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Aim Many tropical tree species have poorly delimited taxonomic boundaries and contain undescribed or cryptic species. We examined the genetic structure of a species complex in the tree genus Carapa in the Neotropics in order to evaluate age, geographic patterns of diversity and evolutionary relationships, and to quantify levels of introgression among currently recognized species. Location Lowland moist forests in the Guiana Shield, the Central and Western Amazon Basin, Chocó and Central America. Methods Genetic structure was analysed using seven nuclear simple sequence repeats (nuSSR), five chloroplast SSRs (cpSSR), and two chloroplast DNA (cpDNA) intergenic sequences (trnH-psbA and trnC-ycf6). Bayesian clustering analysis of the SSR data was used to infer population genetic structure and to assign 324 samples to their most likely genetic cluster. Bayesian coalescence analyses were performed on the two cpDNA markers to estimate evolutionary relationships and divergence times. Results Two genetic clusters (nu_guianensis and nu_surinamensis) were detected, which correspond to the Neotropical species C. guianensis (sensu latu) and C. surinamensis. Fourteen cpDNA haplotypes clustered into six haplogroups distributed between the two nuclear genetic clusters. Divergence between the haplogroups was initiated in the Miocene, with some haplotype structure evolving as recently as the Pleistocene. The absence of complete lineage sorting between the nuclear and chloroplast genomes and the presence of hybrid individuals suggest that interspecific reproductive barriers are incomplete. NuSSR diversity was highest in C. guianensis and, within C. guianensis, cpDNA diversity was highest in the Central and Western Amazon Basin. Regional genetic differentiation was strong but did not conform to an isolation-by-distance process or exhibit a phylogeographical signal. Main conclusions The biogeographical history of Neotropical Carapa appears to have been influenced by events that took place during the Neogene. Our results point to an Amazonian centre of origin and diversification of Neotropical Carapa, with subsequent migration to the Pacific coast of South America and Central America. Gene flow apparently occurs among species, and introgression events are supported by inconsistencies between chloroplast and nuclear lineage sorting. The absence of phylogeographical structure may be a result of the ineffectiveness of geographical barrier

Made available in DSpace on 2013-09-27T14:53:04Z (GMT). No. of bitstreams: 1 WOS000308817800014.pdf: 379718 bytes, checksum: a957238b7822bf2ada55c2c4a88d949f (MD5) Previous issue date: 2012-01-01 Made available in DSpace on 2013-09-30T19:24:50Z (GMT). No. of bitstreams: 1 WOS000308817800014.pdf: 379718 bytes, checksum: a957238b7822bf2ada55c2c4a88d949f (MD5) Previous issue date: 2012-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:34:50Z No. of bitstreams: 1 WOS000308817800014.pdf: 379718 bytes, checksum: a957238b7822bf2ada55c2c4a88d949f (MD5) Made available in DSpace on 2014-05-20T15:34:50Z (GMT). No. of bitstreams: 1 WOS000308817800014.pdf: 379718 bytes, checksum: a957238b7822bf2ada55c2c4a88d949f (MD5) Previous issue date: 2012-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) European Commission (SEEDSOURCE Project) Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) The Neotropical tree Hymenaea courbaril, locally known as Jatoba, is a valuable source of lumber and also produces comestible and medicinal fruit. We characterized Mendelian inheritance, linkage and genotypic disequilibrium at nine microsatellite loci isolated from H. courbaril, in order to determine if they would provide accurate estimates of population genetic parameters of this important Amazon species. The study was made on 250 open-pollinated offspring originated from 14 seed trees. Only one of nine loci presented significant deviation from the expected Mendelian segregation (1: 1). Genotypic disequilibrium between pairwise loci was investigated based on samples from 55 adult and 56 juvenile trees. No genetic linkage between any paired loci was observed. After Bonferroni's corrections for multiple tests, we found no evidence of genotypic disequilibrium between pairs of loci. We conclude that this set of loci can be used for genetic diversity/structure, mating system, gene flow, and parentage analyses in H. courbaril populations. Inst Florestal São Paulo, São Paulo, Brazil Inst Pesquisas Jardim Bot Rio de Janeiro, Inst Pesquisas, Rio de Janeiro, RJ, Brazil Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Amazonia Oriental, Belem, Para, Brazil Univ Estadual São Paulo Julio de Mesquita Filho, Fac Engn Ilha Solteira, Ilha Solteira, SP, Brazil Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Florestas, Curitiba, Parana, Brazil Inst Nacl de Pesquisas da Amazonia, Lab Genet & Biol Reprodut Plantas LARGEN, Manaus, Amazonas, Brazil Univ Estadual São Paulo Julio de Mesquita Filho, Fac Engn Ilha Solteira, Ilha Solteira, SP, Brazil European Commission (SEEDSOURCE Project): 003708 CNPq: 2006/04490-9