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Miriam Dupas Hubinger - One of the best experts on this subject based on the ideXlab platform.
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anthocyanins from jussara Euterpe Edulis martius extract carried by calcium alginate beads pre prepared using ionic gelation
Powder Technology, 2019Co-Authors: Ana Gabriela Da Silva Carvalho, Mario Roberto Marostica, Mariana T C Machado, Helena Dias De Freitas Queiroz Barros, Cinthia Bau Betim Cazarin, Miriam Dupas HubingerAbstract:Abstract In order to take advantage of the functional properties of the jussara (Euterpe Edulis Martius) extract, this study aimed at producing alginate hydrogel beads by ionic gelation process to carry jussara extract, increase its stability and to protect the anthocyanins from environmental conditions that interfere in stability and color of these compounds, such as the pH of the medium. Anthocyanins encapsulation from extract occurred by adsorption technique using blank alginate beads. Ionic gelation method was combined with complexation process using chitosan, whey protein concentrate or gelatin. Complexation technique using cationic polymers was effective in protecting these pigments during refrigerated storage. Gel strength of the hydrogel beads and anthocyanins retention was influenced by zeta potential and apparent viscosity of the materials used in the coating process. Chitosan presented higher zeta potential (+57.1 ± 2.0 mV) and apparent viscosity (0.013 ± 0.000 Pa.s) values and the beads coated with this material showed higher monomeric anthocyanins retention (8.4 ± 0.2 mg of cyanidin 3-glucoside equivalent/g of dry bead) than those coated with whey protein concentrate and gelatin (6.6 ± 0.3 and 5.2 ± 0.4 mg of cyanidin 3-glucoside equivalent/g of dry bead, respectively). Ionic gelation encapsulation process led to the formation of hydrogel beads containing anthocyanins, thus enabling the release profile of the compounds at specific pH conditions, such as the intestinal fluid.
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influence of nanofiltration membrane features on enrichment of jussara ethanolic extract Euterpe Edulis in anthocyanins
Journal of Food Engineering, 2018Co-Authors: Glaucia S Vieira, Francys K V Moreira, Regiane L S Matsumoto, Mariano Michelon, Francisco Maugeri Filho, Miriam Dupas HubingerAbstract:Abstract Anthocyanins were concentrated from ethanolic jussara (Euterpe Edulis) extract by nanofiltration. Six commercial flat-sheet membranes with nominal molecular weight cut-off ranging from 150 to 1000 g mol−1 (NF270 and NF90 from Filmtec Dow, NP010 and NP030 from Microdyn Nadir and Desal 5-DK and Desal 5-DL from GE Osmonics) were characterized in terms of their textural properties, surface morphology and further evaluated for jussara extract nanofiltration performance. Nanofiltration trials were conducted on a stainless steel stirred dead-end cell, in which permeate fluxes were recorded by keeping operational conditions constant at 25 bar and 25 °C. N2 adsorption isotherms and atomic force microscopy images revealed a nanoporous bulk for all membranes. Changes in roughness and contact angle of membranes were observed to occur after nanofiltration trials. The Desal 5-DK membrane showed the highest efficiency for jussara extract nanofiltration due to its highest flux and smallest flux decline, in addition to the highest anthocyanins retention capacity in relation to the other commercial nanofiltration membranes.
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determination of anthocyanins and non anthocyanin polyphenols by ultra performance liquid chromatography electrospray ionization mass spectrometry uplc esi ms in jussara Euterpe Edulis extracts
Journal of Food Science and Technology-mysore, 2017Co-Authors: Glaucia S Vieira, Mariana T C Machado, Vanessa Silva, Anna S F Marques, Miriam Dupas HubingerAbstract:This work aimed to propose two analytical methods for the quantitative and qualitative analysis of major anthocyanins and non-anthocyanin phenolic compounds in jussara (Euterpe Edulis) extracts, using ultra performance liquid chromatography-mass spectrometry. These methods were evaluated for selectivity, precision, linearity, detection and quantification limits. The complete separation of 5 anthocyanins and 22 non-anthocyanins polyphenols was achieved in 4.5 and 7 min, respectively. Limits of detection ranged from 0.55 to 9.24 µg/L, with relative standard deviation for concentration up to 7.0%. In jussara extract, 13 of the 27 analytes were characterized. The dominant compound was cyanidin-3-O-rutinoside, representing about 73% of the total phenolic compounds content (approximately 23 mg/g of extract in dry weight). Other phenolic compounds found in the extract were: cyanidin-3-O-glucoside, pelargonidin-3-O-glucoside, quercetin, rutin, myricetin, kaempferol, kaempferol-3-O-rutinoside, luteolin, apigenin, catechin, ellagic acid and 4,5-dicaffeoylquinic acid.
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physical properties and morphology of spray dried microparticles containing anthocyanins of jussara Euterpe Edulis martius extract
Powder Technology, 2016Co-Authors: Ana Gabriela Da Silva Carvalho, Mariana T C Machado, Vanessa Silva, Adilson Sartoratto, Rodney Alexandre Ferreira Rodrigues, Miriam Dupas HubingerAbstract:Abstract Anthocyanins are sensitive compounds and easily degradable when exposed to light, oxygen and pH values higher than 7. In this context, to better take advantage of the functional properties and to increase the stability of these pigments, this work aimed to obtain extracts from jussara (Euterpe Edulis Martius) pulp and to produce spray dried microparticles. Maltodextrin with different dextrose equivalent values (10, 20 and 30 DE), gum Arabic and the combination of the maltodextrin 10 DE with gum Arabic (proportions 25:75; 50:50 and 75:25) were evaluated as carrier agents. Microparticles were characterized in relation to the moisture content, water activity, hygroscopicity, glass transition temperature, particle size distribution, color, anthocyanin content and profile, antioxidant capacity and microstructure. Microparticles showed high anthocyanin retention, above 88%. Anthocyanin profiles were similar to the microparticles and jussara extract and two anthocyanins identified were cyanidin 3-rutinoside and cyanidin 3-glucoside. Carrier agents influenced on the microparticles characteristics; maltodextrin 30 DE presented higher hygroscopicity and the lowest glass transition temperature. Microparticles produced with maltodextrin 10, 20 and 30 DE have shown smoother spherical surface than particles constituted with gum Arabic. Homogeneous distribution of anthocyanin in the particle structure was observed by confocal microscopy analysis.
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chemical and economic evaluation of natural antioxidant extracts obtained by ultrasound assisted and agitated bed extraction from jussara pulp Euterpe Edulis
Journal of Food Engineering, 2013Co-Authors: Glaucia S Vieira, Rodrigo N Cavalcanti, Angela M A Meireles, Miriam Dupas HubingerAbstract:Abstract This work aimed to evaluate the influence of ultrasonic and agitated bed extractions on the chemical composition and manufacturing costs of extracts obtained from jussara ( Euterpe Edulis ) pulp. The effects of extraction time (5–180 min), temperature (25–55 °C), ethanol concentration (0–90% in acidified water) and solvent/pulp ratio (5–30 mL/g) on the extraction yield, phenolic content, anthocyanin content, antioxidant capacity and manufacturing costs were assessed. The yields provided by the ultrasound-assisted and agitated bed extractions were not significantly different. The anthocyanins and phenolic compound yields were significantly affected by the extraction time, the ethanol concentration in water and the solvent/feed ratio, but not by the temperature. In general, the antioxidant capacity of the extracts displayed tendencies similar to the anthocyanin and phenolic compound yields. The production of crude extracts obtained by ultrasound and agitated bed extraction incurred greater manufacturing costs compared to the market prices of assai extracts.
Roseane Fett - One of the best experts on this subject based on the ideXlab platform.
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antioxidant and jucara fruits Euterpe Edulis martius potential applications in toxicology
2021Co-Authors: Mayara Schulz, Ana Carolina Oliveira Costa, Luciano Valdemiro Gonzaga, Roseane FettAbstract:Abstract Euterpe Edulis Martius species, popularly called jucara palm or “palmiteiro,” is a native to the Atlantic Rainforest biome and found mainly in the Southern and Southeastern Brazilian states. This palm produces globose fruits, which are violaceous purple in color when mature and usually used for pulp or juice production. These fruits and their products recently gained worldwide attention, mainly for their high nutritional value and antioxidant compounds. The concentrations of antioxidants such as phenolic compounds, especially anthocyanins, vitamin C, carotenoids, selenium, and manganese are generally higher in jucara fruits when compared to other berries. In this way, studies also report that the jucara fruits have a high activity of deactivation of radicals, ferric reducing power, as well as inhibition of β-carotene bleaching. Additionally, the antioxidant potential of these fruits is demonstrated in cellular models and the majority of the in vivo studies observed a decrease in markers of lipid peroxidation and enzymatic antioxidant activity, probably due to the ingestion of the antioxidants present in the jucara fruits. This chapter focuses on the antioxidant compounds in jucara fruits, as well as in vitro and in vivo studies on the antioxidant activity of these fruits.
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Juçara fruit (Euterpe Edulis Mart.): Sustainable exploitation of a source of bioactive compounds.
Food research international (Ottawa Ont.), 2016Co-Authors: Mayara Schulz, Ana Carolina Oliveira Costa, Graciele Da Silva Campelo Borges, Luciano Valdemiro Gonzaga, Roseane FettAbstract:Jucara (Euterpe Edulis Martius) is a palm tree widely distributed in the Atlantic Forest, which produces round fruits that recently gained worldwide attention, mainly for its resemblance to fruits of Euterpe oleracea and Euterpe precatoria Martius used to produce acai. Jucara fruits stand out for their high nutritional value, which contain different kinds of nutrients, including fatty acids, protein, fibers, minerals and vitamins, and bioactive compounds such as anthocyanins, non-anthocyanin flavonoids and phenolic acids, which are associated with potent biological activities. The main objective of this work is to present the available compositional data regarding jucara fruits to produce a comprehensive source of recent information on important chemical constituents and the potential health benefits of these fruits in reference to the species E. oleracea and E. precatoria. In addition, information on botanical aspects, production chain and markets are presented.
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protective effect of Euterpe Edulis m on vero cell culture and antioxidant evaluation based on phenolic composition using hplc esi ms ms
Food Research International, 2013Co-Authors: Graciele Da Silva Campelo Borges, Fernanda Archilla Jardini, Jorge Mancini Filho, Melina Heller, Ana Carolina Oliveira Costa, Gustavo Amadeu Micke, Luciano Valdemiro Gonzaga, Roseane FettAbstract:Abstract This article reports a study on the antioxidant activity of jucara (Euterpe Edulis M.) (defatted pulp and oil) and the cytoprotective effect in terms of oxidative damage induced by tert-butyl hydroperoxide (TBH) in a Vero cell culture. Simultaneously, HPLC–ESI-MS/MS was used to determine the phenolic composition of defatted pulp jucara extracts. The defatted pulp extract exhibited stronger free radical scavenging ability in 1,1-diphenyl-2-picrylhydrazyl (DPPH), ion ferric (FRAP) and β-carotene systems than the lipid extract. The predominance of phenolic acids (benzoic, caffeic, chlorogenic, ferulic, protocatechuic, syringic, vanillic and ρ-coumaric) and flavonols (quercetin and rutin) was observed in the extracts by direct infusion–ESI-MS/MS in negative ion mode. Jucara extracts (1.5, 4.5, 9 μg mL− 1) had a significant protective effect against TBH-induced oxidative stress in Vero cells compared to the gallic acid control. These results provide novel information on the jucara fruit (E. Edulis M.) regarding the relation between the phenolic compound composition and antioxidant and cytoprotective effects.
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chemical characterization bioactive compounds and antioxidant capacity of jussara Euterpe Edulis fruit from the atlantic forest in southern brazil
Food Research International, 2011Co-Authors: Graciele Da Silva Campelo Borges, Jorge Mancini Filho, Francilene Gracieli Kunradi Vieira, Luciano Valdemiro Gonzaga, Cristiane Copetti, Rui Carlos Zambiazi, Roseane FettAbstract:Abstract Samples of fruit from the jussara palm plant ( Euterpe Edulis ), collected in different regions of the state of Santa Catarina, Brazil, were analyzed for chemical composition, phenolic acids, anthocyanins, flavonoids and fatty acids profile. Results indicated that the jussara fruit has a high lipid content (18.45–44.08%), oleic acid (44.17–55.61%) and linoleic acid (18.19–25.36%) are the fatty acids found in the highest proportion, and other components were proteins (5.13–8.21%), ash (1.55–3.32%) and moisture (34.95–42.47%). Significant differences were found in the total phenolic, total monomeric anthocyanins and other flavonoids for the samples from the five cultivation regions. The fruit from region E harvested in summer, with high temperatures and medium altitudes, had the highest contents of total phenolics (2610.86 ± 3.89 mg 100 g −1 GAE) and monomeric anthocyanins (1080.54 ± 2.33 mg 100 g − 1 cy-3-glu). The phenolic compound included ferulic, gallic, hydroxybenzoic and p-coumaric acids, as well as catechin, epicatechin and quercetin. The results show promising perspectives for the exploitation of this tropical fruit with a chemical composition comprising considerable phenolic acids and flavonoids compounds and showing activity antioxidant.
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optimization of the extraction of flavanols and anthocyanins from the fruit pulp of Euterpe Edulis using the response surface methodology
Food Research International, 2011Co-Authors: Graciele Da Silva Campelo Borges, Francilene Gracieli Kunradi Vieira, Luciano Valdemiro Gonzaga, Cristiane Copetti, Roseane FettAbstract:Abstract The response surface methodology (RSM) was employed to optimize the ultrasound extraction of flavanols and anthocyanins from the pulp of jussara (Euterpe Edulis), using a second-order polynomial equation to describe the experimental data for total flavanol (TF), total phenolic (TP), and total monomeric anthocyanin (TMA) contents, as well as the total antioxidant activity (TAA). A central composite design with two-variables (extraction time and solid to liquid ratio) was then applied. The optimized conditions that maximized the yields of flavanol-enriched extract were a solvent methanol/0.1 M HCl, solid to liquid ratio of between 1:50 and 1:100 and extraction time of 15 min. For anthocyanin-enriched extracts the respective optimal parameters were a solvent methanol/1.5 M HCl, solid to liquid ratio of between 1:30 and 1:50 and extraction time of 24 h. The results showed good fits with the proposed model for both the flavanol-enriched extract (R2 = 0.94) and for the anthocyanin-enriched extract (R2 = 0.99).
S. Maldonado - One of the best experts on this subject based on the ideXlab platform.
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Storage lipids and proteins of Euterpe Edulis seeds
Biocell : official journal of the Sociedades Latinoamericanas de Microscopia Electronica ... et. al, 2009Co-Authors: V. Panza, V. Láinez, Dario Pighin, Ricardo J. Pollero, S. MaldonadoAbstract:Comparative studies on fatty acid and protein composition of the endosperm and embryo of palmito (Euterpe Edulis Martius) were conducted using gas-liquid chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. On a dry weight basis, the embryo contained extremely lower amounts of lipids and proteins than did the endosperm, which was associated with the scarce lipid and protein bodies previously reported in axis and cotyledon. The fatty acid composition also exhibited differences between both tissues: (I) the fatty acid diversity was greater in embryo than in endosperm; (II) embryo and endosperm contained predominantly linoleic, palmitic, oleic and stearic acids even though the relative values were different for each tissue. As compared to other palm species, the higher fatty acid unsaturation in Euterpe Edulis seed could be involved in the previously reported short longevity and recalcitrant behavior during storage. Proteins of both tissues were heterogeneous in molecular mass. Some proteins were tissue-specific, but other were common, among them a highly glycosylated protein which migrated at about 55 kDa. We hypothesize that the latter, also reported in all previously studied palm species, is one of the proteins characterizing the Arecaceae family.
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effects of desiccation on Euterpe Edulis martius seeds
Biocell, 2007Co-Authors: V. Panza, V. Láinez, S. Maldonado, Horacio MaroderAbstract:Information on desiccation sensitivity of Euterpe Edulis seeds under two drying rates is presented. The sensitivity was studied during the course of germination and normal germination. The water content was evaluated for both seeds and embryos. Results showed the following: (a) For both drying treatments and for both germination and normal germination, desiccation sensitivity values were higher for measurements based on the water content of the embryo than for those of the seed. (b) For both drying treatments, desiccation sensitivity were higher for normal germination than for germination based on both the embryo and seed water contents. (c) Under the slow drying treatment and for measurements based on the seed water content, critical water content was visible for normal germination but not for germination; (d) Critical water contents for germination and normal germination were more clearly established in the fast drying treatment than they were in the slow drying method based on both the embryo and seed water contents. Critical water contents were not associated with changes in electrolyte leakage, which suggests that conductivity is not a good indicator of physiological seed quality. From the beginning of both drying treatments, changes in nuclei and vacuoles were observed, but, when seed water content was reduced to below critical values, the cells became severely plasmolyzed, the vacuoles highly distorted, and the nuclei formed an almost homogeneous mass with the chromatin and the nucleoplasm, which suggests irreversible DNA damages. BIOCELL 2007, 31(3): 383-390 ISSN 0327 9545 PRINTED IN ARGENTINA
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Detection of dehydrin-like proteins in embryos and endosperm of mature Euterpe Edulis seeds
Protoplasma, 2007Co-Authors: V. Panza, A. J. Distéfano, P. Carjuzaa, V. Láinez, M. Del Vas, S. MaldonadoAbstract:Euterpe Edulis Martius, a tropical palm species characterized as highly recalcitrant, accumulated dehydrin proteins in both the endosperm and the embryo of the mature seed, as detected by Western blot analysis and immunogold electron microscopy. Three major bands at molecular masses of approximately 16, 18, and 24 kDa were identified in both samples analysed. Immunogold electron microscopy studies detected the presence of dehydrins in the embryo and endosperm. In both cases, dehydrins were immunolocalized in cytoplasm and chromatin. No labelling associated with either membranes or organelles was detected. It is known that dehydrins are produced as part of the developmental program of orthodox seeds and are also present in some recalcitrant seeds of temperate regions. The constitutive presence of dehydrins in embryos of extremely recalcitrant species of tropical origin has not been previously reported.
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seed structure and histochemistry in the palm Euterpe Edulis
Botanical Journal of the Linnean Society, 2004Co-Authors: V. Panza, V. Láinez, S. MaldonadoAbstract:The Euterpe Edulis embryo consists of a prominent single cotyledon, a very short radicle-hypocotyl axis and an epicotyl. The epicotyl is obliquely angled with respect to the cotyledon; consequently it corresponds to one of the two categories recognized for palm seeds by DeMason (1988). Parenchyma, protoderm and procambium can be distinguished on the basis of position and shape of their cells, which are highly vacuolated with one central vacuole and the cytoplasm restricted to a thin parietal layer. Initial cells from both apical meristems are also vacuolated but they have small vacuoles distributed around the nuclei. Silica occurs in cell walls of some protodermal cells. Raphides, silica bodies and tannins all occur occasionally in vacuoles, especially in the basal cotyledon region. Most embryo cells lack storage reserves and exhibit an active state, with numerous mitochondria, RER cisternae and Golgi apparatus, indicating a strategy of continuous development without the interposition, at maturity, of a dry state. The endosperm consists of living cells with very large nuclei and thickened cell walls. Similar to the endosperm of other studied palm species, their cells exhibit a quiescent appearance with lipid, protein, minerals (in the cytoplasm) and mannans (in the cell walls) as the insoluble storage reserves. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 145, 445–453.
Fernanda Amanto Gaiotto - One of the best experts on this subject based on the ideXlab platform.
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landscape scale deforestation decreases gene flow distance of a keystone tropical palm Euterpe Edulis mart arecaceae
Ecology and Evolution, 2016Co-Authors: Alesandro Souza Santos, Eliana Cazetta, Pavel Dodonov, Deborah Faria, Fernanda Amanto GaiottoAbstract:Habitat loss represents one of the main threats to tropical forests, which have reached extremely high rates of species extinction. Forest loss negatively impacts biodiversity, affecting ecological (e.g., seed dispersal) and genetic (e.g., genetic diversity and structure) processes. Therefore, understanding how deforestation influences genetic resources is strategic for conservation. Our aim was to empirically evaluate the effects of landscape-scale forest reduction on the spatial genetic structure and gene flow of Euterpe Edulis Mart (Arecaceae), a palm tree considered a keystone resource for many vertebrate species. This study was carried out in nine forest remnants in the Atlantic Forest, northeastern Brazil, located in landscapes within a gradient of forest cover (19-83%). We collected leaves of 246 adults and 271 seedlings and performed genotyping using microsatellite markers. Our results showed that the palm populations had low spatial genetic structure, indicating that forest reduction did not influence this genetic parameter for neither seedlings nor adults. However, forest loss decreased the gene flow distance, which may negatively affect the genetic diversity of future generations by increasing the risk of local extinction of this keystone palm. For efficient strategies of genetic variability conservation and maintenance of gene flow in E. Edulis, we recommend the maintenance of landscapes with intermediary to high levels of forest cover, that is, forest cover above 40%.
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genetic structure mating system and long distance gene flow in heart of palm Euterpe Edulis mart
Journal of Heredity, 2003Co-Authors: Fernanda Amanto Gaiotto, Dario Grattapaglia, Roland VencovskyAbstract:We report a detailed analysis of the population genetic structure, mating system, and gene flow of heart of palm (Euterpe Edulis Mart.‐Arecaceae) in central Brazil. This palm is considered a keystone species because it supplies fruits for birds and rodents all year and is intensively harvested for culinary purposes. Two populations of this palm tree were examined, using 18 microsatellite loci. The species displays a predominantly outcrossed mating system (tm ¼ 0.94), with a probability of full sibship greater than 70% within open-pollinated families. The following estimates of interpopulation genetic variation were calculated and found significant: FIT ¼ 0.17, FIS ¼ 0.12, FST ¼ 0.06, and RST ¼ 0.07. This low but significant level of interpopulation genetic variation indicates high levels of gene flow. Two adult trees were identified as likely seed parents (P . 99.9%) of juveniles located at a distance of 22 km. Gene flow over such distances has not been reported before for tropical tree species. The establishment and management of in situ genetic reserves or ex situ conservation and breeding populations for E. Edulis should contemplate the collection of several hundreds open-pollinated maternal families from relatively few distant populations to maximize the genetic sampling of a larger number of pollen parents.
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microsatellite markers for heart of palm Euterpe Edulis and e oleracea mart arecaceae
Molecular Ecology Notes, 2001Co-Authors: Fernanda Amanto Gaiotto, Dario Grattapaglia, R P V BrondaniAbstract:Euterpe Edulis is the species of palm found in the Atlantic Forest and Cerrado gallery forest that yields the best heart of palm. A battery of 18 highly polymorphic microsatellite markers was developed from an enriched genomic library. Using fluorescence automated detection an average of 10.6 alleles per locus were found on a sample of 66 individuals sampled from a natural population. These loci allow extremely precise paternity testing, estimation of gene flow and of parentage coefficients among trees in the wild.
Guillermo Goldstein - One of the best experts on this subject based on the ideXlab platform.
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growth and leaf production in the tropical palm Euterpe Edulis light conditions versus developmental constraints
Flora, 2011Co-Authors: Maria Genoveva Gatti, Paula I Campanello, Guillermo GoldsteinAbstract:Abstract We studied developmental and environmental constraints on leaf dynamics, morphology and physiology in the monopodial tropical palm of the Atlantic Forest biome, Euterpe Edulis. Plastic responses to light environments in terms of photosynthesis, leaf size, leaf life span, patterns of biomass allocation and growth were analysed. Plants were grown during 14 months in a shade house under four different growth irradiances. Plants of Euterpe Edulis were able to adjust leaf demography and biomass allocation in the different light treatments. Leaf life span increased by 100 days with decreasing light levels while the rate of leaf production decreased, consistent with lower electron transport rates. At low light levels, adjustments in biomass allocation to leaf components allowed E. Edulis to reduce self-shading and increase light interception. At high light plants allocated more biomass to roots, and the plants exhibited small leaf sizes when leaves were compared using an explicit ontogenetic analysis. Ontogeny constrained the maximum size that each consecutive leaf could achieve, while growth irradiance determined the rate of leaf production and other leaf traits. Consequently, there were both, developmental constraints and environmental determinants influencing leaf demography and morphology in E. Edulis. The findings of this ecophysiological and demographic study are relevant to palms growing under natural conditions and help to explain the success of E. Edulis in the forest understory and its absence from large gap openings. Our results not only confirm that E. Edulis is a shade tolerant species, but also show that palms are able to acclimate to different growing condition as well as trees.
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frost resistance in the tropical palm Euterpe Edulis and its pattern of distribution in the atlantic forest of argentina
Forest Ecology and Management, 2008Co-Authors: Genoveva M Gatti, Paula I Campanello, Lia Montti, Guillermo GoldsteinAbstract:Abstract Frost resistance and subzero temperature effects on photosynthesis, survival and distribution were studied in Euterpe Edulis , a tree palm species of the Atlantic Forest, near the southern limit of the species distribution. E. Edulis grows under the forest canopy and is absent from forest stands located near bottom valleys. This palm species has been commercially exploited for palm hearts, making it the most important non-timber forest species in North-Eastern Argentina. Its distribution was studied in relation to the frequency and intensity of subzero temperatures along a topographic gradient. E. Edulis abundance was higher at the highest site and decreased or became absent towards the lowest site. Subzero temperatures during each of three winter seasons were observed in the lowest site. The medium and high elevation sites never experienced absolute minimum temperatures below 0 °C. Forest structure, fraction of solar radiation transmitted through the canopy and soil water potentials did not change substantially along the gradient. After a low temperature period in winter, the maximum quantum yield in E. Edulis leaflets was relatively low in individuals at the low elevation site while having normal values at the medium and high elevation sites. Thermal analysis indicated that E. Edulis saplings can supercool down to about −10 °C and do not tolerate extracellular ice formation. Ice formation was observed at about −4 °C, relatively close to the equilibrium freezing temperature, only after an increase in ambient humidity resulted in dew formation on the plant surface. Dew formation is commonly observed in valleys during the winter season. This observation gives further support to the hypothesis that strong infrequent frost events could be an important environmental factor determining the spatial distribution pattern of E. Edulis in the Atlantic Forest of Argentina.
