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ABSTRACT The aim of this study was to evaluate the genetic diversity and structure in the germoplasm of Oenocarpus mapora conserved at Eastern Amazon. Thus, 88 individuals were genotyped with five microsatellite loci. These individuals belong to 24 accessions that were sampled in eight sample places of three Brazilian Amazon states conserved at the Active Germplasm Bank (AGB) of Embrapa Eastern Amazon. All loci were polymorphic and they generated 85 alleles with an average of 17 alleles per loci. Total genetic diversity (HE) was 0.48. Sample places were considered genetically distinct, with ?p = 0.354. The analysis of molecular variance (AMOVA) identified that the genetic portion among areas was of 36.14% and within 63.86%. The Nei distances varied from 0.091 between Abaetetuba and Santo Antônio do Tauá, both in the state of Pará (PA), to 4.18, between Parintins, AM and Rio Branco, AC. By means of Bayesian analysis, it was identified nine clusters that compose the accessions of the germplasm bank, with different distributions among individuals. The study showed high fixation rates per sample area, which indicates that there may have been significant inbreeding or crossing among parental individuals. It suggests that future samples should be made of different plants in natural populations. Even though, it was verified that there is considerable genetic variation in the germplasm of O. mapora.

A mangueira é uma das principais fruteiras comerciais no Semiárido brasileiro, sendo que a cultivar Tommy Atkins ocupa 85% da área total cultivada com a cultura. O objetivo deste trabalho foi avaliar o emprego de estratégias para reduzir o período juvenil e as trabalhosas polinizações manuais em mangueira, de forma a acelerar o desenvolvimento de novas cultivares da espécie para o Semiárido brasileiro. Foram identificadas plantas isoladas das cultivares Haden e Espada dentro de plantios comerciais da cultivar Tommy Atkins, numa fazenda exportadora de manga, em Petrolina-PE. Mudas das progênies foram transplantadas com seis meses de idade para o campo. O manejo para a indução floral foi realizado com poda, controle da irrigação e aplicação de Paclobutrazol e nitrato de potássio. O DNA extraído das progênies e parentais foi submetido a análises com marcadores microssatélites publicados para Mangifera indica L. O manejo combinado foi eficiente para induzir a floração e a frutificação em, aproximadamente, 70% das progênies após dois anos e meio de transplantio. Dos 94 indivíduos analisados com três microssatélites, 83% foram identificados como híbridos entre 'Haden' x 'T. Atkins'. Dos 401 indivíduos analisados com um microssatélite, 10% foram identificados como híbridos entre 'Espada' x 'T. Atkins'. A estratégia adotada foi eficiente para reduzir o período juvenil e evitar os trabalhosos cruzamentos manuais em mangueira, sendo que o desenvolvimento de novas cultivares da espécie para a região pode ser concluído com oito a dez anos, incluindo as rigorosas avaliações agronômicas.Mango is one of the most important fruit crop in the Brazilian Semi-Arid region. The cultivar Tommy Atkins has been grown in 85% of total area dedicated to this crop. The goal of this research was to evaluate strategies to reduce the juvenile period and to replace the laborious hand pollinization in order to accelerate the development of mango new cultivars to the region. Isolated plants of 'Haden' and 'Espada' were identified within a commercial orchards established with "Tommy Atkins' in a farm dedicated to export mangoes in Petrolina, PE, Brazil. Seedlings with six months old were transplanted to field. Floral and fruit setting were accomplished with pruning, irrigation management, application of paclobutrazol and potassium nitrate. DNA extracted from progenies and parental was analyzed with Mangifera indica published microsatellites. The combined management was efficient to induce flowering and fruit setting in, approximately, 70% of the progenies, after two year and half of field establishment. Among ninety-four individuals analyzed with three microsatellites 83% were identified as true hybrids of 'Haden' x 'T. Atkins'. Among four hundred and one individuals analyzed with only one microsatellite 10% were identified as true hybrids of 'Espada' x 'T. Atkins'. The adopted strategies were efficient to reduce the juvenile period and the laborious hand crossing in mango. It was estimated that the development of new mango cultivars could be accomplished with eight to ten years of work, including the complex agronomic evaluations.

Uma investigação sobre a diversidade genética entre 11 diplóides melhorados de bananeira, por meio de nove características agronômicas e 16 marcadores microssatélites, foi implementada na Embrapa Mandioca e Fruticultura Tropical, Cruz das Almas (BA), Brasil. A distância generalizada de Mahalanobis indicou alto grau de divergência genética. Os genótipos foram agrupados em três grupos. As características altura de planta, número de pencas, número de frutos e diâmetro do pseudocaule contribuíram com grande parte da divergência genética observada. O número de alelos obtidos foi 120, com média de 7,51 alelos por primer. A similaridade genética média foi de 0,44, variando de 0,29 a 0,60. Novas combinações parentais podem ser identificadas com base na divergência entre estes diplóides, contribuindo para o desenvolvimento de novos diplóides melhorados, evitando o estreitamento da base genética e disponibilizando nova variabilidade genética para a seleção.An investigation about the genetical diversity among eleven banana diploid genotypes using nine agronomical characteristics and sixteen microsatellite markers was implanted at Embrapa Cassava and Tropical Fruits, Cruz das Almas (BA), Brazil. The generalized distance of Mahalanobis indicated the presence of genetic diversity. The genotypes were grouped into tree clusters. Among the investigated characteristics, the plant height, number of bunch's, number of fruits per bunch and pseudostem exhibited high contribution towards genetic divergence. The average number of alleles per primer was 7.51, with a total of 120 alleles identified. The average similarity among the all diploid was 0.44, range from 0.29 up to 0.60. New parental combinations can be identified with base of the divergence between these diploids, contributing for development of new improved diploids preventing the narrow genetic base and creating new genetic variability for selection.