The genotoxicity of untreated and treated sewage from two municipal wastewater treatment plants (WTP BN and WTP SJN) in the municipality of Porto Alegre, in the southern Brazilian state of Rio Grande do Sul, was evaluated over a one-year period using the Tradescantia pallida var. purpurea (Trad-MCN) bioassay. Inflorescences of T. pallida var. purpurea were exposed to sewage samples in February (summer), April (autumn), July (winter) and October (spring) 2009, and the micronuclei (MCN) frequencies were estimated in each period. The high genotoxicity of untreated sewage from WTP BN in February and April was not observed in treated sewage, indicating the efficiency of treatment at this WTP. However, untreated and treated sewage samples from WTP SJN had high MCN frequencies, except in October, when rainfall may have been responsible for reducing these frequencies at both WTPs. Physicochemical analyses of sewage from both WTPs indicated elevated concentrations of organic matter that were higher at WTP SJN than at WTP BN. Chromium was detected in untreated and treated sewage from WTP SJN, but not in treated sewage from WTP BN. Lead was found in all untreated sewage samples from WTP SJN, but only in the summer and autumn at WTP BN. These results indicate that the short-term Trad-MCN genotoxicity assay may be useful for regular monitoring of municipal WTPs.

Cattleya intermedia is an Atlantic Forest species endemic to Brazil that is classed as vulnerable on the list of threatened species. In this study, C. intermedia plantlets were micropropagated in an asymbiotic culture and the influence of different concentrations of sucrose (15, 30, 45 and 60 g L -1 , plus a zero sucrose medium) and macronutrient salts (complete Murashige and Skoog (MS) medium and half MS medium (with half-strength macronutrients)) on survival and development of the plantlets was evaluated. In all treatments 100% plantlet survival was achieved. The integrated analysis of height of aerial part, number of leaves per plantlet, fresh mass, number of roots per plantlet and length of the longest root showed that the plantlets exhibited greatest development at the half-strength macronutrient concentrations with 45 or 60 g L -1 of sucrose, as well as at the complete macronutrient concentration with 60 g L -1 of sucrose. Plantlets acclimatized and reintroduced to an environment in which the species occurs naturally exhibited 98.6% survival. The results obtained in this study allowed the establishment of optimal conditions for asymbiotic micropropagation, which is a requisite for future studies focused on conservation of C. intermedia.

A cultura in vitro é uma ferramenta eficiente para a propagação de plantas de importância ecológica e econômica e permite o entendimento acerca de aspectos ecofisiológicos das espécies. Este estudo teve por objetivo avaliar a influência de diferentes concentrações de macronutrientes sobre o desenvolvimento in vitro e a sobrevivência ex vitro de plântulas de Vriesea incurvata, visando à conservação desta bromélia epifítica endêmica da Floresta Atlântica. A germinação in vitro foi avaliada aos 60 dias e as plântulas foram cultivadas por 180 dias em meio MS com 25 ou 50% dos macronutrientes, 25 ou 50% dos sais nitrogenados, bem como com 100% da formulação original do meio. As sementes apresentaram 95% de germinação. Em todos os tratamentos, houve 100% de sobrevivência das plântulas cultivadas in vitro. A redução de todos os macronutrientes ou dos sais nitrogenados mostrou-se benéfica, proporcionando maior comprimento da parte aérea e da raiz maior, maior número de folhas e de raízes, bem como maior massa fresca, além de ter propiciado 97% de sobrevivência das plântulas aclimatizadas ex vitro. Os dados obtidos permitem o estabelecimento de um protocolo de propagação in vitro de V. incurvata, com o objetivo de sua futura reintrodução no habitat natural. Palavras-chave: bromélias, conservação, micropropagação, nutrição mineral. AbstractIn vitro culture is an efficient tool for the propagation of plants of ecological and economic importance and allows the understanding about ecophysiological aspects of the species. The objective of this study was to assess the influence of different macronutrient concentrations on in vitro development and ex vitro survival of Vriesea incurvata plantlets, aiming the conservation of this endemic epiphytic bromeliad from the Atlantic Forest. The in vitro germination was assessed at 60 days and the plantlets were cultivated for 180 days on MS medium with 25 or 50% of the macronutrients, 25 or 50% of the nitrogen salts, or with 100% of the original formulation of the medium. The seeds showed 95% germination. In all treatments, there was 100% survival of in vitro cultivated plantlets. The reduction of all macronutrients or of the nitrogen salts was beneficial, and permitted a greater length of the aerial part and of the major root, a higher number of leaves and roots, and more fresh mass, as well as allowed 97% survival of ex vitro acclimatized plantlets. The obtained data allow the establishment of a protocol for in vitro propagation of V. incurvata, aiming its future reintroduction into the natural habitat.

Biotic and abiotic factors, such as luminosity, temperature, air humidity, and herbivory, can affect the establishment of reintroduced plants in natural habitats. This study evaluated the effects of these factors on the survival and growth of Cattleya intermedia plants reintroduced into a forest fragment in South Brazil. Plants of C. intermedia were obtained from in vitro seed germination in asymbiotic culture. Eighty-eight plants were reintroduced at both the forest edge and forest interior. Plants with greater shoot heights and number of leaves and pseudobulbs suffered more damage from herbivores at the edge. There were no significant differences in morphometric parameters between damaged and non-damaged plants in the interior. Tenthecoris bicolor, Helionothrips errans, Ithomiola nepos, Molomea magna and Coleoptera larvae damaged C. intermedia. Luminosity was higher at the edge, while air humidity and temperature were the same in both environments. Herbivory associated with abiotic factors increased plant mortality in the interior, while abiotic factors were determinative of plant survival at the edge. Luminosity is important to the survival of reintroduced epiphytic orchids, and herbivory affects the success of reintroduction.

Tradescantia pallida var. purpurea cuttings with flower buds are utilized in bioassays to diagnose genotoxic effects of water. The literature describes different substances used to adapt and recover the cuttings before and after exposure to water samples and also describes the effects of different exposure times. This study evaluated and compared the micronuclei (MCN) frequencies in T. pallida when cuttings with flower buds were submitted to different methodological conditions. The bioassay was then applied bimonthly during seven months to assess the genotoxic potential of a site located on the Sinos River in Campo Bom, Rio Grande do Sul, Brazil. Micronuclei frequencies in buds of cuttings adapted and recovered in distilled water and in Hoagland solution were 3.0 and 2.9, respectively, for cuttings exposed to river water, and 1.19 and 1.23 in controls. No significant differences among MCN frequencies were observed when cuttings were exposed for 8, 24 or 32 hours to river water (from 3.07 to 4.73) and in controls (from 1.13 to 2.00) in all samplings during a year. Adaptation and recovery of cuttings in distilled water or Hoagland solution and exposure for different times did not influence the response of T. pallida, indicating that all the conditions tested are viable for biomonitoring of water genotoxicity. Water samples from the Sinos River presented genotoxicity during the period monitored, evidenced by the MCN frequencies recorded which were significantly higher than the frequencies of the controls.

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. purpurea confirmed 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. Keywords

Vriesea incurvata is an epiphytic bromeliad of the Atlantic Forest with ornamental attributes that encourage extractivism. This study assessed the influence of sucrose (10, 30 and 60 g L -1 ) on the survival and development of V. incurvata plantlets cultivated for 180 days on MS medium and acclimatizated for 150 days under controlled conditions. Survival of 100% was recorded in all in vitro treatments. Sucrose at concentration of 60 g L -1 provided highest length of the aerial portion and of the longest root, greatest number of leaves and roots, highest fresh mass and lowest contents of chlorophylls and carotenoids. The higher sucrose concentration also positively influenced the development of plantlets ex vitro, allowing for increased averages for the parameters assessed. The results indicate micropropagation as an alternative by which V. incurvata plantlets may be provided for commercial means, reducing the extractivism from natural populations, or for reintroduction into their natural habitat.RESUMO -Propagação in vitro de Vriesea incurvata: conservação de uma bromélia endêmica da Floresta Atlântica. Vriesea incurvata é uma bromélia epifítica da Floresta Atlântica, com atributos ornamentais que estimulam o extrativismo. Este estudo avaliou a influência da sacarose (10, 30 e 60 g L -1 ) na sobrevivência e no desenvolvimento de plântulas de V. incurvata cultivadas por 180 dias em meio MS e aclimatizadas por 150 dias sob condições controladas. Sobrevivência de 100% foi observada em todos os tratamentos in vitro. Sacarose na concentração de 60 g L -1 propiciou maior comprimento da porção aérea e da raiz mais longa, maior número de folhas e raízes, maior massa fresca e conteúdos menores de clorofilas e carotenoides. A maior concentração de sacarose também influenciou positivamente o desenvolvimento das plântulas ex vitro, permitindo maiores médias para os parâmetros avaliados. Os resultados indicam a micropropagação como alternativa para a obtenção de plântulas de V. incurvata para fins comerciais, reduzindo o extrativismo de populações naturais, ou para reintrodução em habitat natural.Palavras-chave: clorofila, fonte de carbono, micropropagação, nutrição

Anathallis adenochila is a small epiphytic orchid, endemic to the Atlantic Forest in the southern and southeastern regions of Brazil. Information on the species is scarce and limited to distribution and occurrence data, with no reports about its development. In the present study, plantlets were propagated in vitro, and the influence of different concentrations of macronutrient salts and sucrose on the survival and development of the species was assessed. The analysis were performed on complete Murashige and Skoog (MS) medium and half MS medium (with half-strength macronutrients) containing 10, 30 or 60 g L -1 of sucrose. Plantlet survival, height of the aerial part, and the length of the longest root were significantly greater on half MS medium containing 30 or 60 g L -1 of sucrose. The number of leaves per plantlet was higher in the presence of 60 g L -1 of sucrose, regardless of macronutrient concentration, and the highest number of roots was observed in plantlets cultured on half MS medium with 60 g L -1 of sucrose. This first report of Anathallis adenochila in vitro propagation may contribute to future studies on the physiological and ecological aspects of the life cycle of this species.