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Efeito do p?len de eucalipto geneticamente modificado em abelhas Scaptotrigona bipunctata (MELIPONINI) e Apis mellifera (APINI)

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Previous issue date: 2014-02-18 / Flowering mass of eucalypts trees are attractive to the bees for collection of floral resources, mainly pollen and nectar. The worldwide distribution of Eucalyptus species and the novel generation of genetically modified trees all over the world, especially in Brazil and USA, emphasize the need of information concerning environmental risks, including potential effects on bees. Since the transgenic events are expressed as proteins, the pollen becomes the main route of exposure of transgenic proteins to the bees. The present study aimed to assess the effects of ingestion of pollen from forest areas with genetically modified (GM) eucalypt trees on development of Apis mellifera and Scaptotrigona bipunctata. For this, we assessed the synchronism on development of Apis mellifera, the morphometry of A. mellifera and S. bipunctata on pupal phase and the weight of S. bipunctata immatures. Trials with A. mellifera: in February and March 2011, the study was carried out in an experimental area with GM eucalypt and in a commercial area with conventional trees, without GM eucalypt. A. mellifera colonies were placed in triplicates in the center of experimental area, 400 m, 1.000 m and 85 Km away from area. Brood combs were harvested and the pupae were assessed regarding to the developmental stage, head width (HW) and intertegular distance (ID). Trials with S. bipunctata: under controlled conditions, micro colonies of S. bipunctata were subjected to feeding with GM and non-GM eucalypt pollen. The pollen was obtained from pollen collectors placed in three colonies of A. mellifera established in the experimental area and three colonies in the commercial area. We collected from 10 to 15 pupae/comb, which the weight, HW and ID measurements were obtained. In A. mellifera was verified similarity in proportions of the different developmental stages in all areas. We infer regularity of queens laying of A. mellifera on period, because the spatial-temporal pattern of laying occurred as expected. Regarding to morphometric analysis, differences were observed. The ID mean of pupae from 1.000 m differed from the ID mean found for pupae from colonies in the experimental area and 85 Km away. Differences were also observed in pupae from hives from 400m and 85 Km away. We consider the differences showed as expected, because A. mellifera represent hybrid populations in Brazil, with phenotypic expression among the individuals. Since the differences verified are not progressively related to the distance from the experimental area, the hypothesis of changes caused by ingestion of GM pollen is discarded. Regarding to the morphometric characteristics obtained for S. bipunctata, differences were observed. Nevertheless, the variation coefficient for all micro colonies was lower than 10%, indicating homogeneous groups. Therefore, these differences may be due to of the genetic variation among the populations. The weight analysis of S. bipunctata pupae indicated similarity, which showed a mean of 0.0212 g (SD+-0.0028 g) when fed with GM eucalypt pollen and 0.0204 g (SD+-0.0019 g) when fed with non-GM eucalypt pollen. According to the results, the similarity found in the weight of pupae fed under both treatments suggest that the effect of GM pollen was similar to its non-GM isol?nea, cause no harm to the bees. Thus, the hypothesis of changes caused by GM pollen consumption is discarded. / As flora??es em massa das ?rvores de eucalipto s?o atrativas ?s abelhas para a coleta de recursos florais, principalmente n?ctar e p?len. O amplo espectro geogr?fico de esp?cies de Eucalyptus e a recente gera??o de ?rvores geneticamente modificadas no mundo, especialmente no Brasil e EUA, enfatiza a necessidade de informa??es sobre os riscos ambientais, incluindo potenciais efeitos ?s abelhas. Uma vez que os eventos transg?nicos s?o expressos sob a forma de prote?nas, o p?len torna-se a principal via de exposi??o de prote?nas transg?nicas ?s abelhas. O presente estudo objetiva avaliar os efeitos da ingest?o de p?len proveniente de ?reas florestais com ?rvores de eucalipto geneticamente modificado (GM) no desenvolvimento de Apis mellifera e Scaptotrigona bipunctata. Para tanto, avaliou-se o sincronismo no desenvolvimento de Apis mellifera, a morfometria de A. mellifera e S. bipunctata em est?gio pupal e a massa corporal de imaturos de S. bipunctata. Experimento com A. mellifera: em fevereiro e mar?o de 2011, o estudo foi conduzido em um horto experimental com eucalipto GM e em horto comercial com ?rvores convencionais, livre de eucalipto GM. Colmeias de A. mellifera foram colocadas em triplicatas no centro do horto experimental, e a 400 m, 1.000 m e 85 Km. Favos de cria foram coletados e as pupas foram avaliadas quanto ao est?gio do desenvolvimento, largura da cabe?a (LC) e dist?ncia intertegular (DI). Experimento com S. bipunctata: em laborat?rio, minicol?nias de S. bipunctata (n=6) foram submetidas a alimenta??o com p?len de eucalipto GM e com p?len de eucalipto n?o-GM. O p?len foi obtido a partir de coletores de p?len instalados em tr?s colmeias de A. mellifera instaladas no horto experimental e tr?s colmeias no horto comercial. Foram coletadas de 10 a 15 pupas/ favo, das quais foram obtidos o massa corporal e as medidas da LC e DI. Para A. mellifera, verificou-se similaridade nas propor??es dos distintos est?gios de desenvolvimento em todas as ?reas. Infere-se regularidade da postura das rainhas de A. mellifera no per?odo, pois o padr?o espacial-temporal da postura ocorreu conforme o esperado. Com rela??o as an?lises morfometricas, diferen?as foram observadas. A m?dia da DI das pupas localizadas a 1.000 m diferiu do valor encontrado para pupas das colmeias localizadas no horto experimental e a 85 km. Diferen?as tamb?m foram observadas em pupas de colmeias localizadas a 400 m e 85 km. Consideram-se previstas as diferen?as evidenciadas, pois A. mellifera representa popula??es hibridas no Brasil, com express?o fenot?pica entre indiv?duos. Como as diferen?as verificadas n?o est?o progressivamente relacionadas ? dist?ncia da ?rea experimental, descarta-se a hip?tese de altera??es ocasionadas por ingest?o de p?len GM. No que refere-se ?s caracter?sticas morfometricas obtidas para S. bipunctata, diferen?as foram observadas. No entanto, o coeficiente de varia??o para todas as minicol?nias foi menor que 10%, indicando grupos homog?neos. Portanto tais diferen?as podem ser reflexo da varia??o gen?tica entre as distintas popula??es. As an?lises da massa corporal das pupas de S. bipunctata, indicou semelhan?a, as quais apresentaram em m?dia 0,0212 g (SD+-0,0028 g) quando alimentadas com p?len de eucalipto GM e 0,0204 g (SD+-0, 0019 g) quando alimentadas com p?len de eucalipto n?o-GM. De acordo com o resultado, a semelhan?a encontrada na massa corporal das pupas alimentadas com ambos os tratamentos sugere que o efeito do p?len GM manteve-se semelhante a sua isol?nea n?o-GM, n?o acarretando preju?zo ?s abelhas. Desta forma descarta-se a hip?tese de altera??es ocasionadas por consumo de p?len GM.

Identiferoai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/273
Date18 February 2014
CreatorsFernandes, Mariana Zaniol
ContributorsBlochtein, Betina
PublisherPontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Zoologia, PUCRS, BR, Faculdade de Bioci?ncias
Source SetsIBICT Brazilian ETDs
LanguagePortuguese
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis
Formatapplication/pdf
Sourcereponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS
Rightsinfo:eu-repo/semantics/openAccess
Relation2008925231902741151, 500, 600, 36528317262667714

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