AZEVEDO, V. C. R.

MARTINS, K.

SOLFERINI, V.

SUJII, P.

WADT, L.

English

Repository Open Access to Scientific Information from Embrapa

POSTER PRESENTATION Open AccessGenetic diversity of Bertholletia excelsa, anAmazonian species of wide distributionPatrícia Sujii1, Karina Martins2, Lucia Wadt3, Vânia Azevedo4*, Vera Solferini1From IUFRO Tree Biotechnology Conference 2011: From Genomes to Integration and DeliveryArraial d’Ajuda, Bahia, Brazil. 26 June - 2 July 2011BackgroundAmazonian upland forests are expansive and can com-prise large continuous tracts. There have been severalstudies on the population genetic structure of species inthis kind of forest, but there are few studies that aim tounderstand genetic structure throughout the Amazon[1]. The Brazil-nut tree, Bertholletia excelsa, is a mono-typic genus, endemic to upland forests and distributedalong almost the entire expanse of the Amazon [2-5].Genetic diversity distribution through Amazon forestis an understudied issue, specially in plants. Quantifyingand understanding population genetic structure, asso-ciated to gene flow and mating system studies are recog-nized as important tools for the development ofstrategies for conservation and management. Such infor-mation can also be helpful in identifying effects of habi-tat fragmentation [6,7].This study aimed to evaluate genetic structure of B.excelsa populations in the Amazon and to verify if thestructuring is influenced by distance between them.MethodsSeven polymorphic microsatellite markers were devel-oped from a dinucleotide-enriched genomic library.Material from 379 individuals was collected from nineAmazonian subpopulations distributed in five Brazilianstates (AC: Acre, AM: Amazonas, AP: Amapá, PA: Pará,RR: Roraima). All seven microsatellite markers devel-oped for the species were used with four others pre-viously published markers [8], for genotyping.Analyses within and among populations were per-formed to evaluate genetic diversity and populationstructure. All nine populations were characterized with11 microsatellite loci for number of alleles per locus,allele frequency and observed and expected heterozygos-ity under Hardy-Weinberg expectation. Wright fixationindices were also estimated. Genetic distance estimateswere correlated with different potential factors to findpossible causes of genetic structure.Results and conclusionsA few alleles were found in each subpopulation andconsiderable variation was observed in alleles found ineach subpopulation and in their allele frequencies, espe-cially when compared with very distant subpopulations.Heterozygote excess was observed in five subpopulationswhile in the other four subpopulations, estimates of FIS,non-significantly different from zero, were found. Theobserved high heterozygote proportions in most subpo-pulations and absence of inbreeding support the exis-tence of self-incompatibility mechanisms and selectionin favor of heterozygotes. Maintenance of genetic varia-bility is favored by the alogamous breeding system,which is an important feature to be considered in con-servation and management strategies, in order to avoidfertility deficits.Fine-scale structure, when present, was small. Esti-mates of inter population genetic structure varied fromlow (q= 0,02) to high (q= 0,244). B. excelsa geneticstructure can be analyzed on three different scales: (i)within population; (ii) among moderately distant popu-lations (<500km); and (iii) among very distant subpopu-lations. At all scales, significant correlations were foundbetween genetic structure and geographic distancebetween pairs of individuals or populations. This mayindicate that distance is an important factor in thispopulation’s genetic structure, but probably there areother factors acting in conjunction, especially on a largegeographical scale.* Correspondence: vania.azevedo@cenargen.embrapa.br4Laboratório de Genética Vegetal, Embrapa Recursos Genéticos eBiotecnologia, Brazilia, BrazilFull list of author information is available at the end of the articleSujii et al. BMC Proceedings 2011, 5(Suppl 7):P5http://www.biomedcentral.com/1753-6561/5/S7/P5© 2011 Sujii et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative CommonsAttribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction inany medium, provided the original work is properly cited.Author details1Laboratório de Diversidade Genética, Universidade Estadual de Campinas,Campinas, Brazil. 2Universidade Federal de São Carlos, Brazil. 3Embrapa Acre,Brazil. 4Laboratório de Genética Vegetal, Embrapa Recursos Genéticos eBiotecnologia, Brazilia, Brazil.Published: 13 September 2011References1. Sampaio AJ: A flora amazônica. Revista Brazileira de Geografia 1942,4(2):57-72.2. Maués MM: Reprodutive phenology and pollination of the Brazil nut tree(Bertholletia excelsa Humb. & Bonpl., Lecythidaceae) in EasternAmazonia. In Pollinating Bees The Conservation Link Between Agriculture andNature - Ministry of Environment / Brazilia P. KEVAN & V.L. Imperatriz Fonseca2002, 245-254.3. Mori SA, Prance GT: Taxonomy, ecology and economic botany of theBrazil nut (Bertholletia excelsa Humb. & Bonpl. Lecythidaceae). Advancesin Economic Botany 1990, 8:130-150.4. Moritz A: Estudos biológicos da floração e frutificação da castanha-do-Brazil. DocumentosEmbrapa/Cpatu, Belém 1984, 29:1-78.5. Salomão R: Densidade, estrutura e distribuição espacial de castanheira-do-Brazil (Bertholletia excelsa H. & B.) em dois platôs de florestaombrófila densa na Amazônia setentrional Brazileira. Boletim do MuseuParaense Emílio Goeldi 2009, 4:11-25.6. Azevedo VCR, Kanashiro M, Ciampi AY, Grattapaglia : Genetic structure andmating system of Manilkara huberi (Ducke) A. Chev., a heavily loggedAmazonian timber species. Journal of Heredity 2007, 98:646-654.7. Erickson DL, Hamrick JL, Kochert GD: Ecological determinants of geneticdiversity in an expanding population of the shrub Myrica cerifera.Molecular Ecology 2004, 13:1655-1664.8. Reis AMM, Braga AC, Lemes MM, Gribel R, Collevatti RG: Development andcharacterization of microsatellite markers for the Brazil nut treeBertholletia excels Humb & Bonpl. (Lecythidaceae). Molecular EcologyResources 2009, 9:920-923.doi:10.1186/1753-6561-5-S7-P5Cite this article as: Sujii et al.: Genetic diversity of Bertholletia excelsa, anAmazonian species of wide distribution. BMC Proceedings 2011 5(Suppl7):P5.Submit your next manuscript to BioMed Centraland take full advantage of: • Convenient online submission• Thorough peer review• No space constraints or color figure charges• Immediate publication on acceptance• Inclusion in PubMed, CAS, Scopus and Google Scholar• Research which is freely available for redistributionSubmit your manuscript at www.biomedcentral.com/submitSujii et al. BMC Proceedings 2011, 5(Suppl 7):P5http://www.biomedcentral.com/1753-6561/5/S7/P5Page 2 of 2

Genetic diversity of Bertholletia excelsa, an Amazonian species of wide distribution.

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Genetic diversity of Bertholletia excelsa, an Amazonian species of wide distribution.

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