ABSTRACT. This study uses ISSR molecular markers to characterize the demographic pattern, and spatial genetic structure (SGS) at different life stages of development (cohorts) in a natural population of Copernicia prunifera in the Rio Grande do Norte State, Brazil. All individuals were sampled and georeferenced in a 0.55-ha plot. The demographic analyses showed a clustered pattern in the first-distance classes and a random or segregated pattern at higher distance classes for all cohorts. Among the three studied life stages, juveniles showed the greatest value for Nei's genetic diversity index (H E = 0.369), while the lowest was found among reproductive adults (H E = 0.341). Greater genetic differentiation was found within life stages (98.61%) than among stages (1.39%). The total population (N = 161) showed positive and significant kinship in the first-distance class (12.3 m). The juveniles showed significant kinship up to 10.5 m. Non-reproductive adults had a positive kinship in the first-distance class (11.0 m) and a random distribution of genotypes in the remaining classes, while reproductive adults showed a random spatial distribution of genotypes. Tests for genetic bottleneck showed that the number of loci with excess observed heterozygosity was greater than expected. The SGS results reflected the restricted seed dispersion of the species, and the genetic bottleneck reflected the reduction of genotypes as a result of the anthropization of C. prunifera natural environments.

Fragmentation leads to changes in the size and dynamics of forest populations. Studies of genetic diversity support strategies for preserving the genetic resources, and the data to date for the Atlantic Forest in northeast Brazil is scarce. Thus, the objective of this study was to evaluate the genetic diversity of Protium heptaphyllum (Burseraceae) tree species in three populations. We sampled 64 individuals in this study, for which seven primers used generated 90 loci, with 93% being polymorphic. The average number of alleles was 1.59, the effective number of alleles was 1.34, Nei's genetic diversity was 0.20, and the Shannon index was 0.30. AMOVA indicated higher genetic variation among individuals within populations than among populations. Bayesian analysis revealed the existence of two distinct genetic groups, in which the MAC (Macaíba) population was the most differentiated. Genetic bottleneck tests indicated that all populations presented significant reductions in the population size. In situ conservation strategies must be adequately maintained considering the current isolation of studied populations, the genetic bottleneck, and the low average genetic diversity detected. Also, further recovery of degraded areas in the vicinity and ex situ conservation are recommended.

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Resumo:Objetivou-se neste estudo descrever as características morfológicas dos frutos e das sementes da palmeira Copernicia prunifera em uma população natural, no município de Apodi, Rio Grande do Norte. Foram aferidos o comprimento, o diâmetro e a massa fresca dos frutos e das sementes de 12 indivíduos adultos. Os dados biométricos foram analisados por meio de estatísticas univariadas e os desvios da normalidade dos dados foram confirmados pelo teste de Lilliefors (para K amostras), para uso da correlação não paramétrica de Spearman (r s ). As similaridades das variáveis biométricas entre indivíduos foram observadas em dendrogramas, por meio da matriz de distância euclidiana simples. Em relação à assimetria, ocorreu distribuição à esquerda no comprimento dos frutos e das sementes, apontando maior quantidade de frutos e sementes com menor comprimento. O diâmetro dos frutos e a massa fresca das sementes evidenciaram pouca amplitude na distribuição dos dados (K > 3). De acordo com os dendrogramas de similaridade, observou-se que os indivíduos 4 e 10 apresentaram maior similaridade entre as variáveis biométricas dos frutos. Já os indivíduos 4 e 9 foram os mais similares em relação às variáveis biométricas das sementes. Quanto às correlações entre as variáveis biométricas, detectaram-se poucas correlações significativas, exceto entre o diâmetro e a massa fresca das sementes (r s = 0,7993; P < 0,05). Os resultados obtidos neste estudo são relevantes, pois servirão como base para futuros trabalhos envolvendo melhoramento, propagação e conservação genética da espécie.Palavras-chave: carnaúba; semiárido; caatinga; espécie florestal. Biometric characteristics of the fruits and seeds of the palm Copernicia prunifera (Arecaceae)Abstract: The objective of this study was to describe the morphological characteristics of the fruits and seeds of the palm Copernicia prunifera in a natural population in Apodi municipality, RN, Brazil. The length, the diameter and the fresh mass of the fruits and seeds of 12 adult individuals were measured. Biometric data were analyzed through univariate statistics, and deviations from the normal range of data were confirmed by the Lilliefors test (for K samples), for use of non-parametric Spearman correlation (r s ). The similarities of biometric variables between individuals were observed in dendrograms, through the simple Euclidean distance matrix. In relation to the asymmetry, asymmetrical distribution was seen in the left of the fruits and seeds length, pointing higher amount of fruits and seeds with less length. The diameter of the fruits and the fresh mass of the seeds showed little amplitude in the distribution of data (K > 3). According to the similarity dendrograms, it was observed that the individuals 4 and 10 had more similarity between the biometric variables of fruits. Individuals 4 and 9 were the most similar in relation to biometric variables of seed. As for correlations between biometric variables, few significant correlations were found, except between the diameter and the fresh m...