Trophic cascades within and across ecosystems: The role of anti-predatory defences, predator type and detritus quality.

Species in one ecosystem can indirectly affect multiple biodiversity components and ecosystem functions of adjacent ecosystems. The magnitude of these cross-ecosystem effects depends on the attributes of the organisms involved in the interactions, including traits of the predator, prey and basal resource. However, it is unclear how predators with cross-ecosystem habitat interact with predators with single-ecosystem habitat to affect their shared ecosystem. Also, unknown is how such complex top-down effects may be mediated by the anti-predatory traits of prey and quality of the basal resource. We used the aquatic invertebrate food webs in tank bromeliads as a model system to investigate these questions. We manipulated the presence of a strictly aquatic predator (damselfly larvae) and a predator with both terrestrial and aquatic habitats (spider), and examined effects on survival of prey (detritivores grouped by anti-predator defence), detrital decomposition (of two plant species differing in litter quality), nitrogen flux and host plant growth. To evaluate the direct and indirect effects each predator type on multiple detritivore groups and ultimately on multiple ecosystem processes, we used piecewise structural equation models. For each response variable, we isolated the contribution of different detritivore groups to overall effects by comparing alternate model formulations. Alone, damselfly larvae and spiders each directly decreased survival of detritivores and caused multiple indirect negative effects on detritus decomposition, nutrient cycling and host plant growth. However, when predators co-occurred, the spider caused a negative non-consumptive effect on the damselfly larva, diminishing the net direct and indirect top-down effects on the aquatic detritivore community and ecosystem functioning. Both detritivore traits and detritus quality modulated the strength and mechanism of these trophic cascades. Predator interference was mediated by undefended or partially defended detritivores as detritivores with anti-predatory defences evaded consumption by damselfly larvae but not spiders. Predators and detritivores affected ecosystem decomposition and nutrient cycling only in the presence of high-quality detritus, as the low-quality detritus was consumed more by microbes than invertebrates. The complex responses of this system to predators from both recipient and adjacent ecosystems highlight the critical role of maintaining biodiversity components across multiple ecosystems.

As espécies em um ecossistema podem afetar indiretamente múltiplos componentes da biodiversidade e funções ecossistêmicas em ecossistemas adjacentes. A magnitude destes efeitos entre ecossistemas depende dos atributos dos organismos envolvidos nas interações, incluindo características do predador, da presa e do recurso basal. No entanto, não está claro como os predadores com habitat em múltiplos ecossistemas interagem com predadores de um ecossistema único, e como isso afeta o ecossistema partilhado entre eles. Além disso, não se sabe como esses efeitos complexos do tipo top­down podem ser mediados pelas características antipredatórias da presa e pela qualidade do recurso basal. Usamos as teias alimentares de invertebrados aquáticos de bromélias­tanque como um sistema modelo para investigar essas questões. Nós manipulamos a presença de um predador estritamente aquático (larvas de zigópteros) e um predador com habitats terrestre e aquático (aranha), e examinamos os efeitos na sobrevivência de presas (grupos de detritívoros com diferentes estratégias de defesa antipredatória), decomposição de detritos foliares (de duas espécies de plantas diferindo na qualidade foliar), fluxo de nitrogênio e crescimento da planta hospedeira. Para avaliar os efeitos diretos e indiretos de cada tipo de predador em múltiplos grupos de detritívoros e, finalmente, em múltiplos processos ecossistêmicos, utilizamos modelos de equações estruturais por partes (piecewiseSEM). Para cada variável resposta, isolamos a contribuição de diferentes grupos de detritívoros bem como seus efeitos globais, comparando modelos alternativos. Larvas de zigópteros e aranhas diminuíram diretamente a sobrevivência dos detritívoros e causaram múltiplos efeitos negativos indiretos na decomposição de detritos, na ciclagem de nutrientes e no crescimento da planta hospedeira. No entanto, quando os predadores coocorreram, a aranha causou um efeito negativo não consumível na larva de zigóptero, diminuindo os efeitos líquidos, diretos e indiretos, do tipo top­down na comunidade de detritívoros aquáticos e no funcionamento do ecossistema. Tanto os atributos antipredatórios dos detritívoros quanto a qualidade dos detritos modularam a força e o mecanismo dessas cascatas tróficas. A interferência do predador foi mediada por detritívoros indefesos ou com defesa parcial. Entretanto, os detritívoros com defesas antipredatórias escaparam do consumo por larvas de zigópteros, mas não por aranhas. Predadores e detritívoros afetaram a decomposição do ecossistema e a ciclagem de nutrientes apenas na presença de detritos de alta qualidade, uma vez que os detritos de baixa qualidade foram consumidos mais por micróbios do que por invertebrados. As respostas complexas deste sistema aos predadores tanto de ecossistemas receptores quanto adjacentes destacam o papel crítico da manutenção dos componentes da biodiversidade em múltiplos ecossistemas.

Functional traits of predators and decomposer prey determine context dependency in trophic control over ecosystems.

Research Highlight: Piccoli, G. C. d. O., Antiqueira, P. A. P., Srivastava, D. S., & Romero, G. Q. (2024). Trophic cascades within and across ecosystems: The role of anti-predatory defences, predator type and detritus quality. Journal of Animal Ecology, 00, 1-14. https://doi.org/10.1111/1365-2656.14063. Ecosystem functioning is controlled by the interplay between bottom-up supply of limiting nutrients and top-down animal feedback effects. However, the degree of animal versus nutrient control is context-dependent. A key challenge lies in characterizing this context dependency which is hypothesized to depend on differences in animal functional traits. Reporting on an important experiment, Piccoli et al. (2014) evaluate how interactions among functionally different predators and decomposer prey create context dependency in top-down control of a model system-tropical bromeliad tank ecosystems. Bromeliad plants hold water in their tanks supporting microcosm ecosystems containing terrestrial and aquatic insect larvae and arachnids. The ecosystems are supported by nutrients in plant litter that rains down from forest canopies into the tanks. Nutrients are released after litter is decomposed by a functionally diverse community of larval insect decomposers that differ in feeding mode and antipredator defence strategy. This decomposer community is preyed upon by an exclusively narrowly ranging aquatic insect larval predator and widely ranging spider predator that crosses between the aquatic and surrounding terrestrial ecosystems. Experimental manipulation of the animal community to test for the degree of control by predators mediated by the functionally diverse prey community included four treatments: (i) a control with the detritivores composing different function groups but without predators, (ii) the cross-ecosystem spider predator added, (iii) the purely aquatic damselfly larvae predator added and (iv) both predator types added to capture their interacting effect on ecosystem function (decomposition, nutrient release, and plant growth). Notably, the study resolved the causal pathways and strengths of direct and indirect control using structural equation modelling. These findings reveal how context dependency arises due to different capacities of the predators alone and together to overcome prey defences and control their abundances, with attendant cascading effects that diminished as well as enhanced decomposition and nutrient release to support bromeliad plant production. The study reveals that predators have a decided, albeit qualitatively and quantitatively different, hand in shaping the degree of bottom-up control through feedback effect on the release of limiting nutrients. This ground-breaking study provides a way forward in understanding the mechanisms determining context dependency in the control over ecosystem functioning.

Investigating the reproductive strategies of Deuterocohnia meziana (Bromeliaceae), an endangered and restricted species from South American rocky outcrops.

Studies of reproductive biology and resources availability to floral visitors by plant species are important to understand the plant-pollinator interactions that drive species adaptation. We aim to understand the relationship between reproduction mechanisms of Deuterocohnia meziana (Bromeliaceae) and pollinators. The species occurs in Bolivia and Paraguay, and it is the only species of the genus found in Brazil, where it is restricted to ironstone outcrops. These areas are currently threatened by the iron mining industry. Additionally, they face risks from fire occurrence and grazing by cattle. We analyzed the floral biology, reproductive system, phenology, and pollination ecology of a natural population of Deuterocohnia meziana, from ironstone outcrops in Brazil. The species exhibits diurnal anthesis, with stigma receptive throughout anthesis, and 77% of pollen viability. Deuterocohnia meziana produces relatively large amounts of nectar, especially early in the morning (32.8 ± 9.4 µl), with a mean sugar concentration of 23.5 (± 3.2) ºBrix. It is self-incompatible with a peak flowering occurring in August (dry season), although flowers are observed continuously throughout the year. The species exhibits two types of inflorescences, young and mature, among which an average of 13.1 and 3.6 flowers open per day, respectively. Hummingbirds and bees are the effective pollinators, although butterflies and ants also visit D. meziana flowers. The species is reliant on exogenous pollen and pollinators for fruit set. The continuous conservation of D. meziana populations and their communities is essential for preserving plant-pollinator mutualism and the floral community adapted to ironstone outcrops.

Distribution pattern in the rupiculous genus Orthophytum (Bromelioideae/Bromeliaceae) reveals high microendemicity in different types of rocky outcrops.

This study aimed to recognize the biogeographic patterns, richness, and diversity levels of the Brazilian endemic genus Orthophytum and identify their biotic components through a parsimony analysis of endemicity (PAE), to better understand the evolutionary history of this group and develop strategies for the conservation of its species. We prepared a database for the 54 currently known species of Orthophytum, including their geographical locations as obtained from digital databases of the principal herbaria of Brazil, Europe, and the USA. A parsimony analysis of endemicity (PAE) was used to delimit the areas of endemism based on two grids' sizes (1º x 1º and 2º × 2º). The majority rule consensus tree resulting from the PAE indicated three areas of endemism with high bootstrap, diversity, and richness indices: the northern portion of the Espinhaço Range, the southern portion of the Espinhaço Range, and the central portion of the Atlantic Forest. The recognition of those distribution patterns reveals a high number of microendemic species, which is discussed here.

Increased Multiplication Rates of Vriesea hieroglyphica (Carriere) E. Morren Through a Temporary Immersion System.

The main difficulty for the cultivation and conservation of bromeliad species is the reduced number of propagules and slow growth of many of the species, resulting in a low propagation efficiency. Bromeliad plants are hardy and relatively easy to cultivate, with a high ornamental and ecological importance. Aiming at efficient micropropagation rates of V. hieroglyphica, a highly valued bromeliad, with very low propagation efficiency, a temporary immersion system was used and compared to semisolid and liquid static medium. Cultures obtained from in vitro germinated seeds were used as explants, maintaining their genetic diversity. Micropropagation with this simple temporary immersion system, composed of two autoclavable flasks, each with one opening for the attachment of 22 µm syringe filters, connected by a rubber stopper and an inner glass tube. In the bottom flask, an air valve is attached to the filter, which is subsequently connected to an aquarium pump and a timer and plugged to an outlet. This simple temporary immersion system showed improved micropropagation efficiency and is a method that can also be evaluated for other species.

Drought memory in Acanthostachys strobilacea, a CAM epiphytic bromeliad.

Stress memory is the development of altered responses to stress due to previous exposure, which might result in increased tolerance. Biochemical and physiological parameters shown to be positively affected by stress memory include those of the antioxidant and nitrosative metabolism, photosynthetic pigments and osmolyte content. Epiphytic bromeliads likely present stress memory since they experience frequent droughts in the canopies. Thus, we aimed to evaluate if the epiphytic bromeliad Acanthostachys strobilacea (Schult. & Schult.f.) Klotzsch shows improved metabolic stress defence responses to a second drought and rewatering cycle compared to a single exposure. In a controlled environment chamber, 90-day-old plants were exposed to one or two drought-rewatering cycles of 14 days without irrigation and 5 days of rewatering each. Sampling occurred after the final drought and rewatering periods for one or two cycles treatments. The free amino acid, chlorophyll, and carotenoid levels and S-nitrosoglutathione reductase (GSNOR) activity were higher at the second drought than at the first exposure. The rise in nocturnal acidification (indicative of increased CAM activity) caused by the initial drought persisted through the second drought-rewatering cycle, implying a lasting memory effect on CAM activity. Furthermore, the second recovery did not induce glutathione accumulation, as in the first rewatering event, suggesting the pre-exposure to drought reduced this thiol's demand during a later recovery. Our results evidence metabolic changes related to drought stress memory in A. strobilacea, supporting this mechanism might be involved in the tolerance of epiphytic bromeliads to intermittent droughts.

The Arrow Macambira (Encholirium spectabile: Bromeliaceae) as an Important Habitat for the Arthropod Fauna in Rocky Outcrops of the Brazilian Semi-Arid Region.

Bromeliads play a vital role in preserving biodiversity in the Neotropical region. To understand their impact on arthropod diversity in Brazil's semi-arid region, we studied the rupicolous bromeliad Encholirium spectabile. From 2011 to 2018, we observed the arthropod fauna in E. spectabile clumps, documenting the associated taxa, their abundance, and interactions. We also investigated how seasonality affects arthropod richness and composition during the dry and rainy seasons. Over the observation period, 15 orders and 57 arthropod families were recorded in association with E. spectabile. Insecta dominated, followed by predatory chelicerates. Eight usage categories were identified, with Shelter being the most prevalent, followed by Predators, Nesters, and Nectarivores. Significant differences in taxonomic richness were noted between rainy and dry seasons, with the rainy season exhibiting higher diversity. Seasonal variation was also observed in species composition. Clumps of E. spectabile emerged as crucial habitats for surrounding arthropod fauna. This research underscores the importance of non-phylotelm bromeliads, particularly in high abiotic stress environments like semi-arid regions. The taxonomic diversity observed aligns with findings from diverse environments, shedding light on the relevance of E. spectabile for associated arthropod fauna. These results prompt further exploration of non-phylotelm bromeliads in semi-arid settings, providing a fresh perspective on their significance in shaping arthropod communities.

Demographic structure across all known populations of the rheophyte Dyckia brevifolia Baker (Bromeliaceae) in the Itajaí-Açu River, Southern Brazil.

Understanding the distribution and demographic structure of populations is essential for species conservation. In Brazil, the rheophyte group has been greatly affected by the construction of hydroelectric dams. All know populations of Dyckia brevifolia Baker along Itajaí-Açu River were studied. The plants were classified as seedlings, immature or reproductive rosettes. In addition, the number of dead rosettes, except for seedlings, was determined in five populations of D. brevifolia. The total number of rosettes per population ranged from 273 to 7,185, totaling 30,443 rosettes, and 1,789 seedlings (5.9%). Only 2.4% of rosettes occurred isolated and 97.6% occurred clumped into 2,254 clumps. The number of rosettes per clump ranged from two to 339 rosettes. The percentage of reproductive rosettes per population ranged from 7.8 to 26.7%. The correlation between the number of clumps or between the total number of rosettes and the area of occupation was significant and positive (r = 0.82; P < 0.05). The production of offshoots (1-4) occurred on immature and reproductive rosettes. Dyckia brevifolia has herbivory by Hydrochaeris hydrochaeris (capybara). These rosettes die or often resprout, emitting from 1 to 20 shoots. The populations did not present a pattern of distribution of rosettes in the diametric classes, but in all populations a decrease in the number of rosettes can be observed in the classes with the largest diameter. The small area of occupation (9,185 m2) showed high environmental specificity and vulnerable to habitat loss and environmental changes. Therefore, the maintenance these sites is essential for the long-term conservation of D. brevifolia.

Interactive effects of drought and deforestation on multitrophic communities and aquatic ecosystem functions in the Neotropics-a test using tank bromeliads.

Background: Together with the intensification of dry seasons in Neotropical regions, increasing deforestation is expected to exacerbate species extinctions, something that could lead to dramatic shifts in multitrophic communities and ecosystem functions. Recent studies suggest that the effects of habitat loss are greater where precipitation has decreased. Yet, experimental studies of the pure and interactive effects of drought and deforestation at ecosystem level remain scarce. Methods: Here, we used rainshelters and transplantation from rainforest to open areas of natural microcosms (the aquatic ecosystem and microbial-faunal food web found within the rainwater-filled leaves of tank bromeliads) to emulate drought and deforestation in a full factorial experimental design. We analysed the pure and interactive effects of our treatments on functional community structure (including microorganisms, detritivore and predatory invertebrates), and on leaf litter decomposition in tank bromeliad ecosystems. Results: Drought or deforestation alone had a moderate impact on biomass at the various trophic level, but did not eliminate species. However, their interaction synergistically reduced the biomass of all invertebrate functional groups and bacteria. Predators were the most impacted trophic group as they were totally eliminated, while detritivore biomass was reduced by about 95%. Fungal biomass was either unaffected or boosted by our treatments. Decomposition was essentially driven by microbial activity, and did not change across treatments involving deforestation and/or drought. Conclusions: Our results suggest that highly resistant microorganisms such as fungi (plus a few detritivores) maintain key ecosystem functions in the face of drought and habitat change. We conclude that habitat destruction compounds the problems of climate change, that the impacts of the two phenomena on food webs are mutually reinforcing, and that the stability of ecosystem functions depends on the resistance of a core group of organisms. Assuming that taking global action is more challenging than taking local-regional actions, policy-makers should be encouraged to implement environmental action plans that will halt habitat destruction, to dampen any detrimental interactive effect with the impacts of global climate change.

Semi-arid's Unsung Heroes: Hymenoptera and the Vital Ecosystem Services Enabled by Encholirium spectabile, a Rupicolous Bromeliad in the Brazilian Semi-arid Region.

The concept of Ecosystem Services (ES) recognizes the importance of natural ecosystems in supporting human well-being. Hymenoptera, a diverse group of insects including ants, bees, and wasps, play crucial roles in providing ESs. Despite their significance, the provision of ESs by Hymenoptera is often undervalued, leading to ecosystem degradation and loss of important services. This study focuses on the association between Hymenoptera and a rupicolous bromeliad species (Encholirium spectabile) and explores the ESs promoted directly and indirectly by these insects. The study area is located in the Caatinga region of Brazil, characterized by irregular rainfall and a dry season. The results show that Hymenoptera, particularly bees, ants, and wasps, provide a range of ESs including pollination, honey production, pest control, cultural symbolism, and educational value. These services are vital for plant reproduction, food production, and ecosystem functioning in both seasons; there are no differences in species richness between seasons, but rather in species composition. Understanding the importance of Hymenoptera for ESs is crucial for informing conservation and management practices to ensure the sustainability of natural ecosystems. The study highlights the need for conservation actions to protect the intricate ecological relationships between Hymenoptera and bromeliads, which indirectly support ESs by providing habitat and resources, especially during droughts when resources are scarce in the region. By recognizing the importance of bromeliads in supporting Hymenopteran communities, conservation efforts can focus on preserving these critical ecological interactions and maintaining ES provision.

Phytochemical profile and biological activities of Bromelia antiacantha extracts / Perfil fitoquímico e atividades biológicas de extratos de Bromelia antiacantha

Reports from popular medicine usually act as a basis for the development of new drugs from natural compounds with therapeutic actions for serious diseases and prevalence such as cancer. Bromelia antiacantha Bertol. is a species of the Bromeliaceae family, considered an unconventional food plant, found in the south and midwest regions of Brazil. Despite the high nutritional content and pharmacological potential of its fruits, few scientific studies report its biological actions. Thus, this study evaluates the phytochemical profile of aqueous and ethanol extracts obtained from B. antiacantha fruits, as well as their possible antioxidant, antitumor, and cytotoxic activities. The aqueous extract exhibited phenolic compounds and flavonoids, while ethanol extracts indicated the presence of flavonoids and coumarin in their composition, regardless of the region of collection. The ethanolic extract demonstrated a more promising antioxidant effect than the aqueous extract and also induced a significant inhibition in the viability of human cervical cancer cells of the SiHa strain. In addition, treatment with both extracts did not alter the viability of non-tumor cells of the immortalized human keratinocyte lineage (HaCaT). These results bring new data about extracts obtained from a native plant, edible and traditionally used in popular medicine, opening new perspectives for its possible therapeutic application.

Relatos da medicina popular costumam atuar como referencial para o desenvolvimento de novos fármacos a partir de moléculas naturais com ações terapêuticas para doenças de alta gravidade e prevalência como o câncer. Bromelia antiacantha Bertol. é uma espécie da família Bromeliaceae, considerada uma planta alimentícia não convencional (PANC), encontrada nas regiões sul e centro-oeste do Brasil. Apesar do alto teor nutritivo e potencial farmacológico de seus frutos, poucos estudos científicos relatam suas ações biológicas. Desta forma, este estudo avalia o perfil fitoquímico de extratos aquoso e etanólico obtidos de frutos de B. antiacantha, bem como a sua possível ação antioxidante, antitumoral e citotóxica. O extrato aquoso apresentou compostos fenólicos e flavonoides, enquanto os extratos etanólicos apontam a presença de flavonóides e cumarina em sua composição, independente da região de coleta. O extrato etanólico demonstrou efeito antioxidante mais promissor do que o extrato aquoso e também induziu uma inibição significativa na viabilidade de células humanas de câncer cervical da linhagem SiHa. Além disso, o tratamento com ambos extratos não alterou a viabilidade de células não tumorais da linhagem de queratinócitos humanos imortalizados (HaCaT). Estes dados trazem novas informações sobre extratos obtidos de uma espécie vegetal nativa, comestível e já utilizada tradicionalmente, mas abrindo novas perspectivas quanto a possíveis aplicações terapêuticas.

Seed mass maturity in the terrestrial bromeliad Hechtia perotensis (Bromeliaceae), endemic to Mexico / Madurez de las semillas en la bromelia terrestre Hechtia perotensis (Bromeliaceae), endémica de México

Abstract Introduction: H. perotensis is a plant with a high potential for ecological restoration because it yields thousands of seeds and grows under low levels of rain, poor soils and contrasting temperatures. However, little is known of the seed mass maturity (high seed germination, low seed fresh weight and low seed moisture content) in this species. Objective: Assess seed germination in the laboratory of H. perotensis during seed development and along the floral stalk (infructescence) in two sites one in rocky location and another near a lake. The hypothesis was that there is a time after flowering in which seeds have highest germination and fresh weight and that the apical, centre and base of the infructescence are different in seed germination and fresh weight in both sites. Methods: Capsules were collected in two sites one in rocky land (Frijol Colorado, Perote, Veracruz) and another near one lake (Alchichica, Puebla), in the months of August, September and November 2016 and January 2017. A repeated measure design (RMD) was used to analyze the effects of infructescence section on seed weight, moisture content and seed germination (41, 87, 152 and 215 days after flowering). Each evaluation time comprised five replicates, each one with 15 seeds. Results: Difference in seed germination, seed weight and moisture content between sections of the infructescence was not significant. However, significant differences were found not only between first and last sample dates, but mainly between first and second dates. Eighty-seven days after flower pollination seed moisture content was lower than 20 % and up to 80 % of seed germinated in both sites of sampling. Conclusions: In this study it was found that the moisture content of H. perotensis seed can be used as an indicator of the physiological maturity of the seed and it is also related to germination of the seed.

Resumen Introducción: H. perotensis es una planta con un alto potencial para la restauración ecológica debido a que produce miles de semillas y crece con niveles bajos de lluvia, suelos pobres y temperaturas contrastantes. Sin embargo, el desarrollo de la madurez de las semillas (germinación alta, baja humedad y bajo peso fresco de semilla) en esta especie es muy poco conocido. Objetivo: Evaluar la germinación en el laboratorio de las semillas de H. perotensis, durante el desarrollo de la semilla y a lo largo del tallo floral (infrutescencia) en dos sitios; uno en un área rocosa y otro cerca de un lago. La hipótesis fue que hay un tiempo después de la floración, en el que las semillas presentan la mayor germinación y menor peso fresco, y que las secciones apical, central y base de la infrutescencia, la germinación y el peso fresco de la semilla son diferentes en los dos sitios. Métodos: se recolectaron las cápsulas en dos sitios uno en un área rocosa (Frijol Colorado, Perote, Veracruz) y otro cerca de un lago (Alchichica, Puebla), en los meses de Agosto, Septiembre y Noviembre de 2016 y Enero de 2017. Se usó un diseño de medidas repetidas (DMR) para analizar los efectos de la sección de la infrutescencia sobre el peso fresco de la semilla, el contenido de humedad y la germinación de la semilla (41, 87, 152 y 215 días, después de la floración). Cada tiempo de evaluación comprendió cinco réplicas y 15 semillas. Resultados: La diferencia en la germinación de la semilla, el peso de la semilla y el contenido de humedad entre las secciones de la infrutescencia no fue significativa. Sin embargo, se encontraron diferencias significativas entre las fechas de muestreo inicial y final, pero sobre todo entre la primera y la segunda fecha. Asimismo, ochenta y siete días después de la polinización de las flores, el contenido de humedad de las semillas fue inferior al 20 % y superior al 80 % en la germinación de las semillas en ambos sitios de muestreo. Conclusiones: en este estudio se encontró que el contenido de humedad de la semilla de H. perotensis, puede usarse como un indicador de la madurez fisiológica de la semilla y también está relacionado con la germinación de la semilla.

Conservation of Vriesea flammea L. B. Sm., an endemic Brazilian bromeliad: effects of nutrients and carbon source on plant development / Conservação de Vriesea flammea L. B. Sm., uma bromélia Brasileira endêmica: efeitos dos nutrientes e fonte de carbono sobre o desenvolvimento das plantas

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.

Resumo Bromeliaceae é restrita à região neotropical, com alto grau de endemismo, que contribui para o aumento da biodiversidade, devido às características morfológicas dos indivíduos. Objetivando desenvolver uma tecnologia in vitro de conservação para obtenção de plantas com vistas à reintrodução, sementes de Vriesea flammea L.B.Sm. foram coletadas, esterilizadas, germinadas em meio de cultura e as plantas obtidas foram cultivadas por 180 dias em meio MS com diferentes concentrações de nutrientes minerais (25 e 50% dos sais nitrogenados e dos macronutrientes), bem como em diferentes concentrações de sacarose (20, 30, 40, 50 e 60 g L-1). Após, as plantas foram aclimatizadas por 150 dias em substrato comercial. Quando da esterilização das sementes, apenas 4% destas contaminaram. Por sua vez, a esterilização de cápsulas resultou em 43,6% de sementes contaminadas. Taxas de germinação superiores a 80% foram registradas. Baixas concentrações dos sais nitrogenados e de macronutrientes proporcionaram sobrevivência superior a 76% e promoveram maior desenvolvimento das plantas in vitro do que o meio MS completo. O desenvolvimento do sistema aéreo, radicular, a massa fresca e pigmentos fotossintéticos apresentaram relação positiva com a concentração de sacarose in vitro. A maior concentração de sacarose também propiciou indiretamente maior desenvolvimento do sistema aéreo e massa fresca das plantas aclimatizadas. Estabelecemos as condições de cultivo in vitro e aclimatização para a eficiente propagação de V. flammea com vistas à conservação da espécie ou reestabelecimento das populações naturais.

Heterotrophic flagellates (Amorpha and Diaphoretiches) in phytotelmata bromeliad (Bromeliaceae) / Flagelados heterotróficos (Amorpha e Diaphoretiches) em fitotelmata de bromélia (Bromeliaceae)

Abstract Many plants may accumulate rainwater, forming phytotelmata, aquatic microhabitats inhabited by various organisms. The aim of this study was to conduct an inventory of heterotrophic flagellates associated with phytotelmata of the bromeliad Aechmea distichantha Lem., found in rocky cliffs on the Upper Paraná River. The bromeliads were removed manually from the rocky wall, the water was removed and cultures of organisms of each plant were mounted in Petri dishes. Sixteen species of heterotrophic flagellate were recorded, drawn and described, among them one species belonging to the Amorpha Domain and 15 species to the Diaphoretiches Domain. The groups with most species were Euglenida and Kinetoplastea. The low diversity of heterotrophic flagellates recorded in this study, compared to the plankton of lakes and reservoirs, is probably related to the fact that phytotelmata are habitats with extreme environmental conditions, thus selecting organisms tolerant to these environments.

Resumo Em sua superfície externa, muitas plantas podem acumular água da chuva formando fitotelmata, ou seja, micro-habitat aquáticos colonizados por diversos organismos, entre eles, os flagelados protistas. Fez-se um inventário de flagelados heterotróficos associados ao fitotelmata da bromélia Aechmea distichantha Lem., encontrada em paredões rochosos em um trecho da bacia do alto rio Paraná. As bromélias foram retiradas manualmente de paredão rochoso e, em laboratório, a água foi retirada dos tanques de cada planta, e foram montadas culturas dos organismos em placas de Petri. Os flagelados heterotróficos foram, então, observados in vivo sob microscópio óptico Olympus BX51, com sistema de contraste de interferência diferencial (DIC) acoplado. Dezesseis espécies flagelados heterotróficos foram registradas, desenhadas e descritas, sendo uma espécie pertencente ao Domínio Amorpha e 15 espécies ao Domínio Diaphoretiches. Os grupos mais especiosos foram Euglenida e Kinetoplastea. A diversidade relativamente reduzida de flagelados heterotróficos, quando comparada ao plâncton de lagos e reservatórios, pode estar relacionada ao fato de os fitotelmata serem habitats limitados, com condições ambientais extremas, selecionando, assim, organismos tolerantes a esses ambientes.

Micropropagation and in vitroconservation of Alcantarea nahoumii (Bromeliaceae), an endemic and endangered species of the Brazilian Atlantic Forest

Alcantarea nahoumii(Leme) J. R. Grant is a species native to theAtlantic Forest that stands out for ornamental purposes. The objective of this work was to evaluate the in vitrogerminationof A. nahoumiiseeds and establish a micropropagation protocol for production of seedlings so as to minimize the effects of predatory extractivism and develop an in vitroconservation system. Mature seeds were disinfested, established in three culture media (MS, MS½ and MS⅓) and incubated at four temperatures (20, 25, 30 and 35ºC)in a germination chamber. In the micropropagation experiment, stem segments were introduced in MS medium supplemented with 0.5 μM of 1-naphthaleneacetic acid (NAA) and 0.0, 2.2, 4.4 and 6.6 μM of 6-benzylaminopurine (BAP). For the in vitroconservation, plantlets were established in MS or MS½ medium supplemented with 15 g L-1or 30 g L-1of sucrose. The plants were acclimated with commercial substrate. The highest seed germination percentages were promoted by temperature conditions of 20 and 25ºC, with MS culture medium. The highest multiplication rate of shoots was obtained from the treatment without addition of the growth regulator or when combined with 2.2 μM of BAP + 0.5 μM of NAA. The acclimation of the plants occurred with high survival rate. The species can be conserved in vitrounder slow growth condition for 24 months when incubated in MS medium supplemented with 30 g L-1of sucrose.

Distribución geográfica de angiospermas epífitas de la región terrestre prioritaria Cerros Negro-Yucaño, Oaxaca, México / Geographical distribution of epiphytic angiosperms of the priority terrestrial region of Cerros Negro-Yucaño, Oaxaca, Mexico

Resumen El conocimiento sobre la riqueza y la distribución de las plantas epifítas vasculares es aún incompleto en muchas áreas de México. Un ejemplo es la región terrestre prioritaria (RTP) Cerros Negro-Yucaño, que se ubica en el noroeste del estado de Oaxaca y pertenece a la región mixteca alta (Ñuu Savi Sukun, Ñuu vixi). Con base en la revisión de material de herbario en 12 colecciones institucionales mexicanas y en la recolección de especímenes en algunas localidades, principalmente cubiertas por bosque de encino, en 17 de los 18 municipios que incluye la RTP, se compilo un listado de las angiospermas epífitas. Se registró la presencia de 40 especies, distribuidas en 13 géneros y cinco familias; 28 taxa son endémicos de México y tres de ellos se conocen solamente de Oaxaca. Los géneros Tillandsia (18 spp.) y Peperomia (4) fueron los mejor representados en el área. El bosque de encino fue el tipo de vegetación en el cual se encontraron más epífitas (32 spp.) y también el intervalo altitudinal de 1 900 a 2 100 m (19 spp.). Plantas en floración de Artorima erubescens, Laelia albida, L. furfuracea y Prosthechea karwinskii, son utilizadas por pobladores de la región como ornamentales, durante las celebraciones religiosas de Día de Muertos y Semana Santa. Este impacto humano podría representar una amenaza para las poblaciones silvestres de estas especies en el futuro.(AU)

Abstract The knowledge on richness and distribution of epiphytic vascular plants is still incomplete in many areas of Mexico. An example is the terrestrial priority region (RTP) Cerros Negro-Yucaño, which is located in the Northwest portion of Oaxaca and belongs to the Mixteca Alta Region (Ñuu Savi Sukun, Ñuu Vixi). Based on herbarium material revision of 12 Mexican institutional collections and the collection of specimens in some localities, mainly covered by oak forest, in 17 of the 18 municipalities included in the RTP, we compiled a list of epiphytic angiosperms. The presence of 40 species, distributed in 13 genera and five families was recorded; 28 taxa are endemic to Mexico and three of them are only known from Oaxaca. The genera Tillandsia (18 spp.) and Peperomia (4) were the best represented genera in the area. Oak forest was the type of vegetation in which the most of the epiphytes were found (32 spp.), and also the altitudinal range between 1 900 and 2 100 m (19 spp.). Flowering plants of Artorima erubescens, Laelia albida, L. furfuracea, and Prosthechea karwinskii are used by the local people as ornamentals during the religious celebrations of Day of the Dead (Mexico) and Holly Week. This human impact might be a threat to the wild populations of these species in the future.(AU)

Cosmarium bromelicola sp. nov. (Desmidiaceae, Zygnematophyceae), a new desmid species from Northeast Brazil / Cosmarium bromelicola sp. nov. (Desmidiaceae, Zygnematophyceae), uma nova espécie de desmídia do nordeste do Brazil

Abstract Cosmarium bromelicola sp. nov. is a new desmid species described from samplings carried out in bromeliad tanks (phytotelmata) from an area of rocky outcrops at Serra da Jiboia, Bahia State, Northeast Brazil. Presence of subtrapeziform cells with a deep depression at the apical region and twisted X-shaped cell in side view are the diagnostic features for the species. Relationships with the morphologically closest taxa are discussed.

Resumo Cosmarium bromelicola sp. nov. é uma nova espécie de desmídia descrita a partir de amostragens realizadas em tanques de bromélias (fitotelmata) de uma área de afloramentos rochosos na Serra da Jiboia, Bahia, nordeste do Brasil. A presença de células trapeziformes com uma depressão profunda na região apical e célula em forma de X em vista lateral são as características diagnósticas da espécie. Relações com os táxons morfologicamente próximos são discutidas.

Responses of antioxidant enzymes, photosynthetic pigments and carbohydrates in micropropagated Pitcairnia encholirioides L.B. Sm. (Bromeliaceae) under ex vitro water deficit and after rehydration / Respostas de enzimas antioxidantes, pigmentos fotossintéticos e carboidratos em Pitcairnia encholirioides L.B. Sm. (Bromeliaceae) micropropagadas, sob déficit hídrico ex vitro e após reidratação

Abstract In this study, the activities of antioxidant enzymes, photosynthetic pigments, proline and carbohydrate contents in Pitcairnia encholirioides under ex vitro conditions of water deficit were evaluated. Results show that plants under progressive water stress, previously in vitro cultured in media supplemented with 30 g L-1 sucrose and GA3, accumulated more proline and increased peroxidase (POD) activity and the contents of photosynthetic pigments and carbohydrates. For plants previously in vitro cultured with 15 g L-1 sucrose and NAA, no differences were found for proline content and there were reductions in activities of peroxidase (POD), catalase (CAT) and poliphenoloxidase (PPO), and in contents of carbohydrates, with progress of ex vitro water deficit. After rehydration, plants showed physiological recovery, with enzymatic activities and contents of metabolites similar to those found in the controls not submitted to dehydration, regardless of the previous in vitro culture conditions. These results show that micropropagated P. encholirioides has high tolerance to dehydration once in ex vitro conditions, which can ensure the survival of plants from tissue culture when transferred to its natural environment, emphasizing the importance of such biotechnology for the propagation of endangered species.

Resumo Neste estudo, foram avaliadas as atividades de enzimas antioxidantes, pigmentos fotossintéticos, conteúdo de prolina e carboidratos em Pitcairnia encholirioides sob déficit hídrico em condições ex vitro. Os resultados mostraram que as plantas sob estresse hídrico progressivo, previamente cultivadas in vitro em meio de cultura suplementado com 30 g L-1 de sacarose e GA3 acumularam mais prolina e aumentaram a atividade da peroxidase (POD) e os teores de pigmentos fotossintéticos e carboidratos. Para plantas previamente cultivadas in vitro com 15 g L-1 de sacarose e ANA, não foram encontradas diferenças nos conteúdos de prolina e houve reduções nas atividades da peroxidase (POD), catalase (CAT) e polifenoloxidase (PPO), e no conteúdo de carboidratos, com o progresso do déficit hídrico ex vitro. Após a reidratação, as plantas apresentaram recuperação fisiológica, com atividades enzimáticas e conteúdo de metabólitos semelhantes aos encontrados nos controles não sujeitos à desidratação, independentemente das condições de cultivo in vitro. Estes resultados mostram que P. encholirioides micropropagada tem alta tolerância à desidratação uma vez em condições ex vitro, o que pode garantir a sobrevivência de plantas provenientes da cultura de tecidos quando transferidas para seu ambiente natural, enfatizando a importância desta biotecnologia para a propagação de espécies ameaçadas.

The Tillandsia genus: history, uses, chemistry, and biological activity / El género Tillandsia: historia, usos, química y actividad biológica

Tillandsia L. genus comprises 649 species, with different uses at different times. T. usneoides L. uses are reported since the late- archaic and pre-Columbian cultures. In XIX-XX centuries, T. usneoides was used in some manufactured products, as polish and packing fruit. Tillandsia has a favorable reputation as medicine: for leucorrhea, rheumatism, ulcers, hemorrhoid treatment, as an anti-diabetic remedy, emetic, analgesic, purgative, contraceptive, antispasmodic and diuretic. Tillandsia chemical composition includes cycloartane triterpenes and hydroxy-flavonoids, which are present in at least 24 species. Several extracts and compounds from Tillandsia spp. have been reported with pharmacological actions, as anti-neoplasia, hypolipidemic, antifungal, anti-HSV-1, hypoglycemic and microbicide. This review communicates the economic importance, ethnobotany, chemistry composition and biological activities of the Tillandsia genus, and analyze its biological and economic perspective. Tillandsia genus has cultural, economic and pharmacological relevance, with a high potential in many essential aspects of the modern society.

El género Tillandsia L. comprende 649 especies, con diferentes usos en diferentes épocas. T. usneoides L. se han reportado desde el arcáico tardío hasta las culturas precolombinas. En los siglos XIX-XX, T. usneoides se usó en productos manufacturados: como abrasivo y embalaje de fruta. Como medicina tradicional, el género Tillandsia se reporta para leucorrea, reumatismo, úlceras, hemorroides, remedio antidiabético, emético, analgésico, purgante, anticonceptivo, antiespasmódico y diurético. Su composición química incluye triterpenos de tipo ciclo-artano e hidroxi-flavonoides, presentes en al menos 24 especies. Los extractos y compuestos del género Tillandsia se han reportado con propiedades antineoplásicas, hipolipidémicas, antifúngicas, anti-HSV-1, hipoglucemiantes y microbicidas. Esta revisión comunica la importancia económica, etnobotánica, composición química y las actividades biológicas del género Tillandsia, y analiza su perspectiva biológica y potencial económica. Tillandsia tiene importancia cultural, económica y farmacológica, con gran potencial en muchos aspectos esenciales de la sociedad moderna.

Influence of N-P-K fertilization at the acclimatization stage on micropropagated seedlings of Tillandsia bulbosa Hook / Influência da adubação com N-P-K na fase de aclimatização em mudas micropropagadas de Tillandsia bulbosa Hook

Bromeliads are known worldwide for their ornamental potential. In Brazil, species of the genus Tillandsia occur in the Atlantic rainforest, Amazon rainforest, and rocky fields. This work aimed to evaluate the influence of nitrogen, phosphorus, and potassium fertilization on micropropagated seedlings of Tillandsia bulbosa, at the acclimatization stage, and their leaf anatomy. The experiment was carried out in a completely randomized design, in a 4x4+1 factorial scheme, using coconut coir: earthworm humus: sand mixture as substrate (2:1:1). Urea, single superphosphate, and potassium chloride were used as nitrogen, phosphorus and potassium sources, respectively, at proportions of 50, 100, 200, and 400% of the dose recommended. The doses were distributed in four applications, testing total application at planting (1); ½ application at planting and ½ at 80 DAP (2); application at planting, at 50 DAP, and at 100 DAP (3); and » application at planting, » at 30 DAP, » at 60 DAP, and » at 120 DAP (4); and a control (without fertilization). Leaves anatomy was analyzed at 180 days after planting. Fertilization did not significantly influence the development of seedlings during acclimatization. The doses of 50, 100, and 200% provided thicker parenchyma of chlorophyll and aquifer and leaf blade. Tillandsia bulbosa can be acclimatized without fertilizer application.

As bromélias são conhecidas mundialmente por seu potencial ornamental. No Brasil, as espécies de Tillandsia podem ser encontradas na Mata Atlântica, Floresta Amazônica e campos rupestres. O objetivo deste trabalho foi verificar a influência de adubação com nitrogênio, fósforo e potássio em plântulas micropropagadas de Tillandsia bulbosa, na fase de aclimatização e na sua anatomia foliar. O experimento foi implantado em delineamento inteiramente casualizado, em esquema fatorial 4x4+1, utilizando como substrato a mistura de pó de coco: húmus de minhoca: areia (2:1:1). Ureia, super fosfato simples e cloreto de potássio foram utilizados como fontes de nitrogênio, fósforo e potássio, nas proporções de 50, 100, 200 e 400% da dose recomendada. As doses foram distribuídas em quatro aplicações, testando aplicação total no plantio (1); ½ no plantio e ½ aos 80 DAP (2); no plantio, aos 50 DAP e aos 100 DAP (3) e » no plantio, » aos 30 DAP, » aos 60 DAP e » aos 120 DAP (4), e uma testemunha (sem adubação). Foi realizado o estudo anatômico das folhas aos 180 dias. A adubação não influenciou significativamente o desenvolvimento das plântulas durante a aclimatização. As doses de 50, 100 e 200% proporcionaram maior espessura de parênquimas clorofiliano e aquífero e do limbo foliar. A aclimatização de Tillandsia bulbosa pode ser realizada sem a necessidade de adubação.