Population structure and landscape genetics in the endangered subterranean rodent Ctenomys porteousi.

MAPELLI FERNANDO; MORA MATÍAS; MIROL PATRICIA; KITTLEIN MARCELO

CONSERVATION GENETICS

SPRINGER

Año: 2011 p. 165 - 181

1566-0621

The population fragmentation might have significant consequences for population genetic diversity and structure due to the effects of genetic drift and  gene flow. One essential concern in conservation genetics is that population fragmentation may critically compromise the long-term survival of many wild species. In order to devise adequate conservation and management strategies for endangered species, it is important to incorporate a reliable understanding of its spatial population structure, the existence of demographic partitions throughout its geographical range, and a characterization of the distribution of its genetic diversity. Moreover, in species that occupy fragmented habitats is essential to know how landscape characteristics may affect the genetic conectivity among populations. In this study we use eight microsatellite markers to analize population structure and gene flow patterns in all distributional range of the endagered rodent Ctenomys porteousi. Also, we use landscape genetics approaches to evaluate the effects of landscape configuration on the genetic connectivity among populations. In spite of geographical proximity of sampling sites (8-27 km between nearest sites) and the absence of marked barriers to individual movement, strong population structure and low values of gene flow were observed. Firstly, genetic differentiation among sampling sites was consistent with a simple model of isolation by distance (IBD), secondly, peripherical areas showed higher population differentiation than those sites located in central area of the species? distribution. Landscape genetics analysis indicated that habitat fragmentation at regional level has affected the distribution of genetic variation among populations. Distances of sampling sites to the area with higher habitat connectivity was the environmental factor that mostly had affected the population genetic structure in this species. In general, our results indicate strong genetic structure in C. porteousi, even at fine scale. Moreover, these results suggest that habitat fragmentation has reduced the population connectivity and has increased population differentiation on ecological time scales.