High and similar genetic diversity in wild and cultivated populations of the economically important fruit tree Caryocar coriaceum Wittm. in Caatinga

Domestication involves a genetic selection process that may lead to loss of genetic diversity. Several species that are used as food resources by native Americans may have been domesticated or managed to some degree. In the Cerrado and the Caatinga ecoregions in Brazil, fruits and seeds are commonly found in archeological sites, implying human consumption. Here, we test the hypotheses that different management systems affect genetic diversity and differentiation, and edible morphological traits of fruits and seeds of Caryocar coriaceum. We analyzed the variation in microsatellite loci and morphological traits in wild populations under extractivism, in situ managed populations and cultivated populations. We found similar genetic diversity, allelic richness and inbreeding in populations in different management systems, contrary to our expectations. We also found no genetic differentiation among management systems, contradicting our prediction. These results suggest that the species has not experienced a bottleneck, most likely because the plantations are a first-generation selection of seeds in wild populations, and the farmers keep high tree density and large planted populations favoring high genetic diversity. This also suggests a management system allowing the maintenance of genetic diversity. However, we found high differences in edible morphometric traits, supporting our prediction. Cultivated and in situ management populations showed larger fruit and seed traits than wild populations under extrativism. These findings suggest that farmers are intentionally selecting fruits with some edible characteristics to establish the plantations or to keep and manage populations in situ.