ESSELMAN, ELIZABETH J., DANIEL J. CRAWFORD*, SOREN BRAUNER, TOD F. STUESSY, AND MARIO SILVA O. Department of Biologcial Sciences, Southern Illinois University, Edwardsville, IL 62026.Department of Plant Biology, The Ohio State University, Columbus, OH. Department of Biology, Ashland University, Ashland, OH 44805. Department of Higher Plant Systematics and Evolution, University of Vienna, Vienna, Austria. Departamento de Botanica, Universidad de Concepcion, Concepcion, Chile. - Allozyme and RAPD marker diversity within and divergence among species of Dendroseris (Asteraceae).
Allozymes and Random Amplified Polymorphic DNA (RAPD) markers were
used to measure genetic diversity within and divergence among species
of Dendroseris (Asteraceae), a genus endemic to the Juan
Fernandez Islands, Chile. Genetic identities between species at
allozyme loci range form 0.73 to 0.99, with species from the same
subgenus having the highest identities. Dendroseris
neriifolia has low identities with the other seven species
examnined, which is concordant with other molecular data suggesting
that it is a divergent element in the genus, including the subg.
Rea where it is now placed.Species of Dendroseris are
like many other insular endemics in having higher identities than most
congeners of continental areas. In several instances, species with
high similarities in RAPD banding patterns also have high genetic
identities at allozyme loci, and relationships inferred from RAPD
bands are more similar to results for morphology, chloroplast DNA
restriction sites and ITS sequences than are those from allozyme
allele frequencies. Levels of allozyme diversity in species of
Dendroseris are low even when compared to other island
endemics, and this may be a result of the very small population sizes
for all species. RAPD markers are more sensitive than allozymes for
distinguishing individuals within the same populations and species.
Relative levels of diversity for allozymes and RAPD bands are similar
for all taxa except one; this indicates that the two types of
molecular markers are providing comparable estimates of relative
genetic variation in these rare insular endemic species of
Dendroseris.
Key words: allozymes, Dendorseris>, islands, RAPD markers