Mating system and intrapopulational genetic diversity of Copernicia prunifera (Arecaceae): a native palm from Brazilian semiarid.

The aim of this study was to investigate the mating system and genetic diversity of the palm Copernicia prunifera using inter-simple sequence repeat markers. We found that the C. prunifera has multiple inflorescences with hermaphroditic flowers and pollen viability of 62%. Outcrossing rates at the population level (N = 267) produced a multilocus outcrossing rate (t) of 0.878 and a single-locus outcrossing rate (t) of 0.738, indicating that C. prunifera has a mixed mating system that is preferentially allogamous. The rate of mating among relatives (t - t) was low, indicating limited outcrossing between closely related individuals. The fixation index between seed trees (F) was negative (0.200), suggesting an absence of inbreeding, while the correlation of selfing (r) was high (0.914). The values of the diversity indices among adults and progenies did not differ statistically (H = 0.319 and I = 0.470; H = 0.337 and I = 0.505, respectively). In testing for the presence of genetic bottlenecks using the infinite allele model and the stepwise mutation model, we observed a reduction in the effective population, as well as a deficit in heterozygosity (P < 0.0001). The results of this study inform management strategies for the conservation and genetic improvement of the C. prunifera palm.