Biodegradation of fibrillated oil palm trunk fiber by a novel thermophilic, anaerobic, xylanolytic bacterium Caldicoprobacter sp. CL-2 isolated from compost.

Oil palm trunk (OPT) is one of the most promising lignocellulosic bioresources. To develop effective biodegradation, thermophilic, anaerobic microorganisms were screened from bovine manure compost using fibrillated OPT (f-OPT) pretreated by wet disk milling as the substrate. One thermophilic, anaerobic bacterium, strain CL-2, whose 16S rDNA gene has 98.6% sequence identity with that of Caldicoprobacter faecale DSM 20678T, exhibited high degradation activity (32.7% reduction in total dry solids of f-OPT). Strain CL-2 did not use cellulose as a carbon source, but used hemicelluloses such as xylan, arabinoxylan, starch and pectin at 70 °C. Phylogenetic and morphologic analyses and the polysaccharide use suggest that CL-2 may be classified as a novel species of Caldicoprobacter, named Caldicoprobacter sp. CL-2. To characterize enzymatic activities of CL-2, extracellular enzymes were prepared from culture broth using beechwood xylan as the carbon source. The extracellular enzymes showed high xylanase activity, but low cellulase activity, suggesting that f-OPT degradation may depend on xylanase activity. To understand the xylanase system of CL-2, a major xylanase was cloned and characterized. The xylanase (CalXyn11A) had a modular structure consisting of a glycoside hydrolase (GH) family-11 domain and a family 36 carbohydrate-binding module. CalXyn11A did not show f-OPT degradation activity, but a strong synergistic effect was observed when CalXyn11A was added to the extracellular enzyme preparation. These results indicate that, rather than working alone, CalXyn11A has an important role in enhancing total lignocellulose degradation activity by cooperation with other GHs.

Investigation of Requisites for the Optimal Mycelial Growth of the Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), on Oil Palm Biomass in Malaysia.

Rigorous research has been carried out regarding the cultivation of Ganoderma lucidum using different agricultural residues. Nevertheless, large-scale cultivation and the separation of active compounds of G. lucidum are still challenges for local farmers. The objective of this study was to evaluate the use of oil palm waste fibers such as empty fruit bunch fibers and mesocarp fibers as effective substrates for the growth of G. lucidum mycelia to study the possibility of solid-state cultivation and to determine the optimum conditions necessary for the growth of mycelia of this mushroom on these waste fibers. Various parameters such as temperature, pH, humidity, and carbon and nitrogen compositions required for the optimum growth of mycelia have been determined. Oil palm fibers are a vivid source of lignocellulose, and their availability in Malaysia is high compared to that of sawdust. G. lucidum is a wood-rotting fungi that can easily decay and utilize this lignocellulose biomass, a major agricultural waste in Malaysia.

Involvement of metabolites in early defense mechanism of oil palm (Elaeis guineensis Jacq.) against Ganoderma disease.

Understanding the mechanism of interaction between the oil palm and its key pathogen, Ganoderma spp. is crucial as the disease caused by this fungal pathogen leads to a major loss of revenue in leading palm oil producing countries in Southeast Asia. Here in this study, we assess the morphological and biochemical changes in Ganoderma disease infected oil palm seedling roots in both resistant and susceptible progenies. Rubber woodblocks fully colonized by G. boninense were applied as a source of inoculum to artificially infect the roots of resistant and susceptible oil palm progenies. Gas chromatography-mass spectrometry was used to measure an array of plant metabolites in 100 resistant and susceptible oil palm seedling roots treated with pathogenic Ganoderma boninense fungus. Statistical effects, univariate and multivariate analyses were used to identify key-Ganoderma disease associated metabolic agitations in both resistant and susceptible oil palm root tissues. Ganoderma disease related defense shifts were characterized based on (i) increased antifungal activity in crude extracts, (ii) increased lipid levels, beta- and gamma-sitosterol particularly in the resistant progeny, (iii) detection of heterocyclic aromatic organic compounds, benzo [h] quinoline, pyridine, pyrimidine (iv) elevation in antioxidants, alpha- and beta-tocopherol (iv) degraded cortical cell wall layers, possibly resulting from fungal hydrolytic enzyme activity needed for initial penetration. The present study suggested that plant metabolites mainly lipids and heterocyclic aromatic organic metabolites could be potentially involved in early oil palm defense mechanism against G. boninense infection, which may also highlight biomarkers for disease detection, treatment, development of resistant variety and monitoring.

Lignin preparation from oil palm empty fruit bunches by sequential acid/alkaline treatment--A biorefinery approach.

Lignin is an important raw material for the sustainable biorefineries and also the forerunner of high-value added products, such as biocomposite for chemical, pharmaceutical and cement industries. Oil palm empty fruit bunches (OPEFB) were used for lignin preparation by successive treatment with 1% (w/w) H2SO4 at 121°C for 60 min and 2.5% NaOH at 121°C for 80 min resulting in the high lignin yield of 28.89%, corresponding to 68.82% of the original lignin. The lignin obtained was characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The results indicated a lignin with molecular masses ramping from 4500 kDa to 12,580 kDa. FTIR and NMR of these lignins showed more syringyl and p-hydroxyphenyl than guaiacyl units. Moderate acid/alkaline treatment provided lignin with high industrial potential and acid hydrolyzates rich in fermentable sugars and highly porous cellulosic fibers.

Hydrothermal and wet disk milling pretreatment for high conversion of biosugars from oil palm mesocarp fiber.

Eco-friendly pretreatment methods for lignocellulosic biomass are being developed as alternatives to chemical based methods. Superheated steam (SHS), hot compressed water (HCW) and wet disk milling (WDM) were used individually and with combination to partially remove hemicellulose and alter the lignin composition of recalcitrant structure of oil palm mesocarp fiber (OPMF). The efficiency of the pretreatment methods was evaluated based on the chemical compositions altered, SEM analysis, power consumption and degree of enzymatic digestibility. Hemicellulose removal (94.8%) was more pronounced under HCW compared to SHS, due to maximal contact of water and production of acetic acid which enhanced further degradation of hemicellulose. Subsequent treatment with WDM resulted in defibrillation of OPMF and expansion of the specific surface area thus increasing the conversion of cellulose to glucose. The highest glucose yield was 98.1% (g/g-substrate) when pretreated with HCW (200 °C, 20 min) and WDM which only consumed 9.6 MJ/kg of OPMF.

Lipid-dissolved γ-carotene, ß-carotene, and lycopene in globular chromoplasts of peach palm (Bactris gasipaes Kunth) fruits.

MAIN CONCLUSION: High levels of ß-carotene, lycopene, and the rare γ-carotene occur predominantly lipid-dissolved in the chromoplasts of peach palm fruits. First proof of their absorption from these fruits is reported. The structural diversity, the physical deposition state in planta, and the human bioavailability of carotenoids from the edible fruits of diverse orange and yellow-colored peach palm (Bactris gasipaes Kunth) varieties were investigated. HPLC-PDA-MS(n) revealed a broad range of carotenes, reaching total carotenoid levels from 0.7 to 13.9 mg/100 g FW. Besides the predominant (all-E)-ß-carotene (0.4-5.4 mg/100 g FW), two (Z)-isomers of γ-carotene (0.1-3.9 mg/100 g FW), and one (Z)-lycopene isomer (0.04-0.83 mg/100 g FW) prevailed. Approximately 89-94 % of total carotenoid content pertained to provitamin A carotenoids with retinol activity equivalents ranging from 37 to 609 µg/100 g FW. The physical deposition state of these carotenoids in planta was investigated using light, transmission electron, and scanning electron microscopy. The plastids found in both orange and yellow-colored fruit mesocarps were amylo-chromoplasts of the globular type, containing carotenoids predominantly in a lipid-dissolved form. The hypothesis of lipid-dissolved carotenoids was supported by simple solubility estimations based on carotenoid and lipid contents of the fruit mesocarp. In our study, we report first results on the human bioavailability of γ-carotene, ß-carotene, and lycopene from peach palm fruit, particularly proving the post-prandial absorption of the rarely occurring γ-carotene. Since the physical state of carotenoid deposition has been shown to be decisive for carotenoid bioavailability, lipid-dissolved carotenoids in peach palm fruits are expected to be highly bioavailable, however, further studies are required.

The structure-mechanical relationship of palm vascular tissue.

The structure-mechanical relationship of palm sheath is studied with numerical and experimental methods. The cellular structure of the vascular tissue is rebuilt with an image-based reconstruction method and used to create finite element models. The validity of the models is firstly verified with the results from the tensile tests. Then, the cell walls inside each of the specific regions (fiber cap, vessel, xylem, etc.) are randomly removed to obtain virtually imperfect structures. By comparing the magnitudes of performance degradation in the different imperfect structures, the influences of each region on the overall mechanical performances of the vascular tissue are discussed. The longitudinal stiffness and yield strength are sensitive to the defects in the vessel regions. While in the transverse directions (including the radial and tangential directions), the parenchymatous tissue determines the mechanical properties of the vascular tissue. Moreover, the hydraulic, dynamic response and energy absorption behavior of the vascular tissue are numerically explored. The flexibility of natural palm tissue enhances its impact resistance. Under the quasi-static compression, the cell walls connecting the fiber cap and the vessel dissipate more energy. The dominant role of the fiber cap in the plastic energy dissipation under high-speed impact is observed. And the radially-arranged fiber cap also allows the palm tissue to improve its tangential mechanical performances under hydraulic pressure.

Phenotyping date palm varieties via leaflet cross-sectional imaging and artificial neural network application.

BACKGROUND: True date palms (Phoenix dactylifera L.) are impressive trees and have served as an indispensable source of food for mankind in tropical and subtropical countries for centuries. The aim of this study is to differentiate date palm tree varieties by analysing leaflet cross sections with technical/optical methods and artificial neural networks (ANN). RESULTS: Fluorescence microscopy images of leaflet cross sections have been taken from a set of five date palm tree cultivars (Hewlat al Jouf, Khlas, Nabot Soltan, Shishi, Um Raheem). After features extraction from images, the obtained data have been fed in a multilayer perceptron ANN with backpropagation learning algorithm. CONCLUSIONS: Overall, an accurate result in prediction and differentiation of date palm tree cultivars was achieved with average prediction in tenfold cross-validation is 89.1% and reached 100% in one of the best ANN.

Morphoanatomy of the flower of Syagrus inajai (SPRUCE) Becc. (Arecaceae- Arecoideae- Attaleinae), Amazon.

The occurrence of Syagrus inajai (Spruce) Becc., popularly known as pupunha palm, among other names, has been registered in the Guianas and in the North of Brazil in areas of terra firme (non-flooding) and gallery forests. In order to characterize the inflorescence and further knowledge of this family, a morphoanatomical study was carried out of the palm S. inajai in a green area of the Campus of the Federal University of Amazonas--UFAM, Manaus, Amazonas. The inflorescences are branched to one order, pedunculate, and interfoliar, measuring 62-82 cm in length, with woody bracts with longitudinal grooves on the external surface, and flowers in triads. The number of flowers to each inflorescence varies from 5,904 to 17,316 for staminate flowers, and from 180 to 3,528 for pistillate flowers. Staminate flowers with six anthers and one vascular bundle each; three-lobed pistillodium, vascularized pistillodium. Its pistillate flowers have six staminodia joined to form a circle, syncarpic, tricarpellary, trilocular gynoecium, one ovule to each locule, synascidiate in the ovary, and plicated above. Tripartite stigma, apical and sessile, with epidermis composed of elongated papillary cells, pattern of epidermis that is maintained throughout the stylar canal. Bitegmented, anatrope, pachychalazal ovule.

Induction and characterization of oil palm (Elaeis guineensis Jacq.) pro-embryogenic masses.

Oil palm is one of the most economically valuable oil seed plants, but the expansion of plantations has been limited by availability of seedlings, as the conventional propagation is through seeds, which have low germination rates. One possible solution for the large-scale production is the use of somatic embryogenesis. The aim of this study was evaluate the effects auxins 2,4-D and picloram on the induction of pro-embryogenic masses in E.guineenesis hybrid leaf explants and characterize, regarding embryogenic characteristics, with cytochemical and ultrastructural analysis. Specifically, in vitro plantlets leaves fragments were inoculated in Y3 culture medium supplemented by 2.4-D or picloram at different concentrations (0.0, 1.0, 3.0, 6.0 and 9.0 mg l⁻¹). After 90 days the presence/ absence of cell masses were evaluated. Both growth regulators efficiently induced cellular masses regardless of the concentrations applied. As the cell masses were not homogeneously formed, they were classified according to color and shape into four types: TYPE 1--elongated and translucent, TYPE 2--uneven and translucent, TYPE 3--globular and beige, TYPE 4--globular and white. Based on the anatomical and ultrastructural features, TYPE 2, 3 and 4 cell masses were considered to have the highest embryogenic potential and therefore may be most suited to large-scale vegetative propagation of oil palm.

Morphoanatomy of the flower of Syagrus inajai (SPRUCE) Becc. (Arecaceae- Arecoideae- Attaleinae), Amazon / Morfoanatomia floral de Syagrus inajai (Spruce) Becc. (Arecaceae- Arecoideae- Attaleinae), Amazônia

The occurrence of Syagrus inajai (Spruce) Becc., popularly known as pupunha palm, among other names, has been registered in the Guianas and in the North of Brazil in areas of terra firme (non-flooding) and gallery forests. In order to characterize the inflorescence and further knowledge of this family, a morphoanatomical study was carried out of the palm S. inajai in a green area of the Campus of the Federal University of Amazonas - UFAM, Manaus, Amazonas. The inflorescences are branched to one order, pedunculate, and interfoliar, measuring 62-82 cm in length, with woody bracts with longitudinal grooves on the external surface, and flowers in triads. The number of flowers to each inflorescence varies from 5,904 to 17,316 for staminate flowers, and from 180 to 3,528 for pistillate flowers. Staminate flowers with six anthers and one vascular bundle each; three-lobed pistillodium, vascularized pistillodium. Its pistillate flowers have six staminodia joined to form a circle, syncarpic, tricarpellary, trilocular gynoecium, one ovule to each locule, synascidiate in the ovary, and plicated above. Tripartite stigma, apical and sessile, with epidermis composed of elongated papillary cells, pattern of epidermis that is maintained throughout the stylar canal. Bitegmented, anatrope, pachychalazal ovule.

Syagrus inajai (Spruce) Becc., popularmente conhecida como pupunha-brava entre outras denominações, teve sua ocorrência registrada para Guianas e no norte do Brasil em áreas de floresta de terra firme e floresta de galeria. Com o intuito de caracterizar a inflorescência ampliando o conhecimento a respeito da família foi realizado o estudo morfoanatômico da palmeira S. inajai, em área verde do Campus da Universidade Federal do Amazonas - UFAM, Manaus, Amazonas. A inflorescência é ramificada em primeira ordem, pedunculada, interfoliar com 62-82 cm de comprimento, bráctea lenhosa com fissuras longitudinais na superfície externa e flores em tríades. O número de flores por inflorescência varia entre 5.904 - 17.316 para flores estaminadas e 180 - 3.528 para as flores pistiladas. Flores estaminadas com seis anteras e um feixe vascular cada; pistilódio trífido e vascularizado. Flores pistiladas com seis estaminódios unidos formando um círculo. Gineceu sincárpico, tricarpelar, trilocular, um óvulo por lóculo, sinascidiado no ovário e plicado acima. Estigma tripartido, apical e séssil, com epiderme composta por células papilosas alongadas, padrão de epiderme que se mantem por todo canal estilar. Óvulo é anátropo, paquicalazal e bitegumentado.

Arabinogalactan proteins and the extracellular matrix surface network during peach palm somatic embryogenesis.

Somatic embryogenesis has been described in peach palm as a reliable method for its in vitro multiplication and conservation. In this study, we evaluated the possible role of arabinogalactan proteins (AGPs) during this morphogenetic pathway. The presence of Yariv reagent, a synthesized chemical antibody that specifically binds AGP molecules, affected somatic embryos and callus development rate, but no effect was observed on fresh weight increment. This substance also had profound effects on embryo morphology: somatic embryos presented loose cells in the protoderm and no signs of polarization could be observed. To better evaluate the role of AGPs, analyses of specific monoclonal antibodies (MAbs) against different AGP epitopes revealed a specific pattern of distribution for each epitope. MAb JIM13 had differential expression and showed intense signal on the embryogenic sector and some immediately adjacent layers. MAb JIM7 against pectin recognized cell walls and a specific layer over the developing somatic embryo, as well as over the shoot meristem region of mature somatic embryos. This corresponds to an extracellular matrix surface network (ECMSN) associated with the development of somatic embryos and closely related to the expression of MAb JIM13. Scanning electron microscopy confirmed the presence of an ECMSN covering a specific group of cells and ultra-structural analyses revealed that the ECMSN had lipophilic substances.

External mouthpart morphology in the Tenuipalpidae (Tetranychoidea): Raoiella a case study.

The use of low-temperature scanning electron microscopy (LTSEM) to study external mouthpart morphology in the Tenuipalpidae, in particular the genus Raoiella, has brought some aspects of the mechanics of feeding in this group into question. In addition, an LTSEM study on the specialized feeding behaviour of Raoiella indica Hirst (Tetranychoidea: Tenuipalpidae) revealed host plant use in this species could be affected by stomatal complex morphology.

Cytological and physiological changes in recalcitrant Chinese fan palm (Livistona chinensis) embryos during cryopreservation.

Cytological and physiological changes during cryopreservation were investigated in Livistona chinensis embryos excised 42 weeks after flowering. Both dehydration and freezing caused numerous cellular ultrastructural alterations. Dehydration seriously impaired plasma membrane integrity, while freezing caused a further increase in electrolyte leakage. Damage to cellular ultrastructure and plasmalemma integrity had an inverse relationship with water content in unfrozen embryos and a positive relationship in frozen embryos. Changes in activity of antioxidant enzymes differed during cryopreservation. Dehydration and freezing had little effect on superoxide dismutase activity, although these treatments greatly reduced embryo viability. Activity of dehydroascorbate reductase (DHAR) and glutathione reductase (GR) changed only slightly during dehydration, but dehydration markedly decreased activity of ascorbate peroxidase (APX) and catalase (CAT). Freezing further decreased APX and GR activity but increased CAT activity in dehydrated samples. A novel DHAR isozyme was induced during the freeze-thaw cycle. Membrane lipid peroxidation was detected in the control embryos, and was promoted by both dehydration and freezing. The malondialdehyde (MDA) content in post-thaw embryos increased by a maximum of 30%. Thus, changes in viability of embryos were closely related to damage to cellular ultrastructure and plasmalemma integrity, but were not directly related to antioxidant activity nor MDA accumulation.

Compound leaf development in the palm Chamaedorea elegans is KNOX-independent.

PREMISE OF THE STUDY: How a leaf acquires its shape is a major and largely unresolved question in plant biology. This problem is particularly complex in the case of compound leaves, where the leaf blade is subdivided into leaflets. In many eudicots with compound leaves, class I KNOTTED1-LIKE HOMEOBOX (KNOX) genes are upregulated in the leaf primordium and promote leaflet initiation, while KNOX genes are restricted to the shoot apical meristem in simple-leaved plants. In monocots, however, little is known about the extent of KNOX contribution to compound leaf development, and we aimed to address this issue in the palm Chamaedorea elegans. METHODS: We investigated the accumulation pattern of KNOX proteins in shoot apical meristems and leaf primordia of the palm C. elegans using immunolocalization experiments. KEY RESULTS: KNOX proteins accumulated in vegetative and inflorescence apical meristems and in the subtending stem tissue, but not in the plicated regions of the leaf primordia. These plicated areas form during primary morphogenesis and are the only meristematic tissue in the developing primordium. In addition, KNOX proteins did not accumulate in any region of the developing leaf during secondary morphogenesis, when leaflets separate to create the final pinnately compound leaf. CONCLUSIONS: The compound leaf character in palms, C. elegans in particular and likely other pinnately compound palms, does not depend on the activities of KNOX proteins.

Multiple bud cultures of 'Barhee' date palm (Phoenix dactylifera) and physiological status of regenerated plants.

Adventitious bud clusters of date palm 'Barhee' were successfully established from juvenile leaves (<1cm) using reduced amounts of 2,4-D (0.2mgL(-1)) to limit the risk of somaclonal variation. An average of 8.4 adventitious buds per explant were obtained. Histological examination showed that the superficial cell layers of leaves had the highest caulogenic capacity. High sucrose concentration (70gL(-1)) was used for the conversion of initial buds to multiple bud clusters. The promoting effect of temporary immersion on shoot proliferation was found to be significant when compared to cultivation on solid media. Elongation of shoots was also better using a thin film of PGR-free liquid medium instead of a solid medium. Anatomical observations indicated that roots from vitroplants were potentially functional at various developmental stages. However, only 12-month-old vitroplants were found to be physiologically able to control transpirational vapor loss. Additionally, the photochemical activity of photosystem II in these vitroplants was close to that measured in plants that were already acclimatized. As a result, 83.3% of regenerated plants were successfully acclimatized. No phenotypic variation was observed among more than 500 adventitious bud-derived plants. All regenerants survived after field transplantation. We found that the production of adventitious bud clusters in small bioreactors was able to provide an efficient micropropagation system for date palm cv. 'Barhee'. An in vitro hardening step was a prerequisite for the successful transfer of vitroplants in soil.

Ontogeny and structure of the acervulate partial inflorescence in Hyophorbe lagenicaulis (Arecaceae; Arecoideae).

BACKGROUND AND AIMS: The palm tribe Chamaedoreeae displays flowers arranged in a complex partial inflorescence called an acervulus. This type of partial inflorescence has so far not been reported elsewhere in the largest palm subfamily Arecoideae, which is traditionally characterized by flowers predominantly arranged in triads of one central female and two lateral male flowers. The ontogenetic basis of the acervulus is as yet unknown and its structural diversity throughout the genera of the Chamaedoreeae poorly recorded. This study aims to provide critical information on these aspects. METHODS: Developmental series and mature inflorescences were sampled from plants cultivated in international botanical gardens and wild populations. The main techniques employed included scanning electronic microscopy and serial anatomical sectioning of resin-embedded fragments of rachillae. KEY RESULTS: Inflorescence ontogeny in Hyophorbe lagenicaulis demonstrates that the acervulus and the inflorescence rachilla form a condensed and cymose branching system resembling a coenosome. Syndesmy results from a combined process of rapid development and adnation, without or with reduced axis elongation. Acervulus diversity in the ten taxa of the Chamaedoreeae studied is displayed at the level of their positioning within the inflorescence, their arrangement, the number of floral buds and their sexual expression. CONCLUSIONS: The results show that a more general definition of the type of partial inflorescence observed within the large subfamily Arecoideae would correspond to a cyme rather than to a floral triad. In spite of their common cymose architecture, the floral triad and the acervulus present differences with respect to the number and arrangement of floral buds, the superficial pattern of development and sexual expression.

Use of palmae wax hydrocarbon fractions as chemotaxonomical markers in Butia and Syagrus.

The wax hydrocarbon fractions of native Butia and Syagrus species collected from Palms in different regions of the of Rio Grande do Sul state (Brazil) and in Rocha (Uruguay) were analyzed to evaluate their potential as chemotaxonomic markers. The wax was extracted with chloroform and the resulting wax was fractionated by preparative TLC. The hydrocarbon fractions were analyzed by GC-MS. Statistical analyses were completed with the Statistica 5.0 program. The total crude wax yields averaged 0.31% w.w-1 dried leaves for Butia samples and 0.28% for Syagrus samples. The linear hydrocarbons represented on average 15% of the total waxes in the case of Butia samples and 13.7% in Syagrus samples. Hentriacontane and triacontane were the main components of all samples. The comparison of the means showed significant differences among Butia and Syagrus samples, and amongst Butia samples collected in different localities. In the case of the Syagrus collections no consistent groupings could be made. In the case of Butia samples the formation of three groupings could be observed, which were consistent with the species described for their geographical distribution. These results are discussed in the paper.

Use of palmae wax hydrocarbon fractions as chemotaxonomical markers in Butia and Syagrus / Uso de frações de hidrocarbonetos de palmeiras como marcadores quimiotaxonômicos em Butia e Syagrus

The wax hydrocarbon fractions of native Butia and Syagrus species collected from Palms in different regions of the of Rio Grande do Sul state (Brazil) and in Rocha (Uruguay) were analyzed to evaluate their potential as chemotaxonomic markers. The wax was extracted with chloroform and the resulting wax was fractionated by preparative TLC. The hydrocarbon fractions were analyzed by GC-MS. Statistical analyses were completed with the Statistica 5.0 program. The total crude wax yields averaged 0.31% w.w–1 dried leaves for Butia samples and 0.28% for Syagrus samples. The linear hydrocarbons represented on average 15% of the total waxes in the case of Butia samples and 13.7% in Syagrus samples. Hentriacontane and triacontane were the main components of all samples. The comparison of the means showed significant differences among Butia and Syagrus samples, and amongst Butia samples collected in different localities. In the case of the Syagrus collections no consistent groupings could be made. In the case of Butia samples the formation of three groupings could be observed, which were consistent with the species described for their geographical distribution. These results are discussed in the paper.

Frações de hidrocarbonetos das ceras de espécies nativas de Butia e Syagrus coletadas de palmeiras em diferentes regiões do Rio Grande do Sul (Brasil) e em Rocha (Uruguai) foram analisadas para avaliar o seu potencial como marcadores quiomiotaxonômicos. As ceras foram extraídas com clorofórmio e fracionadas por TLC preparativo. As frações de hidrocarbonetos foram analisadas por CG-EM. As análises estatísticas foram realizadas com auxílio do programa Statistica 5.0. O rendimento total de cera das folhas secas foi de 0,31% g.g–1 para as amostras de Butia e de 0,28% para Syagrus. Os hidrocarbonetos lineares representaram em média 15 e 13% do total das ceras para Butia e Syagrus, respectivamente. Hentriacontano e triacontano foram os compostos majoritários em todas as amostras. A comparação de médias mostrou diferenças significativas entre as amostras de Butia e Syagrus e entre as amostras de Butia coletadas em diferentes localidades. As amostras de Syagrus não formaram agrupamentos relacionados com os locais de coleta. Já no caso de Butia, três agrupamentos puderam ser observados e são consistentes com a distribuição geográfica desta espécie. Estes resultados são discutidos no trabalho.

Detection of dehydrin-like proteins in embryos and endosperm of mature Euterpe edulis seeds.

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.