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.

Abstract Bromeliaceae is restricted to the Neotropical region and has a high degree of endemism, which contributes to increased biodiversity because of the diverse morphological characteristics of individuals. In order to develop an in vitro conservation technology to obtain plants for reintroduction, seeds of Vriesea flammea L.B.Sm. were collected, sterilized and germinated in culture medium. The plants obtained were cultured for 180 days in MS medium with different concentrations of mineral nutrients (25 and 50% of nitrogenous salts and macronutrients), and different concentrations of sucrose (20, 30, 40, 50 and 60 g L-1), and then acclimatized for 150 days on commercial substrate. When seeds were sterilized directly, only 4% of them were contaminated, whereas sterilization of capsules resulted in 43.6% contaminated seeds. Germination rates above 80% were recorded. Low concentrations of nitrogenous salts and macronutrients produced greater than 76% survival and promoted greater in vitro plant development than the complete MS medium. The development of the aerial system, root system, fresh mass and photosynthetic pigments were positively related to sucrose concentration in vitro. The highest sucrose concentration also indirectly promoted greater development of the aerial system and fresh mass of acclimatized plants. We established conditions for in vitro cultivation and acclimatization for efficient propagation of V. flammea with a view towards conservation of the species or reestablishment of natural populations.

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.

The present study evaluated the genotoxic effects of the atmospheric air on Tradescantia pallida var. purpurea in urban areas with different intensities of vehicular traffic and in riparian forest fragments in the Sinos River Basin (Rio Grande do Sul, Brazil), considering the influence of climatic conditions prevailing in these environments. Bimonthly, from May 2012 to March 2013, cuttings with flower buds were exposed for 8 h in urban and riparian forest environments in the municipalities of Caraá, Taquara and Campo Bom in the upper, middle and lower sections, respectively, of the Sinos River Basin. Simultaneously, negative controls were made and climatic data were recorded. Micronuclei (MCN) frequencies were determined in young tetrads of pollen mother cells and expressed as MCN/100 tetrads. Significantly higher MCN frequencies were observed in buds exposed in urban and riparian forest environments in Taquara (up to 7.23 and 4.80, respectively) and Campo Bom (up to 4.90 and 4.23, respectively) than in buds exposed in Caraá (up to 2.90 and 2.50, respectively), in the majority of samplings, and in relation to the negative control (up to 1.93) in all months. Over the course of the period monitored, there were significant variations in MCN frequencies at all sampling points, with the exception of the urban environment in Caraá. For the urban environments, relation between the MCN frequency, vehicular traffic and mean temperature was observed. For the riparian forest fragments, there was no association between MCN frequency and climatic factors. Tradescantia pallida var. purpurea can be considered a useful tool to point out areas with increased atmospheric pollution, since the exposure of plants under severe climatic conditions is avoided to minimize their negative influence on the formation of micronuclei.Keywords: abiotic factors, vehicular emissions, bioindicator, environmental quality, micronucleus. Biomonitoramento do potencial genotóxico do ar em