Morphological characteristics of pequi fruits (Caryocar brasiliense) allows us to obtain information for the conservation, breeding, and detect genetic variability. Thus, the aims of this research were to characterize the genetic diversity of Caryocar brasiliense that produce fruits with and without thorn at the endocarp; determine the important characters in the study of genetic diversity, and to estimate phenotypic and genotypic correlations. 80 fruits with thorns and 90 fruits without thorns were evaluated. Data were used for analysis: Euclidian distance as a measure of dissimilarity and the Tocher method for delimitation of groups; Principal Component Analysis, and genotypic and phenotypic correlations. Genetic dissimilarity of C. brasiliense ranged from 0.066 (B6-D6) to 0.908 (A14-B3). Tocher method allowed dividing the matrices into three groups, the dendrogram into five groups, and the principal components allowed the distribution in 8 groups. We observed 15 significant correlations for characters of fruit with thorns and 31 correlations for characters of fruit without thorns. The weight of the fruit (with thorns) and the pyrene yield (without thorns) are relevant correlations for production. The groupings generated allowed the classification of the matrices into distinct sets. Allowed the identification of potential producers plants that could be used in breeding programs.

The aim of this research was to evaluate genetic diversity among genotypes of “pequi”, Caryocar brasiliense, producing fruits with and without thorns in the endocarp, which is one the biometric characteristics of the fruits. The variance components associated with the effects of the model and estimates of the proportions of the total phenotypic variation were estimated due to the difference between groups, the difference between genotypes within each group, the difference between fruits within genotypes and within of groups. The genetic diversity within each group was verified, mainly in the group of plants producing fruit without thorns. In this study, H² varied from 0.0 to 88.40% in the group of fruits with thorns and from 0.0 to 96.32% in the group of fruits without thorns. Biometric evaluations demonstrate that the genotypes studied presented statistically significant differences; which shows that the population has a high genetic potential for germplasm conservation and breeding.

Apomictic populations, which produce seeds with embryos without proper sexual syngamy, often show low genetic diversity, but eventually, such diversity has been reported to be surprisingly high. We studied here the genetic diversity in agamic complexes of Eriotheca crenulata (comb. n. E. gracilipes), E. pubescens (Malvaceae-Bombacoideae), and Handroanthus ochraceus (Bignoniaceae), tropical tree species from the savannas in Central Brazil. We evaluated the genetic diversity and structure of self-fertile polyploid sporophytic apomicts versus self-sterile diploid or tetraploid sexual populations by using dominant ISSR markers. Genetic diversity was either similar or even higher in apomictic populations of E. crenulata and E. pubescens, but the opposite was observed in some populations of H. ochraceus. Only two individuals of E. pubescens showed identical ISSR profiles, so strict clonality in adult individuals was very rare among the studied trees. The genetic variability was notably higher within populations than among populations of H. ochraceus and very similar among and within populations of Eriotheca species. Ordination, clustering, and Bayesian analyses showed a clear distinction between populations of Eriotheca species with different breeding systems. But for H. ochraceus, a sexual population was actually grouped with the apomictics. As in other studies, eventual sexual and recombination events seem to increase genetic diversity in apomictic populations. This may explain the similar genetic diversity among apomictic and sexual populations in the studied agamic complexes and the virtual absence of strict clonal individuals. The results have evolutionary and ecological consequences for the threatened Neotropical savanna trees.