7 research outputs found

    The Adaptation Process Of Ceratitis Capitata To The Laboratory Analysis Of Life-history Traits

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    Colonizing species are believed to have genetic plasticity that permits their adaptation to new habitats. The Mediterranean fruit fly, Ceratitis capitata, is known for this ability, reflected in its present world-wide geographical distribution. To investigate the genetic components of the colonizing capacity of this species, we studied the life-table parameters in (a) a recently-collected wild population, (b) a laboratory strain maintained for 6 years, and (c) a hybrid population resulting from crosses between the wild females and long-term laboratory maintained males. All the strain were collected in the same host and place. Within a few generations, both the hybrid and the wild strains showed life table parameters (egg, larval, pupal and adult mortalities, net reproductive rate, intrinsic rate of population growth, and generation time) similar to those of the laboratory strain. A difference in the speed of adaptation to the laboratory conditions was remarkable, with the hybrid population reaching the values of the long-term laboratory strain much faster than the wild population. An incipient reproductive isolation between the laboratory and the wild population was also observed. The genetic plasticity that allows fast adaptation to new conditions such as those in the laboratory is high in C. capitata, although the genetical variability measured by enzyme electrophoresis in Brazilian populations is low. This suggests that the isozyme variation observed is not related to this kind of adaptation. © 1988 Kluwer Academic Publishers.49319520

    Modelo multicritério aditivo na geração de mapas de suscetibilidade à erosão em área rural

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    O objetivo deste trabalho foi avaliar a geração de um mapa de suscetibilidade à erosão, em área rural, no Município de Guararapes, SP, por meio de modelo multicritério aditivo. Foram utilizados mapas digitais dos temas: relevo (declividade e comprimento das rampas); pedologia (obtida em campo); uso e cobertura das terras da região; e interpretação do modelo digital de elevação. Os mapas digitais foram tratados em ambiente de sistema de informação geográfica, por meio do método multicritério aditivo, e validados pelo modelo da equação universal de perda de solo (USLE). Foram geradas cinco classes de suscetibilidade à erosão: baixa, moderada, alta, muito alta e altíssima. O mapa de risco obtido por multicritério aditivo teve boa correspondência com o modelo USLE. O mapa de suscetibilidade à erosão pode ser aplicado ao planejamento agrícola e ambiental da área rural do Município de Guararapes
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