[Anopheles of the subspecies Kerteszia in relation to Bromeliaceae distribution in forest communities of the Brusque region, State of Santa Catarina].
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The crude methanolic extract of the aerial parts of Tillandsiastreptocarpa was investigated for their acute toxicity and antioedematogenic, antioxidant and antimicrobial activities. Also, the antioedematogenic activity of the hexane fraction resulting from the partition of the crude methanolic extract was evaluated. The methanolic extract and the hexane fraction showed significant (P < 0.05) inhibition of ear oedema, observed at 2 mg/ear in the croton oil-induced mice ear oedema test. In the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging test, a high reactivity and potent antioxidant effect (IC(50) = 0.0056%, w/v) were observed for the methanolic extract. The antimicrobial activity assay showed that the crude methanolic extract was inactive toward Escherichiacoli, Staphylococcusaureus, Pseudomonasaeruginosa, Bacillussubtilis, Candidaalbicans, C. parapsilosis, C. krusei and C. tropicalis (MIC > 500 microg/ml). The methanolic extract showed no toxic effect on mice at a single dose of 2000 mg/kg (p.o). Common side effects including mild diarrhoea, loss of weight and depression were not recorded. The compounds cycloartenol, 4',5-dihydroxy-3',7-dimethoxyflavanone and a mixture of the steroids stigmasterol, beta-sitosterol and campesterol, were isolated from the hexane fraction and identified by spectroscopic methods.
We examined the relationships between H2O and CO2 gas exchange parameters and leaf trichome cover in 12 species of Tillandsia that exhibit a wide range in trichome size and trichome cover. Previous investigations have hypothesized that trichomes function to enhance boundary layers around Tillandsioid leaves thereby buffering the evaporative demand of the atmosphere and retarding transpirational water loss. Data presented herein suggest that trichome-enhanced boundary layers have negligible effects on Tillandsia gas exchange, as indicated by the lack of statistically significant relationships in regression analyses of gas exchange parameters and trichome cover. We calculated trichome and leaf boundary layer components, and their associated effects on H2O and CO2 gas exchange. The results further indicate trichome-enhanced boundary layers do not significantly reduce transpirational water loss. We conclude that although the trichomes undoubtedly increase the thickness of the boundary layer, the increase due to Tillandsioid trichomes is inconsequential in terms of whole leaf boundary layers, and any associated reduction in transpirational water loss is also negligible within the whole plant gas exchange pathway.
Epiphytes absorb water and nutrients from the atmosphere through precipitation and dry deposition and from their hosts through stemflow and throughfall. These commensals have been used as biological indicators or monitors of air quality. To measure temporal changes in Spanish moss (Tillandsia usneoides) mineral concentrations, we revisited sites in Central Florida where this epiphyte was collected and analyzed in 1973/1974. After 24-25 years, using comparable methods, concentrations of Ca, Mg, K and Cu decreased in the tissue samples while Fe increased. These declines in base cations corresponded to global atmospheric decreases. In the earlier study, patterns of elemental concentrations in Spanish moss corresponded to the host tree categories primarily reflecting a P gradient that increased from pine (Pinus spp.) to cypress (Taxodium spp.) to hardwood (e.g. Quercus spp.) hosts. Such host-specific associations were mostly absent from the recent study, suggesting that epiphytic preferences based on the chemistry of phorophyte leachates have become less important in this region, perhaps, resulting from local (suburbanization) or regional (atmospheric composition) changes.
Bromelia antiacantha flowered from December to February and during this period the central leaves and bracts displayed a bright red colour. The inflorescence bears 150-350 flowers, with 10-35 flowers opening per day over 4-5 days. The flowers are dark magenta coloured with white margins, tubular-shaped with a wide opening, and their stigma is situated below the anthers. Anthesis began around 4:00 h and flowers lasted approximately 15 h. The highest nectar volume and sugar concentration occurred between 4:00-6:00 h; after this period, both decreased throughout the day. B. antiacantha is partially self-incompatible, non-autogamous, and therefore, pollinator dependent. The hummingbirds Thalurania glaucopis, Amazilia fimbriata, and Ramphodon naevius were its most frequent pollinators (55% of the visits), visiting flowers mainly in the afternoon. The scattered distribution of B. antiacantha promoted trap-lining behaviour of the hummingbirds, which favoured fruit set through xenogamy. Corolla colour, wide flower opening, sweet odour and concentrated nectar early in the day favoured bee visitation. Of the 38 % of bee visits, 96% were made by Bombus morio, mainly in the morning and their behaviour promoted self-pollination. The bee Trigona spinipes frequently acted as a pollen and nectar thief early in the morning, excluding most of the hummingbirds. Bromelia antiacantha has ornithophilous and melittophilous features, and despite being pollinated by two kinds of agents, its reproductive success depends on a given set of circumstances.
In an effort to understand the mechanisms that sustain rootless atmospheric plants, the modulation of Crassulacean acid metabolism (CAM) in response to variations in irradiance and water supply was investigated in the epiphyte Tillandsia usneoides. Plants were acclimated to three light regimes, i.e. high, intermediate and low, with integrated photon flux densities (PFD) of 14.40, 8.64 and 4.32 mol m-2 d-1 equivalent to an instantaneous PFD of 200, 100, and 50 mumol m-2 s-1, respectively. Daily watering was then withdrawn from half of the plants at each PFD for 7 d prior to sampling. In response to the three PFD treatments, chlorophyll content increased in plants acclimated to lower irradiances. Light response curves using non-invasive measurements of chlorophyll fluorescence demonstrated that photosystem II efficiency (phi PSII) was maintained in high PFD acclimated plants, as they exhibited a larger capacity for non-photochemical dissipation (NPQ) of excess light energy than low PFD acclimated plants. Net CO2 uptake increased in response to higher PFD, reflecting enhanced carboxylation capacity in terms of phosphoenolpyruvate carboxylase (PEPc) and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activities. After water was withdrawn, nocturnal net CO2 uptake and accumulated levels of acidity declined in all PFD treatments, concomitant with increased respiratory recycling of malate. Examining the strategies employed by epiphytes such as T. usneodies to tolerate extreme light and water regimes has demonstrated the importance of physiological mechanisms that allow flexible carboxylation capacity and continued carbon cycling to maintain photosynthetic integrity.
BACKGROUND AND AIMS: The monoecious, bird-pollinated epiphytic Tillandsia achyrostachys E. Morr. ex Baker var. achyrostachys is an endemic bromeliad of the tropical dry forests of Mexico with clonal growth. In the Sierra de Huautla Natural Reserve this species shows a host preference for Bursera copallifera (Sessé & Moc ex. DC) Bullock. As a result of deforestation in the study area, B. copallifera has become a rare tree species in the remaining forest patches. This human-induced disturbance has directly affected the population densities of T. achyrostachys. In this study the genetic consequences of habitat fragmentation were assessed by comparing the genetic diversity, gene flow and genetic differentiation in six populations of T. achyrostachys in the Sierra de Huautla Natural Reserve, Mexico. METHODS: Allozyme electrophoresis of sixteen loci (eleven polymorphic and five monomorphic) were used. The data were analysed with standard statistical approximations for obtaining diversity, genetic structure and gene flow. KEY RESULTS: Genetic diversity and allelic richness were: HE = 0.21 +/- 0.02, A = 1.86 +/- 0.08, respectively. F-statistics revealed a deficiency of heterozygous plants in all populations (Fit = 0.65 +/- 0.02 and Fis = 0.43 +/- 0.06). Significant genetic differentiation between populations was detected (Fst = 0.39 +/- 0.07). Average gene flow between pairs of populations was relatively low and had high variation (Nm = 0.46 +/- 0.21), which denotes a pattern of isolation by distance. The genetic structure of populations of T. achyrostachys suggests that habitat fragmentation has reduced allelic richness and genetic diversity, and increased significant genetic differentiation (by approx. 40 %) between populations. CONCLUSIONS: The F-statistic values (>0) and the level of gene flow found suggest that habitat fragmentation has broken up the former population structure. In this context, it is proposed that the host trees of T. achyrostachys should be considered as a conservation priority, since they represent the limiting factor to bromeliad population growth and connectivity.
Spanish moss (Tillandsia usneoides L.) was collected in South Carolina, maintained in a greenhouse, then exposed to five levels of photosynthetic photon flux density (PPFD) for 3 weeks. Following this treatment, plants were sampled for chlorophyll concentrations, nocturnal acid accumulations, and photosynthetic responses to subsequent exposure at a range of PPFD. No acclimation to PPFD was observed; all plants exhibited similar patterns of nocturnal CO(2) uptake and acid accumulation regardless of initial PPFD treatment. These patterns revealed that at a PPFD level of approximately 200 micromoles per square meter per second (daytime integrated PPFD of 10 moles per square meter per day), CAM saturated or, in low-PPFD plants, was optimal. The results of this study indicate that adaptation to high PPFD is not necessarily a requirement of CAM.
The properties of two cysteine peptidases (macrodontain I and II) isolated from fruits of Pseudananas macrodontes have been compared. The enzymes showed optimum pH ranges near neutrality and were inhibited by E-64 and other cysteine peptidase inhibitors. Molecular masses were 23459 and 23703 kDa, the isoelectric points were 6.1 and 5.9, and the Km values were 13.4 and 8.9 microM (Bz-Phe-Val-Arg-AMC) for macrodontain I and II, respectively. N-alpha-CBZ-L-amino acid p-nitrophenyl esters were tested for both enzymes. The N-terminal sequences of both proteases differed slightly and showed high sequence similarity to other pineapple stem-derived cysteine endopeptidases.
South American inselbergs constitute singular and fragmented habitats in the tropical rain forest. Pitcairnia geyskesii is restricted to these habitats and exhibits both sexual and asexual reproduction. The genetic structure of populations on three inselbergs in French Guiana is examined by analysis of ten isozyme loci. All analyzed populations show high levels of genetic variation. On average, 63.3% of loci per population were polymorphic, with a mean number of 2.21 alleles per polymorphic locus, and mean observed and expected heterozygosities of 0.185 and 0.183, respectively. The analyses of genetic variability displayed at different levels (inselbergs, subpopulations, and mats) give different but complementary information. A significant multilocus disequilibrium was detected in one subpopulation, whereas none was observed within the whole populations sampled on the three inselbergs. Tests on spatial genetic structure indicate a patchy distribution of genotypes on two inselbergs. The data give some insights on the reproductive behavior of P. geyskesii. (1) Efficient sexual reproduction leads to seed recruitment at the level of the inselberg. (2) Both clonality and seed recruitment occur within mats. (3) Vegetative spread by fragmentation is involved in the establishment of new mats. There is substantial differentiation (F(ST) = 0.322) and low gene flow among inselbergs (Nm = 0.234). High genetic diversity within inselbergs appears as a consequence of the association of genet longevity induced by clonal replication and recruitment of new genets produced by sexual reproduction.
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Phylogenetic relationships of the five families of the order Commelinales remain an area of deep uncertainty in higher-level monocot systematics, despite intensive morphological and anatomical study. To test the monophyly of the Commelinales and the subclass Commelinidae, evaluate their relationships, and analyze evolutionary trends in their morphology, ecology, and biogeography, we conducted parsimony analyses on 95 rbcL sequences representing 17 taxa of Commelinales, 16 taxa of other Commelinidae, and 63 taxa from Arecidae, Liliidae, and Zingiberidae. Commelinales is polyphyletic and Commelinidae paraphyletic, with Eriocaulaceae and Xyridaceae sister to Poaceae and its relatives, Rapateaceae sister to Bromeliaceae and Mayacaceae, and Commelinaceae sister to Philydrales and allies. Thurnia is sister to Prionium at the base of Cyperaceae-Juncaceae; only 1 of Cronquist's multifamily commelinoid orders is diagnosed as monophyletic. We propose a revised Commelinidae, incorporating 4 revised superorders (Bromelianae, Commelinanae, Dasypogonanae, Arecanae) and 10 orders ((Poales, Eriocaulales, Cyperales, Typhales, Bromeliales), (Commelinales, Philydrales, Zingiberales), (Dasypogonales), (Arecales)). Morphological and anatomical characters used to define the original Commelinales and Commelinidae appear to be plesiomorphic or to reflect convergence or recurrent mutation; several characters supporting our revised classification are anatomical traits that seem relatively insulated from environmental selection pressures. The Commelinidae distal to the Arecales arose in South America, with amphiatlantic Bromeliaceae-Mayacaceae-Rapateaceae originating in the Guayana Shield. Ecological diversification involved the repeated invasion of shady, infertile, or arid microsites. The numbers of species in families of the revised Commelinidae are related partly to the extent of adaptive radiation in those families, but seem more strongly related to nonadaptive features promoting speciation, such as restricted seed dispersal (especially in forest interior groups with fleshy fruits), polyploidy, aneuploidy, and apomixis. Species diversity is unrelated to the rate/amount of rbcL sequence evolution.
Unripe fruit extracts of Bromelia balansae Mez (Bromeliaceae), whose principal endopeptidase is balansain I (isolated for anion exchange chromatography: pI = 5.45, molecular weight = 23192), exhibit a pH profile with a maximum activity around pH 9.0 and are inhibited only by cysteine peptidases inhibitors. The alanine and glutamine derivatives of N-alpha-carbobenzoxy-L-amino acid p-nitrophenyl esters were strongly preferred by the enzyme. Enzymatic hydrolysis of milk and soy proteins yield characteristic patterns at pH 9.0. The N-terminal sequence showed a very high homology (85-90%) with other known Bromeliaceae endopeptidases.
OBJECTIVE: Aedes albopictus populations can breed in several kinds of containers, and its presence has also been reported in Bromeliaceae. The purpose of this study was to evaluate the epidemiological importance of the Bromeliaceae plants as potential breeding sites of Aedes albopictus and to document the associated Culicidae entomofauna found in this micro-habitat. METHODS: Collections of Culicidae larvae were carried out fortnightly in aquatic content of bromeliads during 1998 and 1999. Collections took place in urban and periurban areas of Ilhabela island and periurban area of Ilha Comprida island, Brazil. RESULTS: A total of 26,647 Culicidae larvae were collected at both study sites, 14,575 in the urban area and 10,987 in the periurban area of Ilhabela and the remaining 1,085 in the periurban area of Ilha Comprida. There was no statistical difference between the amount of larvae collected in urban and periurban areas of Ilhabela. Regarding the Ae. albopictus, there was found a higher frequency and amount of larvae in the urban area of Ilhabela, followed by the periurban area in the same site, whereas in the periurban area of Ilha Comprida, its presence was considered accidental, since it was reported only in the first three months. CONCLUSIONS: The results show that bromeliads, largely used in landscaping, may contribute to the spread of Ae. albopictus. The presence of this species in domesticated and domiciled bromeliads allows us to suggest that the Culicidae larva is part of the regional fauna and facilitate the contact between humans and etiological agents of the natural ecosystem.
The occurrence of crassulacean acid metabolism (CAM) in the epiphyte community of a lowland forest of the Atlantic slope of Panama was investigated. I hypothesized that CAM is mostly found in orchids, of which many species are relatively small and/or rare. Thus, the relative proportion of species with CAM should not be a good indicator for the prevalence of this photosynthetic pathway in a community when expressed on an individual or a biomass basis. In 0.4 ha of forest, 103 species of vascular epiphytes with 13,099 individuals were found. As judged from the C isotope ratios and the absence of Kranz anatomy, CAM was detected in 20 species (19.4% of the total), which were members of the families Orchidaceae, Bromeliaceae, and Cactaceae. As predicted, the contribution of CAM epiphytes to the total number of individuals and to total biomass (69.6 kg ha(-1)) was considerably lower (3.6% or 466 individuals and, respectively, 3.0% or 2.1 kg ha(-1)).
A novel agglutinin gene was cloned from Arisaema lobatum using SMART RACE-PCR technology. The full-length cDNA of Arisaema lobatum agglutinin (ala) was 1078 bp and contained a 774 bp open reading frame encoding a lectin precursor (proproprotein) of 258 amino acid residues with a 23 aa signal peptide. ALA contained three mannose-binding sites (QXDXNXVXY) with two-conserved domains of 45% identity, ALA-DOM1 and ALA-DOM2. The three-dimensional structure of ALA was very similar to that of GNA (Galanthus nivalis agglutinin). ALA shared varying identities, ranging from 40% to 85%, with mannose-binding lectins from other species of plant families, such as Araceae, Alliaceae, Iridaceae, Lillaceae, Amaryllidaceae and Bromeliaceae. Genomic sequence of ala was also cloned using genomic walker technology, and it was found to contain three putative TATA boxes and eight possible CAAT boxes in the 5'-flanking region. No intron was found within the region of genomic sequence. Southern blot analysis indicated that the ala belonged to a multi-copy gene family. Expression pattern analysis revealed that the ala preferentially expressed in the tissues with the higher expression being found in spadix, bud, leaf, spathe and tuber. The cloning of the ala gene not only provides a basis for further investigation of its structure, expression and regulation mechanism, but also enables us to test its potential role in controlling pests and fungal diseases by transferring the gene into plants in the future.
We evaluated the indoor atmospheric Hg contamination in gold trade shops in two Brazilian cities of the Legal Amazon area using the Spanish moss (Tillandsia usneoides, Bromeliaceae) as a sentinel species. Plants inside plastic cages were exposed to a controlled atmosphere to evaluate the rate of Hg retention over time and then distributed in several stores with different characteristics to enable a relative comparison. Hg concentrations were determined by cold vapor atomic absorption spectrophotometry. Plants exposed in active stores with good air circulation exhibited lower levels. Ex-gold trade shops that were kept closed for long periods exhibited higher values. Stores that have been restored before being transformed into new businesses exhibited lower values than nonrestored ones. Direct measurements suggest that indoor Hg air concentrations were below the threshold limit recommended by the World Health Organization to occupational exposure; nevertheless, restoring ex-gold trade shops could ensure a healthier working environment.