J. Caujape-castells et al., Contrasting patterns of genetic structure in the South African species Androcymbium bellum, A-guttatum and A-pulchrum (Colchicaceae), BIOCH SYST, 27(6), 1999, pp. 591-605
Spatial autocorrelation analyses on genetic variability from three isozymic
loci was used to explore the presence of possible patterns of genetic stru
cture in four populations representing the South African species Androcymbi
um bellum, A. guttatum and A. pulchrum. Consistent profiles of short-distan
ce genetic structure are only detected in patchy populations (A. bellum and
A. guttatum), regardless of the sharp ecological differences between them.
In the absence of microhabitat heterogeneity, our result strongly suggests
that the predominant action of assortive mating (in A. bellum) and of vege
tative reproduction (in A. guttatum) fostered the creation and enhancement
of physical clumps that correspond to genetically related plants. A much lo
wer incidence of both clonal propagation and outcrossing in the two continu
ous populations of A. pulchrum examined explains why isozymic variability i
s not spatially structured in this species. (C) 1999 Published by Elsevier
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