Growing out of the tropical forests: domestication syndrome of native Mesoamerican trees in Mayan homegardens

摘要

Domestication syndrome of several plants includes the gigantism of vegetative and reproductive structures. In the Peninsula of Yucatan, species from native forests are found as structural trees in homegardens. This work aimed to evaluate the variability in vegetative and reproductive structures, as well as the genetic diversity of Brosimum alicastrum Sw., Cordia dodecandra A. DC., and Spondias purpurea L. For this purpose, samples of leaves, flowers, and fruits were taken from 20 adult individuals growing in forest and homegarden population of two regions of Yucatan, Mexico. Individuals growing in the homegarden, compared to those that grow in the forest have larger foliar area and higher volume of inflorescence in B. alicastrum and of the flower in C. dodecandra; and greater foliar area and fruit weight in S. purpurea. Based on DNA ISSRs molecular markers, in homegardens, a higher percentage of polymorphic loci and a similar Shannon's diversity index were found compared to the forest in all species. Through a Bayesian assignation, differences in the prevalence of the groups (K = 3) identified per species were found between the forest and homegarden populations of each region. A discriminant analysis, suggests that the probability belonging to the specific genetic group was associated with those of having greater foliar area and volume of inflorescence in B. alicastrum, a larger volume of the flower in C. dodecandra, and higher foliar area and fruit weight in S. purpurea. In conclusion, larger vegetative and reproductive structures associated with particular genotypes may account for a domestication syndrome in multipurpose trees growing in Mayan homegardens.