Phylogeography of evergreen Nothofagus from Patagonia (Subgenus Nothofagus)

ACOSTA M. C.; PREMOLI, A. C.

Bariloche (Río Negro)

Congreso; VI Southern Connection Congress; 2010

Southern Connection

Geological forces have shaped the geography of the austral continents as well as the distribution of plant populations and their genetic patterns. Patagonia has suffered the impact of ancient events such as plate tectonics, sea-level changes, and even more recent Pleistocene glaciations. The aim of this study is to analyze the levels and distribution of chloroplast DNA variation in populations of evergreen Nothofagus in relation to the historical processes that occurred in Patagonia. We sampled 15 populations of N. betuloides, 44 of N. dombeyi, and eight of N. nitida along their current ranges of distribution. Non-coding regions of chloroplast DNA from 120 individuals were amplified by polimerase chain reaction (PCR) using psbB-psbH, trnL-trnF and trnH-psbA universal primer pairs. Relationships among haplotypes were analyzed by means of phylogenetic analyses of maximum parsimony, Bayesian inference, and haplotype median-joining network. We found 19 haplotypes distributed in three major clades separated latitudinally. Greatest haplotype diversity was found in Coastal Cordillera and Chiloé Island. Our results propose that populations of evergreen Nothofagus suffered significant latitudinal disjunctions due to geographic barriers as paleobasins. We hypothesize that Coastal Cordillera was a potential corridor and refuge including Chiloé Island which has probably been in close contact to continental southern areas in the past.