Exploring genetic diversity and structure of Acacia senegal (L.) Willd. to improve its conservation in Niger

The genetic diversity of African forest resources is poorly documented while it can be the basis for adapting these resources to climatic variations. This study aimed to characterize the genetic diversity of the Acacia senegal (L.) Willd in its natural range in Niger. 252 individuals from 10 populations of the species, across three gum basins were analyzed with 9 nuclear microsatellite markers. Genetic diversity indexes are high in all the populations studied: number of allele (Na) varies from 4.00 to 5.44; allele richness (R) varies from 3.42 to 4.49; observed heterozygosity (Ho) and expected heterozygosity (He) range from 0.44 to 0.56 and from 0.46 to 0.63, respectively. The values of differentiation index (Fst) per pair of population range from 0.0057 to 0.110 and 20% of these values are not significant indicating a low differentiation between populations. In addition, Molecular Variance Analysis shows that 93% of total variation is within populations. Through Bayesian model, a structure of population into three groups is observed. These results could form the basis for building sustainable management and conservation strategies of genetic resources of A. senegal in Niger. Key words: Genetic diversity, microsatellites, Acacia senegal, climate change, Niger.