58 research outputs found

    Projeto ABC Corte: intensificação da produção de carne a pasto no Tocantins: o caso da Fazenda Limeira.

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    Este documento tem por finalidade apresentar os resultados tĂ©cnicos e financeiros obtidos na Unidade de ReferĂȘncia TecnolĂłgica de CristalĂąndia, localizada na Fazenda Limeira, parceira do projeto ABC Corte. Neste trabalho demonstra-se como a aplicação de tecnologias, como manejo rotacionado do pastejo e adubação de pastagens, podem contribuir para o aumento da produtividade e rentabilidade da pecuĂĄria tocantinense. Trabalho semelhante tem sido desenvolvido em diversas outras propriedades rurais no estado. A equipe da Embrapa apresenta nesse documento indicadores do desempenho tĂ©cnico e financeiro de tais tecnologias nas condiçÔes tocantinenses, possibilitando aos bovinocultores uma importante referĂȘncia no processo de intensificação da produção de carne a pasto.bitstream/item/208469/1/CNPASA-2019-doc38.pd

    Chromosomal evidence for a putative cryptic species in the Gymnotus carapo species-complex (Gymnotiformes, Gymnotidae)

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    <p>Abstract</p> <p>Background</p> <p>In this study we examined the karyotypes of morphologically indistinguishable populations of the electric knifefish <it>Gymnotus carapo sensu stricto </it>from the Eastern Amazon of Brazil. These were identified unambiguously on the basis of external morphology, meristics, and pigmentation.</p> <p>Results</p> <p>Specimens from one of five localities exhibited a karyotype previously not documented for <it>Gymnotus </it>species in the Amazon basin: 2n = 40 (34M/SM+6ST/A). Samples from the other four localities exhibited a different karyotype: 2n = 42 (30M/SM+12ST/A), which we had previously described. Specimens from all five localities presented constitutive heterochromatin in the centromeric region of almost all chromosomes, including in the distal and interstitial regions. Staining with 4'6-Diamidino-2-phenylindole revealed C-positive banding. In both karyotypes the Nucleolar Organizer Region (NOR) was located on the short arm of pair 20, and Chromomycin A<sub>3 </sub>stained the NORs. Fluorescent <it>in situ </it>hybridization with telomeric probes showed an Interstitial Telomeric Sequence (ITS) in the proximal short arm of a metacentric pair in the 2n = 40 karyotype.</p> <p>Conclusion</p> <p>The difference between the two karyotypes on the diploid number and chromosome morphology can be explained by rearrangements of the fusion-fission type and also by pericentric inversions. The presence of ITS in a metacentric pair of the 2n = 40 karyotype suggests that the difference in the diploid number of the karyotypes results from a fusion. The consistent 2n = 42 karyotype at four localities suggests an interbreeding population. However, because fusion-fission and pericentric inversions of this nature typically result in reproductive isolation, we speculate that the form with the 2n = 40 karyotype is a different species to that of the 2n = 42 form. Nonetheless, we did not observe evident differences in external morphology, meristics and pigmentation between the two forms, which suggest that they represent cryptic sympatric species in the <it>G. carapo </it>species complex. We speculate that the chromosomal speciation occurred recently, allowing insufficient time for the fixation of other differences following post-zygotic isolation.</p

    Scarabaeoidea (Insecta : Coleoptera) in the Brazilian Cerrado : current state of knowledge

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    Besouros pertencentes Ă  superfamĂ­lia Scarabaeoidea ocupam habitats variados, possuem hĂĄbitos alimentares diversifi cados, desempenham importante papel ecolĂłgico e diversas espĂ©cies apresentam importĂąncia agrĂ­cola. No entanto, estudos com esse grupo na regiĂŁo do Cerrado sĂŁo escassos. Nesta revisĂŁo realizou-se um levantamento dos artigos publicados nos Ășltimos 30 anos a respeito dos Scarabaeoidea no Cerrado. Foram recuperados 64 artigos, realizados em nove unidades da federação, que focavam quatro temas principais espĂ©cies praga, aspectos bioecolĂłgicos, biodiversidade e importĂąncia ecolĂłgica, e tĂ©cnicas e metodologias de coleta de Scarabaeoidea. Os resultados desta revisĂŁo indicam que poucos estudos foram realizados com os Scarabaeoidea no Cerrado brasileiro nas Ășltimas dĂ©cadas frente Ă  importĂąncia e diversidade desse grupo de insetos.Beetles belonging to the superfamily Scarabaeoidea occupy different habitats, present feeding habits diversifi ed, play an important ecological role and several species have agricultural importance. However, studies with this group in the Brazilian Cerrado are scarce. In this review we carried out a survey of scientifi c articles published in the past 30 years concerning Scarabaeoidea in the Cerrado. Were found 64 studies in nine Brazilian states. The studies focused on four main topics: pest species, bioecology, biodiversity and ecological importance, techniques and methodologies for collecting Scarabaeoidea. The results of this review indicate that few studies have been conducted with Scarabaeoidea in the Cerrado in recent decades compared to the importance and diversity of this group of insects

    First report on dung beetles in intra-Amazonian savannahs in Roraima, Brazil

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    This is the first study to address the dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) diversity in intra-Amazonian savannahs in the state of Roraima, Brazil. Our aim was to survey the dung beetle fauna associated with these savannahs (regionally called 'lavrado'), since little is known about the dung beetles from this environment. We conducted three field samples using pitfall traps baited with human dung in savannah areas near the city of Boa Vista during the rainy seasons of 1996, 1997, and 2008. We collected 383 individuals from ten species, wherein six have no previous record in intra-Amazonian savannahs. The most abundant species were Ontherus appendiculatus (Mannerheim, 1829), Canthidium aff. humerale (Germar, 1813), Dichotomius nisus (Olivier, 1789), and Pseudocanthon aff. xanthurus (Blanchard, 1846). We believe that knowing the dung beetles diversity associated with the intra-Amazonian savannahs is ideal for understanding the occurrence and distribution of these organisms in a highly threatened environment, it thus being the first step towards conservation strategy development
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