Light intensity mediates phenotypic plasticity and leaf trait regionalization in a tank bromeliad.

BACKGROUND AND AIMS: Phenotypic plasticity allows plants to cope with environmental variability. Plastic responses to the environment have mostly been investigated at the level of individuals (plants) but can also occur within leaves. Yet the latter have been underexplored, as leaves are often treated as functional units with no spatial structure. We investigated the effect of a strong light gradient on plant and leaf traits and examined whether different portions of a leaf show similar or differential responses to light intensity. METHODS: We measured variation in 27 morpho-anatomical and physiological traits of the rosette and leaf portions (i.e. base and apex) of the tank bromeliad Aechmea aquilega (Bromeliaceae) when naturally exposed to a marked gradient of light intensity. KEY RESULTS: The light intensity received by A. aquilega had a strong effect on the structural, biochemical and physiological traits of the entire rosette. Plants exposed to high light intensity were smaller and had wider, shorter, more rigid and more vertical leaves. They also had lower photosynthetic performance and nutrient levels. We found significant differences between the apex and basal portions of the leaf under low-light conditions, and the differences declined or disappeared for most of the traits as light intensity increased (i.e. leaf thickness, adaxial trichome density, abaxial and adaxial trichome surface, and vascular bundle surface and density). CONCLUSIONS: Our results reveal a strong phenotypic plasticity in A. aquilega, particularly in the form of a steep functional gradient within the leaf under low-light conditions. Under high-light conditions, trait values were relatively uniform along the leaf. This study sheds interesting new light on the functional complexity of tank bromeliad leaves, and on the effect of environmental conditions on leaf trait regionalization.

Exploring the mycobiota of bromeliads phytotelmata in Brazilian Campos Rupestres.

The phytotelmata is a water-filled tank on a terrestrial plant, and it plays an important role in bromeliad growth and ecosystem functioning. Even though previous studies have contributed to elucidate the composition of the prokaryotic component of this aquatic ecosystem, its mycobiota (fungal community) is still poorly known. In the present work, ITS2 amplicon deep sequencing was used to examine the fungal communities inhabiting the phytotelmata of two bromeliads species that coexist in a sun-exposed rupestrian field of Southeastern Brazil, namely Aechmea nudicaulis (AN) and Vriesea minarum (VM). Ascomycota was the most abundant phylum in both bromeliads (57.1 and 89.1% in AN and VM respectively, on average), while the others were present in low abundance (< 2%). Mortierellomycota and Glomeromycota were exclusively observed in AN. Beta-diversity analysis showed that samples from each bromeliad significantly clustered together. In conclusion, despite the considerable within-group variation, the results suggested that each bromeliad harbor a distinct fungi community, what could be associated with the physicochemical characteristics of the phytotelmata (mainly total nitrogen, total organic carbon, and total carbon) and plant morphological features.

Simultaneous relocation strategy of bromeliads as epiphytes or terricolous in the Montane Dense Ombrophilous Forest of Parque Estadual da Cantareira, São Paulo State, Brazil / Estratégia de realocação simultânea de bromélias como epífitas ou terrícolas na Floresta Ombrófila Densa Montana do Parque Estadual da Cantareira, Estado de São Paulo, Brasil

Plant relocation resulting from vegetation removal is an important conservation strategy. This work aimed to investigate the simultaneous relocation of the bromeliads Aechmea distichantha Lem. and Wittrockia cyathiformis (Vell.) Leme in epiphytic and terricolous form. These bromeliads were rescued from deforested areas due to the construction of a highway. Both were fixed onto tree trunks or pitchforks or in the soil in a Montane Dense Ombrophilous Forest area of Parque da Estadual Cantareira, São Paulo State, Brazil. After one year A. distichantha maintained 100% survival rate, when transplanted in terricolous and 83.33 % in epiphytic form, while W. cyathiformis was 60% for both relocation forms. We concluded that both bromeliad species could be simultaneously relocated as epiphytes or terricolous. Direct relocation to the ground guarantees practicality, as it is difficult to find trees with forks located at small heights from the ground in which the manual fixing of the plant could be done without equipment.

A realocação de plantas resultante da remoção da vegetação é uma importante estratégia de conservação. Este trabalho objetivou investigar a realocação simultânea das bromélias Aechmea distichantha Lem. e Wittrockia cyathiformis  (Vell.) Leme na forma epífita e terrícola, resgatadas de áreas desmatadas devido à construção de uma rodovia. Ambas foram fixadas em troncos de árvores ou forquilhas ou transplantadas para o solo em uma área de Floresta Ombrófila Densa Montana do Parque Estadual da Cantareira, Estado de São Paulo, Brasil. Após um ano, A. distichantha manteve 100% de sobrevida, quando transplantada na forma terrícola e 83,33% na forma epífita, enquanto W. cyathiformis foi de 60% para ambas as formas de realocação. Concluímos que ambas as espécies de bromélias podem ser realocadas simultaneamente como epífitas ou terrícolas. A realocação direta ao solo garante praticidade, pois é difícil encontrar árvores com forquilhas localizadas a pequenas alturas do solo em que a fixação manual da planta possa ser feita sem equipamentos.

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.

Nest Site Selection during Colony Relocation in Yucatan Peninsula Populations of the Ponerine Ants Neoponera villosa (Hymenoptera: Formicidae).

In the Yucatan Peninsula, the ponerine ant Neoponera villosa nests almost exclusively in tank bromeliads, Aechmea bracteata. In this study, we aimed to determine the factors influencing nest site selection during nest relocation which is regularly promoted by hurricanes in this area. Using ants with and without previous experience of Ae. bracteata, we tested their preference for refuges consisting of Ae. bracteata leaves over two other bromeliads, Ae. bromeliifolia and Ananas comosus. We further evaluated bromeliad-associated traits that could influence nest site selection (form and size). Workers with and without previous contact with Ae. bracteata significantly preferred this species over others, suggesting the existence of an innate attraction to this bromeliad. However, preference was not influenced by previous contact with Ae. bracteata. Workers easily discriminated between shelters of Ae. bracteata and A. comosus, but not those of the closely related Ae. bromeliifolia. In marked contrast, ants discriminated between similar sized Ae. bracteata and Ae. bromeliifolia plants, suggesting that chemical cues and plant structure play an important role. Size was also significant as they selected the largest plant when provided two dissimilar Ae. bracteata plants. Nest site selection by N. villosa workers seems to depend on innate preferences but familiarization with plant stimuli is not excluded.

Nematode trophic structure in the phytotelma of Neoregelia cruenta (Bromeliaceae) in relation to microenvironmental and climate variables.

The term phytotelma (pl. phytotelmata) designates a plant-associated reservoir of fresh water and organic debris. Phytotelmata in tank bromeliads are abundant in tropical forests, and they provide shelter, food, and water for many metazoans. Among the invertebrates known to inhabit phytotelmata, nematodes are the least studied, despite their important role in nutrient and energy cycles in freshwater ecosystems. This study was conceived to characterize the nematode trophic structure in the phytotelma of the bromeliad N. cruenta, and to identify climate and microenvironmental variables that impact it. Nematode abundance (total and per trophic group), rainfall, air temperature, the amount of organic debris fallen into the phytotelma, and eight physico-chemical properties (PCPs) of the water retained in the bromeliad tank - volume; temperature; pH; dissolved organic carbon, nitrogen, oxygen, and solids; and electrical conductivity - were monitored during two years in a natural reserve in Brazil. Bacterial and hyphal feeder nematodes predominated over other trophic groups. Nematode abundance (total and per trophic group) was not impacted by fluctuations in rainfall or air temperature. The amount of organic debris fallen into the phytotelma correlated positively with nematode abundance (total and per trophic group). Regarding the PCPs of water, the only significant correlation - positive - was between the amount of dissolved oxygen and the abundance of hyphal feeder nematodes. These results bring a clearer understanding of the ecology of nematodes inhabiting phytotelmata, which are peculiar and understudied freshwater ecosystems.

Ectopic expression of the Aechmea fasciata APETALA2 gene AfAP2-2 reduces seed size and delays flowering in Arabidopsis.

The Bromeliaceae family, which is distributed pantropically, is one of the most morphologically diverse families. Except for the edible pineapple (Ananas comosus), the vast majority of bromeliads cultivated worldwide are appreciated mainly for their ornamental value. As subtropical and tropical flowering plants, these bromeliads, among with Aechmea fasciata, have significant economic importance. However, the molecular mechanism of flowering in bromeliads remains unrevealed. In this study, an APETALA2 (AP2) homologue, AfAP2-2, which belongs to the AP2/ethylene response element binding protein (AP2/EREBP) transcription factor superfamily, was identified in A. fasciata. AfAP2-2 contains two conserved AP2 domains and is a nuclear-localized transactivator. The expression level of AfAP2-2 was predominantly higher in vegetative organs of the reproductive phase than in those of the vegetative phase. Ectopic expression of AfAP2-2 in Arabidopsis specifically delayed flowering in short-day (SD) conditions. Furthermore, the size and weight of seeds of AfAP2-2-overexpressing Arabidopsis plants were significantly reduced compared to those of the wild type (WT). Our findings suggest that AfAP2-2 might be a negative regulator of flowering and seed size and weight. These results may help facilitate the molecular breeding of bromeliads.

Development, characterization, and transferability of SSR markers for Vriesea carinata (Bromeliaceae) based on RNA sequencing.

PREMISE OF THE STUDY: Expressed sequence tag-simple sequence repeat (EST-SSR) markers were isolated for Vriesea carinata, an endemic bromeliad from the Brazilian Atlantic Forest. These SSR loci may be used to investigate the genetic diversity and population structure of this species and related bromeliads. METHODS AND RESULTS: Based on the transcriptome data of V. carinata, 30 primer pairs were designed and selected for initial validation. Of these primer pairs, 16 generated suitable SSR loci in 69 individuals. The number of alleles per locus ranged from one to 13; the levels of observed and expected heterozygosity per locus ranged from 0.000 to 1.000 and from 0.000 to 0.935, respectively. All loci produced heterologous amplification. Transferability of the loci was tested in 15 species belonging to three Bromeliaceae subfamilies. CONCLUSIONS: The developed EST-SSR markers revealed polymorphism in the four studied populations and could be useful to investigate the genetic diversity of V. carinata and related species. The markers may also be suitable for novel gene annotation and discovery.

Constitutive Expression of Aechmea fasciata SPL14 (AfSPL14) Accelerates Flowering and Changes the Plant Architecture in Arabidopsis.

Variations in flowering time and plant architecture have a crucial impact on crop biomass and yield, as well as the aesthetic value of ornamental plants. Aechmea fasciata, a member of the Bromeliaceae family, is a bromeliad variety that is commonly cultivated worldwide. Here, we report the characterization of AfSPL14, a squamosa promoter binding protein-like gene in A. fasciata. AfSPL14 was predominantly expressed in the young vegetative organs of adult plants. The expression of AfSPL14 could be upregulated within 1 h by exogenous ethephon treatment. The constitutive expression of AfSPL14 in Arabidopsis thaliana caused early flowering and variations in plant architecture, including smaller rosette leaves and thicker and increased numbers of main inflorescences. Our findings suggest that AfSPL14 may help facilitate the molecular breeding of A. fasciata, other ornamental and edible bromeliads (e.g., pineapple), and even cereal crops.

An arboreal spider protects its offspring by diving into the water of tank bromeliads.

Cupiennius salei (Ctenidae) individuals frequently live in association with tank bromeliads, including Aechmea bracteata, in Quintana Roo (Mexico). Whereas C. salei females without egg sacs hunt over their entire host plant, females carrying egg sacs settle above the A. bracteata reservoirs they have partially sealed with silk. There they avoid predators that use sight to detect their prey, as is known for many bird species. Furthermore, if a danger is more acute, these females dive with their egg sacs into the bromeliad reservoir. An experiment showed that this is not the case for males or females without egg sacs. In addition to the likely abundance of prey found therein, the potential of diving into the tank to protect offspring may explain the close association of this spider with bromeliads. These results show that, although arboreal, C. salei evolved a protective behavior using the water of tank bromeliads to protect offspring.

Orchid seed removal by ants in Neotropical ant-gardens.

Most plants that inhabit ant-gardens (AGs) are cultivated by the ants. Some orchids occur in AGs; however, it is not known whether their seeds are dispersed by AG ants because most orchid seeds are tiny and dispersed by wind. We performed in situ seed removal experiments, in which we simultaneously provided Azteca gnava ants with seeds of three AG orchid species and three other AG epiphyte species (Bromeliaceae, Cactaceae and Gesneriaceae), as well as the non-AG orchid Catasetum integerrimum. The seeds most removed were those of the bromeliad Aechmea tillandsioides and the gesneriad Codonanthe uleana, while seeds of AG orchids Coryanthes picturata, Epidendrum flexuosum and Epidendrum pachyrachis were less removed. The non-AG orchid was not removed. Removal values were positively correlated with the frequency of the AG epiphytes in the AGs, and seeds of AG orchids were larger than those of non-AG orchids, which should favour myrmecochory. Our data show that Azt. gnava ants discriminate and preferentially remove seeds of the AG epiphytes. We report for the first time the removal of AG orchid seeds by AG ants in Neotropical AGs.

Pollen morphology and viability in Bromeliaceae

ABSTRACT Pollen morphology characterization is important in taxonomy, conservation and plant breeding, and pollen viability studies can support breeding programs. This study investigated pollen morphology and male fertility in 18 species of Bromeliaceae with ornamental potential. For morphological characterization, pollen grains were acetolyzed and characterization of exine was done using scanning and transmission electron microscopy. Pollen viability was investigated by in vitro germination and histochemical tests. Species belonging to Aechmea and Ananas genera presented medium size pollen, except for Ae. fasciata, with large pollen. Al. nahoumii, P. sagenarius and the Vriesea species analyzed showed large pollen, except for V. carinata, with very large pollen. Pollen of Aechmea, Ananas and P. sagenarius presented bilateral symmetry, diporate, exine varying from tectate to semitectate. Al. nahoumii and Vriesea species presented pollen with bilateral symmetry, monocolpate; exine was semitectate, reticulate and heterobrochate. Germination percentage and tube growth were greater in SM and BKM media. Histochemical tests showed pollen viability above 70% for all species, except for Ananas sp. (40%). Pollen morphology is important for the identification of species, especially in this family, which contains a large number of species. High rates of viability favor fertilization and seed production, essential for efficient hybrid production and conservation.

The influence of light, substrate and seed origin on the germination and establishment of an ant-garden bromeliad.

Plant germination and development depend upon a seed's successful dispersal into a suitable habitat and its ability to grow and survive within the surrounding biotic and abiotic environment. The seeds of Aechmea mertensii, a tank-bromeliad species, are dispersed by either Camponotus femoratus or Neoponera goeldii, two ant species that initiate ant gardens (AGs). These two mutualistic ant species influence the vegetative and reproductive traits of the bromeliad through their divergent ecological preferences (i.e. light and substrate). We hypothesised that the seeds dispersed by these two ant species have underlying genetic differences affecting germination, growth and survival of A. mertensii seedlings in different ways. To test this, we used an experimental approach consisting of sowing seeds of A. mertensii: (i) taken from the two AG-ant associations (i.e. seed origin), (ii) in two contrasting light conditions, and (iii) on three different substrates. Light and substrate had significant effects on germination, survival and on eight key leaf traits reflecting plant performance. Seed origin had a significant effect only on germination and on two leaf traits (total dry mass and relative growth rate). Overall, this bromeliad performs better (i.e. high growth and survival rates) when growing both in the shade and in the carton nest developed by C. femoratus ants. These results suggest that the plasticity of the tank bromeliad A. mertensii is mainly due to environment but also to genetic differences related to seed origin, as some traits are heritable. Thus, these two ant species may play contrasting roles in shaping plant evolution and speciation.

Heterotrophic flagellates (Amorpha and Diaphoretiches) in phytotelmata bromeliad (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.

AfAP2-1, An Age-Dependent Gene of Aechmea fasciata, Responds to Exogenous Ethylene Treatment.

The Bromeliaceae family is one of the most morphologically diverse families with a pantropical distribution. To schedule an appropriate flowering time for bromeliads, ethylene is commonly used to initiate flower development in adult plants. However, the mechanism by which ethylene induces flowering in adult bromeliads remains unknown. Here, we identified an APETALA2 (AP2)-like gene, AfAP2-1, in Aechmea fasciata. AfAP2-1 contains two AP2 domains and is a nuclear-localized protein. It functions as a transcriptional activator, and the activation domain is located in the C-terminal region. The expression level of AfAP2-1 is higher in juvenile plants than in adult plants, and the AfAP2-1 transcript level was rapidly and transiently reduced in plants treated with exogenous ethylene. Overexpression of AfAP2-1 in Arabidopsis thaliana results in an extremely delayed flowering phenotype. These results suggested that AfAP2-1 responds to ethylene and is a putative age-dependent flowering regulator in A. fasciata.

Diversification of Bromelioideae (Bromeliaceae) in the Brazilian Atlantic rainforest: A case study in Aechmea subgenus Ortgiesia.

Aechmea subgenus Ortgiesia comprises ca. 20 species distributed in Brazil, Argentina, Paraguay, and Uruguay, with a center of diversity in the Brazilian Atlantic rainforest. We examined interspecific relationships of Ortgiesia based on Amplified Fragment Length Polymorphisms (AFLP). Ninety-six accessions belonging to 14 species of Ortgiesia were sampled, and genotyped with 11 AFLP primer combinations. The neighbor joining (NJ) tree depicted two main genetic groups within Aechmea subgenus Ortgiesia, and four subgroups. The NJ tree showed short internal branches, indicating an overall shallow genetic divergence among Ortgiesia species as expected for the recently radiated subfamily Bromelioideae. Our results suggest that hybridization and/or incomplete lineage sorting may have hampered the reconstruction of interspecific relationships in Aechmea subgenus Ortgiesia. The mapping of petal color (yellow, blue, pink, or white), inflorescence type (simple or compound), and inflorescence shape (ellipsoid, subcylindric, cylindric, or pyramidal) against the NJ tree indicated that these characters are of limited taxonomic use in Aechmea subgenus Ortgiesia due to homoplasy. An analysis of the current distribution of Ortgiesia identified the southern region of the Brazilian Atlantic rainforest, between latitudes of 26° and 27°S, as the center of diversity for the subgenus.

Tank bromeliads as natural microcosms: a facultative association with ants influences the aquatic invertebrate community structure.

Many tank bromeliads have facultative relationships with ants as is the case in French Guiana between Aechmea aquilega (Salib.) Griseb. and the trap-jaw ant, Odontomachus haematodus Linnaeus. Using a redundancy analysis, we determined that the presence of O. haematodus colonies is accompanied by a greater quantity of fine particulate organic matter in the water likely due to their wastes. This increase in nutrient availability is significantly correlated with an increase in the abundance of some detritivorous taxa, suggesting a positive bottom-up influence on the aquatic macroinvertebrate communities living in the A. aquilega wells. On the other hand, the abundance of top predators is negatively affected by a lower number of available wells due to ant constructions for nesting, releasing a top-down pressure that could also favor lower trophic levels.

The choice of bromeliads as a microhabitat by Scinax argyreornatus (Anura, Hylidae) / A escolha de bromélias, como micro-habitat, por Scinax argyreornatus (Anura, Hylidae)

The association of anurans to bromeliads presents different degrees of interaction such as: eventual, obligatory and bromeligen. The frog species Scinax argyreornatus shows a regular association with these plants. The goal of this study is to characterise the degree of association between the frog S. argyreornatus to different species of bromeliads. We identified which species of bromeliad is regularly associated with S. argyreornatus and recognised which factors interfere with this association preference. We analysed the Concentration of Relative Dominance of frogs per bromeliad species. As possible criteria for frog association preference to different bromeliads species we established the analysis of leaves number, length and width, number of leaf axils, stored water in the axils, pH and relative humidity, among other organographic components. Our observations were analyzed by ANOVA followed by the Tukey test. We also evaluated the preference for association by the constancy of Bodenheimer. The correlation matrix indicated that the relative humidity is the factor responsible for the frog-bromeliads association, except for Aechmea sp.. However Aechmea sp. was the species with greater constancy of occupation followed by Quesnelia arvensis and Neoregelia johannis. According to our statistical results, Aechmea sp. and Q. arvensis are not different regarding organographic parameters, but differ from N. johannis. Our observations suggest that the bromeliads organographic structure and the relative humidity are key conditions which influence the preferences of S. argyreornatus to bromeliad species, while the other features showed no correlation.

A associação dos anuros às bromeliáceas pode apresentar diferentes graus de interação, como: bromelículas eventuais, bromelículas obrigatórios e bromelígenas. Scinax argyreornatus apresenta uma associação frequente a essas plantas. Propõe-se, neste estudo, qualificar esse grau de associação, buscando identificar qual espécie de bromélia é mais ocupada, reconhecendo os fatores que interferem nessa escolha de ocupação. Analisou-se a Concentração de Dominância Relativa dos anuros por espécie de bromélia, sendo considerados como prováveis critérios de escolha: número, largura e comprimento das folhas, número de axilas foliares, volume de água acumulado, pH e umidade relativa, entre outros componentes organográficos, que foram submetidos à ANOVA e, sempre que observadas diferenças significativas, ao teste de Tukey. Avaliou-se também a escolha de ocupação pela constância de Bodenheimer. A matriz de correlação apontou a UR% como o fator responsável pela ocorrência do animal nas bromélias, exceto para Aechmea sp.; entretanto, esta foi a planta com maior Constância de ocupação, seguida por Quesnelia arvensis e Neoregelia johannis. Segundo a ANOVA, Aechmea sp. e Q. arvensis não apresentam diferenças entre si do ponto de vista organográfico, mas diferem de N. johannis. Foi possível inferir que a estrutura organográfica da planta e a UR% são as condições que interferem na escolha de ocupação das bromélias por S. argyreornatus, enquanto as outras características não demonstraram nenhuma correlação.

Aechmea rodriguesiana (L. B. Sm.) L. B. Sm. (Bromeliaceae) uma espécie endêmica da Amazônia brasileira / Aechmea rodriguesiana (L. B. Sm.) L. B. Sm. (Bromeliaceae), an endemic species of the Brazilian Amazon

Aechmea subgênero Chevaliera (Gaudich. ex Beer) Baker está representado na Amazônia brasileira pelas espécies A. fernandae (E. Morren) Baker e A. rodriguesiana (L. B. Sm.) L. B. Sm., sendo a última restrita para esta região. A. rodriguesiana se caracteriza pelas flores dispostas em racemo de espigas, com brácteas florais ovais, margens inteiras, envolvendo o ovário e pelas pétalas alvas e cuculadas. O presente trabalho apresenta a complementação da descrição e ilustrações desta espécie. São apresentados dados de distribuição geográfica, hábitats e fenológicos.

Aechmea subgenus Chevaliera (Gaudich. ex Beer) Baker, is represented in the Brazilian Amazon by two species: A. fernandae (E. Morren) Baker and A. rodriguesiana (L. B. Sm.) L. B. Sm., the latter being restricted to this region. A. rodriguesiana is characterized by flowers arranged on racemes of spikes, oval floral bracts with entire margins that completely surround the ovary, and by cuculate white petals. The present work has as main goal to complement the description and illustration of this species, exclusive to the Brazilian Amazon, allowing its recognition and conservation. Data on geographical distribution, habitat, and phenology are presented.