Evidences of local adaptation and stabilising selection on quantitative traits in populations of the multipurpose American species Acacia aroma (Fabaceae)

CAROLINA L. POMETTI; CECILIA F. BESSEGA; ANA M. CIALDELLA; MAURICIO EWENS; BEATRIZ O. SAIDMAN; JUAN C. VILARDI

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2019 vol. 191 p. 128 - 141

0024-4074

Acacia aroma is important as forage, as goats and sheep feed on the leaves and pods of natural populations. Economically and ecologically important quantitative traits are related to life history, fruit size and shape and leaf size and shape. Substantial variation is observed for these traits in natural populations, suggesting the possibility of a genetic basis useful for selection programmes. Our objective was to detect signals of selection on 12 phenotypic traits in 170 individuals belonging to seven populations of A. aroma in the Chaco Region evaluated in Argentina. The phenotypic traits were compared with molecular markers assessed in the same populations. Here, we search for signatures of natural selection by comparing quantitative trait variation to neutral genetic variation through the PST-FST test.We further test for differences among populations for the 12 phenotypic traits, association of phenotypic variation with environmental variables and geographic distances, and we compared the power of discrimination between phenotypic and AFLP data set. PST-FST test suggested directional selection for tree height and stabilising selection for the remaining traits. ANOVAs showed significant differentiation for eight phenotypic traits. These results suggest selecting among provenances as a management strategy to improve tree height (which showed divergent selection), whereas significant genetic gain for the other traits might be obtained by selection within provenances.