Decrypting spatial structures of genetic variability for the conservation of native forests in Argentina

TEICH, I.; BRUNO, C.; VERGA, A.

Florianópolis

Conferencia; XXVth International Biometric Conference; 2010

La Región de Brasil (RBras) y la Región de Argentina (RArg).

The spatial detection and location of genetic discontinuities between biological entities (populations or individuals) is essential in landscape genetics, a new discipline that aims to provide information on how landscape and environmental features influence population genetic structure. These studies have great applicability in conservation biology and are of particular relevance when applied on native forests. Most methods in spatial statistics are devoted to quantitative and univariate data whereas the nature of genetic data is categorical and strongly multivariate. Therefore, to infer the location of genetic discontinuities from individual geo-referenced multi-locus genotypes, without a priori knowledge on population units and limits, it is fundamental to couple different methodological approaches. Even when applying methodologies that focus on the part of the variability which is spatially structured, like the recently developed Spatial Principal Components Analysis (sPCA), the spatial dependence may not be statistically significant due to sampling design and the co-existence of different genetic spatial structures. In this work we propose the combined use of dimension reduction techniques, like sPCA with a classical geostatistical perspective, and analyze how power affects the capacity to detect global spatial structures. We study the spatial genetic structure of 87 trees that belong to a hybrid swarm of Prosopis sp. sampled in Córdoba (Argentina) and genotyped at six microsatellites. Genetic discontinuities were spatially located and the statistical significance of the spatial dependence was tested. We also discuss about the type of biological information that can be extracted.