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

• Autor(a) principal: Fernandes, Mariana Zaniol
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/273
• topic: ZOOLOGIA; ABELHAS; SINECOLOGIA; POLINIZAÇÃO; FLORESTAS; CNPQ::CIENCIAS BIOLOGICAS::ZOOLOGIA

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 isolínea, cause no harm to the bees. Thus, the hypothesis of changes caused by GM pollen consumption is discarded.