c8.12.8 – Nucleotidic variability of candidate genes related to drought and cold tolerance in Fagus sylvatica populations along altitudinal gradient

Lalagüe H (1), Garnier Géré P (2), González Martínez SC (3), Oddou Muratorio S (1), Vendramin GG* (4)

(1) INRA, Ecology of Mediterranean Forests Unit, Domaine Saint Paul, Site Agroparc 84914 Avignon, France; (2) INRA, Biodiversity Genes & Communities, 69 route d’Arcachon, 33612 Cestas, France; (3) Department of Forest Ecology & Genetics, Center of Forest Research, CIFOR-INIA, Carretera de la Coruña km 7.5, E28040 Madrid, Spain; (4) CNR, Institute of Plant Genetics, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
Collocazione: c8.12.8 – Tipo Comunicazione: Poster
8° Congresso SISEF *
Sessione 12: “Poster” *

Contatto: Giovanni Giuseppe Vendramin (giovanni.vendramin@igv.cnr.it)

Abstract: Trees make up around 90% of Earth’s biomass and are keystone species for a majority of ecosystems. Besides their ecological importance, natural populations of forest trees exhibit both striking phenotypic adaptations across their geographical range and a high genetic variability, which suggest important abilities of adaptation. Local adaptation arises through spatially varying selection, and can lead to genetic and phenotypic differentiation among populations, depending on the balance between selection, gene flow and population’s demographic history. The increasing availability of candidate gene sequences makes it possible to address the molecular basis of adaptation (through bottom-up approach) in natural populations on non-model species. Here, we present a population genomic study along two altitudinal gradients recently recolonised by Fagus sylvatica populations South-eastern France. Our objective is to identify candidate genes involved in the response of Beech to drought and cold stress and to characterise their variability at landscape scale across altitudinal gradients corresponding to climatic gradients. We selected 35 candidate genes fragments from a 35.000 ESTs databank according to their putative function. Then, the genes were sequenced in 96 individuals distributed in two populations (bottom, top) in each of two gradients (4 populations in total). The level and distribution of diversity at candidate genes within and among populations allowed us to to disentangle the roles of selection, gene flow and demographic history. We used both classical tests of departure of site frequency spectra from expectation and outlier detection tests, and accounted for the complex demographic history of the populations. These results are discussed in evolutionary terms, specifically the potential of Fagus sylvatica to adapt from standing genetic variation to drought and cold.

Parole chiave: Beech, Snp, Signature Of Selection, Candidate Genes

Citazione: Lalagüe H , Garnier Géré P , González Martínez SC , Oddou Muratorio S , Vendramin GG (2011). Nucleotidic variability of candidate genes related to drought and cold tolerance in Fagus sylvatica populations along altitudinal gradient . 8° Congresso Nazionale SISEF, Rende (CS), 04 – 07 Ott 2011, Contributo no. #c8.12.8