Biomonitoring of water genotoxicity in a Conservation Unit in the Sinos River Basin, Southern Brazil, using the <italic>Tradescantia</italic>micronucleus bioassay

The Tradescantia micronucleus (Trad-MCN) bioassay was used to investigate genotoxicity of water bodies in the Parque Municipal Henrique Luís Roessler (PMHLR), a conservation unit in the city of Novo Hamburgo, Southern Brazil, from November 2010 to October 2011. Every month, cuttings with young inflorescences of Tradescantia pallida var. purpurea were exposed for 24 hours to water collected at three sites in the park: (S1) head of the main stream; (S2) head of a secondary stream; (S3) a point past the junction of the two water bodies in which S1 and S2 were located. As a negative control, cuttings were exposed to distilled water for 24 h every quarter. Micronuclei (MCN) frequency was determined in young tetrads of pollen mother cells and described as MCN/100 tetrads. Rainfall data were also recorded. In nine months at S1 and S2, and in eleven months at S3, micronuclei frequencies were significantly higher than in quarterly controls, in which frequencies varied from 1.19 to 1.62.During sampling, no significant differences were found in MCN frequencies at S1, which ranged from 2.2 to 3.6. At the other sampling sites, there were significant differences between the months evaluated, and MCN frequencies ranged from 1.3 to 6.5 at S2 and from 2.3 to 5.2 at S3. There were no associations between rainfall and MCN frequencies at the three sampling sites. Tradescantia pallida var. purpureaconfirmed genotoxicity in the water bodies of the PMHLR, even at the head of the streams, which suggests that actions should be promoted to control anthropogenic effects in the streams of this conservation unit.</p

In vitro propagation and germplasm conservation of wild orchids from South America

Orchids are an important part of plant biodiversity on this planet due to their high variability among species and their habitats. South America represents more than thirty percent of all known orchid species, Colombia, Ecuador, Brazil, Peru, and Bolivia being among the richest countries in the world in terms of orchid biodiversity. Nevertheless, concerning the orchid conservation status, in Colombia precisely orchids occupy the unlucky first place as the plant family with the highest number of threatened species. There is a similar situation in the rest of the South American countries. The two main threats to orchid survival are both anthropogenic: the first one is deforestation, and the second largest threat to orchids is collection from the wild. One desirable action to safeguard these endangered species is to develop procedures that make possible their massive propagation, which would provide material for both environmental restoration and commercial purposes avoiding extractions from nature. Likewise, the development of systems that allow the ex situ conservation of orchid germplasm is imperative. This chapter reviews the progresses of different in vitro approaches for orchid propagation and germplasm conservation, safeguarding the genetic biodiversity of these species. Several study cases are presented and described to exemplify the protocols developed in the Botanical Institute of Northeast (UNNE-CONICET) for propagating and long-term storing the germplasm of wild orchids from Argentina (Cattleya lundii, Cohniella cepula, C. jonesiana, Gomesa bifolia, Aa achalensis, Cyrtopodium brandonianum, C. hatschbachii, Habenaria bractescens). Moreover, it has been attempted to put together most of the available literature on in vitro propagation and germplasm conservation for South American orchids using different explants and procedures. There are researches of good scientific quality that even cover critical insights into the physiology and factors affecting growth and development as well as storage of several orchid materials. Moreover, studies are still necessary to cover a major number of South American species as well as the use of selected material (clonal) for both propagation and conservation approaches.Fil: Dolce, Natalia Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Medina, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Terada, Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: González Arnao, María Teresa. Universidad Veracruzana; MéxicoFil: Flachsland, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin