MORROW, PATRICE A.1 and JOEL P. OLFELT2.* 1Department of Ecology, Evolution and Behavior, 1987 Upper Buford Circle, University of Minnesota, Twin Cities, St. Paul, MN 55108; 2Department of Biology, St. Olaf College, 1520 St. Olaf Avenue, Northfield, MN 55057-1098. - Defoliation elicits long term disappearance of clones.
A large fraction of plant species in temperate, boreal and alpine
floras can propagate clonally allowing genets (genetic individuals) to
tolerate periods of reproductive failure, and often to obtain great
size and age. However, genets are vulnerable to herbivores, pathogens
and other localised disturbance. We monitored the status of 140
putative Solidago missouriensis clones in central Minnesota
before, during and after intense defoliation by insects. Five of the
putative clones, though apparently killed, reappeared 1 to >13 years
they disappeared, largely or completely recovering their original
territories within a single season. We tested the hypothesis that
territories were recovered by seedling establishment using 38 RAPD
markers obtained from 162 ramets collected from the recovered
territories. We detected a single genotype in each of three
territories, two genotypes in one territory, and eleven genotypes in
the fifth territory. The probability of detecting the identical
genotypes by chance is small (< 1 X 10-14). Since the
reoccupied territories are large relative to the area that could be
colonized by a single ramet in a single season, we conclude that
pre-and post-recovery clones are the same.
Key words: Clone, dormancy, RAPD markers, Solidago missouriensis