Fonte de financiamento: projeto PROPALMA-Pesquisa, desenvolvimento e inovação em palmáceas para a produção de óleo e aproveitamento econômico de coprodutos e resíduos-Financiado pela FINEP. Conflito de interesse: Os autores declaram não haver conflito de interesse.

ABSTRACT.We assessed the level and distribution of genetic diversity in three species of the economically important palm genus Astrocaryum located in Pará State, in northern Brazil. Samples were collected in three municipalities for Astrocaryum aculeatum: Belterra, Santarém, and Terra Santa; and in two municipalities for both A. murumuru: Belém and Santo Antônio do Tauá and A. paramaca: Belém and Ananindeua. Eight microsatellite loci amplified well and were used for genetic analysis. The mean number of alleles per locus for A. aculeatum, A. murumuru, and A. paramaca were 2.33, 2.38, and 2.06, respectively. Genetic diversity was similar for the three species, ranging from H E = 0.222 in A. aculeatum to H E = 0.254 in A. murumuru. Both F ST and AMOVA showed that most of the genetic variation was found within populations for all three species, but high genetic differentiation among populations was found for A. aculeatum. Three loci were not in HardyWeinberg equilibrium, with populations of A. paramaca showing a tendency for the excess of heterozygotes (F IS = -0.144). Gene flow was 2 N.P. Oliveira et al. Genetics and Molecular Research 16 (3): gmr16039676 high for populations of A. paramaca (N m = 19.35). Our results suggest that the genetic diversity within populations followed the genetic differentiation among populations due to high gene flow among the population. Greater geographic distances among the three collection sites for A. aculeatum likely hampered gene flow for this species.

RESUMO -O objetivo deste trabalho foi estimar a variabilidade e a divergência genética entre genótipos de tucumanzeiro-do-pará promissores para a produção de frutos por marcadores de RAPD. Foram coletadas amostras de folhas de 29 plantas-matrizes selecionadas no Banco Ativo de Germoplasma da Embrapa Amazônia Oriental, com base na produção de frutos por planta, mas com pronunciadas variações para outras características. As amostras de DNA foram amplificadas por 24 iniciadores RAPD e analisadas por três métodos multivariados, usando a matriz de dissimilaridades genéticas obtidas pelo complemento aritmético do coeficiente de Jaccard. Foram gerados 332 marcadores moleculares que expressaram 98,5% de polimorfismo. Os marcadores RAPD apresentaram poder de discriminação eficiente entre os 29 genótipos avaliados, constatando-se distância genética média entre os genótipos de 51,7%, variando entre 26,9% e 71,5%. A maior média de distância ocorreu entre o genótipo 22 e os demais, com 66,8%. Os genótipos formaram oito e quinze grupos distintos, possivelmente grupos heteróticos, pelos métodos de agrupamentos UPGMA e Tocher, respectivamente. As análises das coordenadas principais confirmaram a alta variabilidade entre os genótipos. Os marcadores moleculares utilizados permitiram a identificação de ampla variabilidade e forte divergência genética entre os genótipos com ausência de duplicatas, o que possibilita a indicação desses materiais para compor programa de melhoramento genético para a produção de frutos. Termos para indexação: Palmeira, Amazônia, polimorfismo, dissimilaridade, análises multivariadas. VARIABILITY AND GENETIC DIVERGENCE AMONG FIBER PALM TREE (Astrocaryum vulgare Mart.) GENOTYPES FOR FRUIT YIELD BY RAPD MARKERSABSTRACT -The objective of this study was to estimate the variability and divergence among fiber palm tree genotypes promising for fruit yield by RAPD markers. Leaf samples from 29 plants, selected in the Active Germplasm Bank from Embrapa Eastern Amazon, were collected based in the fruit yield, but with variations by other characteristics related to production. The samples of these DNA were amplified with 24 primers and analyzed by three multivariate methods using the matrix of genetic dissimilarities obtained by arithmetic complement of the Jaccard index. 332 molecular markers expressing polymorphism of 98.5% were obtained. The RAPD markers presented efficient discriminating power among the 29 evaluated genotypes, determining an average genetic distance among them of 51.7% ranging from 26.9% to 71.5%. The highest mean of distance occurred between genotype 22 and the remaining genotypes, with 66.8%. Eight and fifteen different clusters, possibly heterotic groups were formed by the UPGMA and Tocher methods, respectively. The principal coordinate analyses confirmed the great variability among genotypes. The markers used permitted identification of variability and genetic divergence among genotypes with absence of duplicates, allowing the indication of this material in breeding programs for fruit yield.

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