Genetic variation relevant for the conservation of the narrow 1 endemic Senecio carbonensis (Asteraceae) from the southern Andes

MARTINA FERNÁNDEZ; CECILIA EZCURRA; MARIA PAULA QUIROGA; ANDREA C. PREMOLI

PLANT SPECIES BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011 vol. 26 p. 145 - 157

0913-557X

We studied morphological variation, reproductive biology, and genetic structure of Senecio carbonensis, a narrow endemic from high elevations of the southern Andes, which was compared to S. peteroanus, a closely related widespread congeneric species. ANOVAs and discriminant analysis showed that the populations of S. carbonensis were more similar between each other in their morphology, had comparatively limited reproductive capacity, and presented lower plant density and more reduced plant cover than those of S. peteroanus. Similar high genetic variation was found at the population and species level in both species, based on isozyme variation at 14 and 11 putative gene loci that were resolved in S. carbonensis and S. peteroanus, respectively. The two species were genetically distinct. However, the small genetic distance between populations of each species suggests that either they were recently founded and that genetic drift did not have time to promote divergence, or that its effects are masked by significant current gene flow. These results show that ecological and reproductive characteristics of S. carbonensis may limit its extension and abundance. In contrast, high genetic variation at the population level is probably favoured by self incompatibility. Despite the restricted geographical distribution and low plant density of S. carbonensis populations, genetic characteristics do not seem to be limiting their long term persistence. This information suggests that populations of S. carbonensis are not at risk of extinction due to genetic factors, although it would be important to study and monitor population dynamics to further assess degree of recruitment through time.