Management of genetic resources: definition of genetic zones in American Nothofagus forests. Genetics of Fagaceae and Nothofagaceae.

AZPILICUETA, M.M.; GALLO, L A; VAN ZONNEVELD, M; THOMAS, E.; MORENO, C; MARCHELLI, P

Bordeaux

Congreso; IUFRO 2012; 2012

INRA

The conservation and management of a species can be better organize if information on genetically homogeneous units based on the distribution of its genetic, morphological and adaptive variation is available. The identification of these homogeneous units has practical importance in the transfer of germplasm within and between regions, for example in reforestation or restoration activities. Genetic zones are defined as genetically homogeneous regions within which propagation material can be transferred, minimizing the occurrence of changes at the genetic structure level. Our main goal is to define genetic zones for Nothofagus nervosa and Nothofagus obliqua within their Argentinean natural distribution range in conjunction with considerations related to expected predictions of global climatic change. A total of 823 individuals belonging to 24 populations (14 of N. nervosa and 10 of N. obliqua, μ= 34 ± 5) were genotyped based on the information provided by seven nuclear microsatellite loci. Genetic patterns were visualized in maps using DIVA-GIS. The geographic clustering encountered by the application of a Bayesian approach was analysed in conjunction with diversity parameters, chloroplast DNA and isozyme information. Six and five genetic zones were identified in N. nervosa and N. obliqua, respectively. Genetic zones were consistent with the management history of the species, and also have a geographic congruence. The distribution pattern of allelic richness seemed to be closely associated with the glacial history of the species within the region. Therefore, higher allelic richness values were located in the surroundings of areas identified as potential glacial refuges. Based on ecological niche modelling, potential suitable areas for both species were identified which can in turn represent potential ecological conditions for plantation. We expect this information should constitute a valuable tool for the identification of seed transfer zones, recruitment assistance and plantation activities within domestication programs at both species in Argentina.