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

FERNÁNDEZ, M.; EZCURRA, C., ; QUIROGA, M. P. ; PREMOLI, A. C.

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 ofSenecio carbonensis, a narrow endemic from high elevations of the southern Andes, andcompared it to Senecio peteroanus, a closely related widespread congeneric species. UsingANOVAs and discriminant analysis we showed that populations of S. carbonensis weremore similar to each other in their morphology, had comparatively limited reproductivecapacity and presented lower plant density and more reduced plant cover than populationsof S. peteroanus. Similar high genetic variation was found at the population andspecies level in both species, based on isozyme variation at 14 and 11 putative gene locithat were resolved in S. carbonensis and S. peteroanus, respectively. The two species weregenetically distinct. However, the small genetic distance between populations of eachspecies suggests that either they were recently founded and that genetic drift did not havetime 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 maylimit its extension and abundance. In contrast, high genetic variation at the populationlevel is probably favored by self-incompatibility. Despite the restricted geographicaldistribution and low plant density of S. carbonensis populations, genetic characteristicsdo not seem to be limiting their long-term persistence. This information suggests thatpopulations of S. carbonensis are not at risk of extinction as a result of genetic factors,although it is important to study and monitor population dynamics to further assess thedegree of recruitment through time.