Population subdivision and genetic diversity in two narrow endemics of Antirrhinum L.

Mateu-Andrés, I.; Segarra-Moragues, J.G.. Population subdivision and genetic diversity in two narrow endemics of Antirrhinum L.. Molecular Ecology. 2000, Vol. 9(12), p. 2081-2000.

Genetic diversity and its partition within and among populations and families of two species
of
Antirrhinum
L.,
A. charidemi
Lange and
A. valentinum
F.Q., have been studied. Both
species are narrow-range endemics, self-incompatible, ecologically specialized and form
small isolated populations. Despite these similarities, the species differ markedly in the
distribution of genetic diversity. In
A. valentinum
, 61.64% of the total variation was distributed
among populations, whereas in
A. charidemi
it was only 8.55%.
A. charidemi
showed little
population divergence (
G
ST
= 0.0542) relative to
A. valentinum
(
G
ST
= 0.4805). In neither
species was within-population genetic diversity correlated with population size, nor were
there significant correlations between genetic and geographical distances. These results are
discussed in relation to differences in flowering time and habitat continuity. They suggest
that caution should be taken when making generalizations about levels of genetic variation
and patterns of plant reproduction, life history and geographical distribution.