45 PM
Abstract ID:101 |
