Long distance pollen dispersal and intrapopulation genetic structure determined by clonal diversity in Hymenaea stigonocarpa populations of the Brazilian savanna

Key message Although all populations show extensive pollen immigration, the occurrence of spatial genetic structure and biparental inbreeding decreased genetic diversity and effective population size. The Brazilian savanna is the second largest Neotropical biome, and a globally important biodiversity hotspot. Basic knowledge of the ecology and genetics of its species can help conserve this important biome. We investigated genetic diversity, spatial genetic structure (SGS), pollen dispersal, and mating system in three Hymenaea stigonocarpa populations (AS, PE, IT) in the Brazilian savanna, using microsatellite loci and samples of adult trees from all populations and seeds from the IT population. As a result of the long geographic distance between populations, the genetic differentiation among them was high (0.397). Individuals of the IT population presented a grouped distribution due to root propagation, resulting in low genotypic richness ( GR = 0.194) and allelic richness ( R = 4), and high SGS ( Sp = 0.064) compared to AS and PE ( GR > 0.98, R > 5, Sp