Occurrence of zearalenone in wheat- and corn-based products commercialized in the State of Paraná, Brazil

The productivity of wheat and corn crops depends on climatic conditions and resistance against phytopathogenic fungi such as those of the genus Fusarium. Some species of this genus produce zearalenone (ZEA), a mycotoxin with hyperestrogenic effects. The objective of this study was to investigate the presence of ZEA in samples of cracked wheat (n = 109), popcorn (n = 51) and corn grits (n = 50) commercialized in the State of Paraná, Brazil. Commercial samples of each crop were collected between September 2007 and June 2008 and analyzed by thin-layer chromatography. The method used for detection of the mycotoxin in wheat and corn derivatives presented a recovery rate of 94.5% and 99.5%, respectively, detection limit of 40 g.kg-1 and quantification limit of 55 g.kg-1. No contamination with ZEA was detected in cracked wheat samples. Among the corn derivatives, only one cracked corn sample was contaminated with ZEA (64 g.kg-1). Despite the low contamination observed, monitoring the occurrence of mycotoxins in foods is important to ensure safety.(AU)

Spar genetic analysis of two invasive species of Cichla ( Tucunaré )( Perciformes: Cichlidae ) in the Paraná river basin / Análise genética via spar, de duas espécies de Cichla (Tucunaré)(Perciformes: Cichlidae) introduzidas na Bacia do rio Paraná

The introduction of exotic species in lake ecosystems has been greatly highlightedin the literature worldwide. Since introduction may threaten diversity of native fish, the issueturns up to be of paramount importance. Ecological effects may be predation, competition,parasitism or genetic, that is, changes in the genetic pool of populations owing to the occurrenceof hybrids. Although the Tucunaré fish (Cichla) is native to the Amazon region, it can be foundin other hydrographic basins in which it has been introduced. RAPD molecular marker researchshowed that there are two species (Cichla kelberi and C. piquiti) belonging to the genus Cichla inthe rivers of the Paraná basin. Different morphotypes in the region may also be due tohybridization. Current research used SPAR molecular markers to confirm the presence ofhybrids and the rupture of isolation mechanisms. Seventy-two specimens collected in severalsites of the river Paraná and Amazon basins were analyzed. Since exclusive SPAR molecularmarkers were obtained for Cichla kelberi and C. piquiti populations, the introduction of the twospecies in the region has been confirmed. Identification of the markers in specimens of theParaná river basin confirmed hybridization between these exotic species.(AU)

A introdução de espéciesexóticas nos ecossistemas lacustres tem sido muito destacada na literatura mundial, pois ameaça adiversidade de peixes nativos, tornando-se uma questão de extrema importância. Os efeitosobservados podem ser ecológicos, como predação, competição e parasitismo ou genéticos, comoa ocorrência de híbridos. Apesar do peixe tucunaré (Cichla) ser nativo da região amazônica, elepode ser encontrado em outras bacias hidrográficas nas quais foram introduzidos. Estudosutilizando marcadores moleculares RAPD revelaram que existem duas espécies (Cichla kelberi eC. piquiti) do gênero Cichla na bacia do alto rio Paraná e morfotipos diferentes que podem serdevido à hibridização. O presente trabalho utilizou marcadores moleculares SPAR paraconfirmar a presença de híbridos e os mecanismos de ruptura de isolamento entre essas espécies.Setenta e dois espécimes foram coletados em diversos pontos da bacia do rio Paraná e da baciaAmazônica e foram analisados. Marcadores moleculares SPAR exclusivos foram obtidos parapopulações de Cichla kelberi e C. piquiti, confirmando a introdução das duas espécies na região. Aidentificação dos marcadores diagnósticos em espécimes da bacia do rio Paraná confirmoutambém a hibridização entre estas espécies exóticas.(AU)