Browsing by Author "Teixeira, Generosa"
Now showing 1 - 10 of 22
Results Per Page
Sort Options
- Anatomia das plantas. Estruturas secretorasPublication . Moreira, Ilídio; Teixeira, Generosa; Monteiro, Ana
- Assessment of the essential oil composition of Tornabenea annua, Tornabenea insularis and Tornabenea tenuissima fruits from Cape Verde IslandsPublication . Grosso, Clara; Teixeira, Generosa; Gomes, Isildo; Martins, Eurico S.; Barroso, Jose G.; Pedro, Luis G.; Figueiredo, A. CristinaThe essential oils of Tornabenea annua, Tornabenea insularis and Tornabenea tenuissima herbarium or in vivo fruits, collected in Fogo, Santiago, Santo Antao, Sao Nicolau and Sao Vicente Islands, from Cape Verde archipelago, or from plants grown in Lisbon, Portugal, were isolated by hydrodistillation and analysed by CC and CC-MS. The yellowish oils were obtained in variable average yields, lower in herbarium samples [0.05% (v/w)] and higher from in vivo samples [1.3% (v/w)]. Whereas T annua fruits' oils were all dominated by myristicin (92-100%), most of the T insularis fruit samples' oils were elemicin rich (82-90%). No clear information could be obtained for T tenuissima fruits' oils as each of the samples gave different chemical composition. Cluster analysis of the essential oil composition from the fruits' samples studied, confirmed these chemical differences. (C) 2009 Elsevier Ltd. All rights reserved.. - European Social Fund [211 015]. - We are grateful to the curator of IICT Herbarium (LISC), for the access facilities to the herbarium specimens, to the technicians from Parque Nacional de Serra Malagueta, Santiago Island, and from Tapada da Ajuda, ISA, UTL. This study was partially funded by a grant from European Social Fund 211 015 (PRODEP III - 3.2).
- Chemical composition and antibacterial activity of essential oils from the medicinal plant Mentha cervina L. grown in PortugalPublication . Rodrigues, Leandra; Duarte, Aida; Figueiredo, Ana Cristina; Brito, Luísa; Teixeira, Generosa; Moldão, Margarida; Monteiro, AnaMentha cervina is a medicinal plant traditionally used in Portugal in folk medicine, in different gastric disorders and inflammations of the respiratory tract. In order to validate those traditional uses, M. cervina essential oils (EOs) were characterized by GC and GC–MS and their antimicrobial activity was tested against 23 bacterial strains (including multiresistant strains). The EOs were dominated by the monoterpenes pulegone (52–75%), isomenthone (8–24%), limonene (4–6%), and menthone (1–2%). The antibacterial activity of these EOs was compared to that of the main components standards. The most effective antibacterial activity was expressed by the EOs against the Gram-negative bacteria, Escherichia coli and Acinetobacter baumanni, with MIC values of 1 mg/ml. The EOs complex mixtures were more active than the individual aromatic components supporting the hypothesis that the EOs antibacterial activity is a function of the synergistic effect of their different aromatic components. These results show the potential role of M. cervina EOs as antibacterial agents and validate the traditional use of this plant.
- Comparative leaf micromorphoanatomy of Vitis vinifera SSP.vinifera (Vitaceae) red cultivarsPublication . Monteiro, Ana; Teixeira, Generosa; Lopes, C.M.Aiming to characterize and discriminate between four red grapevine cultivars – ‘Aragonez’ (AR), ‘Cabernet Sauvignon’ (CS), ‘Syrah’ (SY) and ‘Touriga Nacional’ (TN) – grown under Mediterranean field conditions, we studied their leaf micromorphoanatomic characteristics under light (LM) and scanning electron microscopy (SEM). The studied characteristics included those of the epidermis, stomata and hair distribution, and the mesophyll structure. The individual primary leaf area revealed significant differences between cultivars, with the highest value presented by AR and the lowest by CS, while SY and TN gave intermediate values. CS presented a significantly higher leaf specific dry weight value than the other three cultivars, which returned similar values. Under SEM magnification three types of stomata were identified in all the studied genotypes: sunken, at the same level, and raised above the other epidermal cells. Each cultivar displayed different percentages of these types of stomata: the highest raised-above values were observed in AR; TN had the highest same-level values and the lowest sunken ones; CS revealed the highest values for sunken stomata; while SY returned average values for all the types of stomata. Stomatal density was higher in AR and SY and lower in CS and TN. The hairs on the lower surface presented a similar woolly aspect in all the studied cultivars, but the mesophyll structure was quite different: CS presented the highest and AR the lowest values for total thickness of the lamina, thickness of palisade and spongy parenchyma, and length and thickness of upper and lower epidermal cells; the values for these leaf features in TN and SY fell between those for CS and AR. The data suggest that differences in leaf micromorphoanatomy can be used to distinguish between grapevine cultivars. Further studies are needed to confirm whether there is any association between some of these leaf traits – e.g. stomata type and mesophyll structure – and the physiological behaviour observed under field conditions.
- Essential oil composition of Pterospartum tridentatum grown in PortugalPublication . Grosso, A. Clara; Costa, Monya M.; Ganco, Luisa; Pereira, Ana L.; Teixeira, Generosa; Lavado, Jose M. G.; Figueiredo, A. Cristina; Barroso, Jose G.; Pedro, Luis G.The essential oils, isolated by hydrodistillation and distillation-extraction, from the aerial parts of different populations of Pterospartum tridentatum collected during the flowering phase, at different locations in Portugal, were analysed by GC and GC-MS. All the P. tridentatum populations studied afforded a yellowish oil in a yield 0.05% (v/w). cis-Theaspirane (2-14%), trans-theaspirane (2-17%) and octen-3-ol (2-37%) were, in variable amounts, the dominant components of the oils. Cluster analysis of the essential oil compositions from the nine populations studied, confirmed a major chemical variability. (c) 2006 Elsevier Ltd. All rights reserved.
- Harnessing sediments of coastal aquaculture ponds through technosols construction for halophyte cultivation using saline water irrigationPublication . Cortinhas, Ana; Caperta, Ana D.; Teixeira, Generosa; Carvalho, Luísa; Abreu, Maria ManuelaThe Mediterranean aquaculture has been developed mostly in brackish environment in inactive coastal salt production areas. This study aims to utilise Technosols made with aquaculture sediments for Limonium algarvense Erben cultivation. This species that has nutraceutical potential thrives in halophilic environments in the southwest of the Iberian Peninsula and in Morocco. A microcosm assay was set up with plants grown in bottom sediments (C+), commercial substrate (C-), and Technosols with amendments mixture application at 180 g/kg (Tec180) or at 360 g/kg (Tec360). These plants were irrigated with saline (assay 1) and/or with deionised water (assay 2). The bottom pond sediments, coffee wastes and the estuarine water were evaluated for diverse physicochemical parameters. Plant growth was characterised through a combined methodology using morphometric, SEM and physiological analysis. The Technosols were constructed with bottom sediments and a mixture of organic wastes used as amendments. Results revealed that the bottom sediments had low pH 3.2, Corg and extractable P and K contents, and high electroconductivity (EC) and N-NH4 concentration. The estuarine water had a neutral pH, high EC and high Cl-, HCO3-, Na+, Mg2+ and Ca2+ but low N-NO3- content. The Technosols showed a significant increase of pH, Corg, K and P and a decrease in N-NH4 and EC in comparison with sediments. Principal component analysis separated the different experiments in three groups: C-, A1 and A2 assays. The C- was highly correlated with Corg, P, K, N-NO3 parameters and total ascorbate. The A1 assay showed a strong association with Na, Ca and EC parameters, whereas the A2 assay presented a strongly correlation with plant growth. Plants from Technosols had greater development when irrigated with deionised water than under salty irrigation as opposed to plants cultivated in unamend sediments. In conclusion, these results support that highly saline sediments could be valorised through Technosols construction to cultivate plants with saline water, with potential application in the agro-food and pharmaceutical industry.
- In vitro assessment of the synergism between extracts of Zanthoxylum zanthoxyloides and Zanthoxylum leprieurii and some standard antibioticsPublication . Gonçalves, Marta; Madureira, Ana M.; Catarino, Luís; Monteiro, Ana; Teixeira, GenerosaPurpose: To survive in harsh environments, plants developed functional and metabolic adaptive mechanisms. One of the most relevant defense strategies is the biosynthesis of secondary metabolites, including terpenoids, alkaloids, flavonoids, and phenolics that are accumulated in cellular organelles or secretory structures. Hence, plants are recognized as a valuable source of natural products and for thousands of years very diverse herbal formulations were created to treat several diseases. Zanthoxylum zanthoxyloides and Zanthoxylum leprieurii, two Rutaceae species native to Guinea-Bissau, are well known for their ethnopharmacological relevance. Methods: In the present study, the in vitro antimicrobial activity of these plants against human pathogens was assessed and the phytochemical profile was screened. The extracts of roots and young leaves were obtained by sequential extraction of increasing polarity (n-hexane, CH2Cl2, EtOAc, MeOH and H2O) and tested against Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined, as well as the evaluation of the synergic potential of the extracts. Results: Z. leprieurii leaves extracts, the most apolar ones, had the highest antimicrobial activity, being able to inhibit the growth of Enterococcus hirae and all the Staphylococcus strains assayed, including the resistant ones. A synergic effect between the Zanthoxylum species extracts and standard antibiotics was found, reverting the activity of resistant strains. The phytochemical screening revealed the presence of terpenes, flavonoids, and phenolic compounds, known to have antibacterial properties. Conclusions: The obtained results point to the validation of their use in tradition medicine and emphasize the worthwhile of additional studies of these species to better understand the compounds and mechanisms that may be valuable to restore antibacterial activity
- Leaf morphoanatomy of four red grapevine cultivars grown under the same terroirPublication . Monteiro, Ana; Teixeira, Generosa; Santos, Cristina; Lopes, C.M.This study compare leaf morphoanatomical characteristics of four red cultivars - ‘Touriga Nacional’, ‘Trindadeira’, ‘Cabernet Sauvignon’ and ‘Syrah’ -, grown side by side at the same terroir. The analyzed leaf traits, under light and scanning electron microscopy, showed large variability among genotypes. ‘Trincadeira’ has the biggest single leaf area and ‘Cabernet Sauvignon’ the smallest one. ‘Touriga Nacional’ showed the lowest leaf dry weight and ‘Trincadeira’ the highest one, nonetheless there was no significantly differences in leaf dry mass per area and in leaf density. Leaf dry mass per area was positively correlated with leaf density but showed no correlation with leaf thickness. The French genotypes presented higher thickness of the leaf anatomical traits than the two Portuguese ones. ‘Trincadeira’ showed significantly highest stomata density while the other cultivars showed no significant differences among them. The analyses of the three types of stomata revealed that ‘Trincadeira’ has the lower percentage of raised above and the highest percentage of sunken stomata while ‘Cabernet Sauvignon’ showed the opposite behaviour. The hairs on the lower surface presented a similar woolly aspect in all cultivars. The possible role of leaf morphoanatomical characteristics in determining the cultivars adaptation to abiotic stresses is suggested and discussed
- Leaf morphoanatomy of portuguese autoctones white grapevine cultivars of different geographical originPublication . Santos, Cristina; Teixeira, Generosa; Monteiro, AnaThe knowledge of grapevine varieties leaf morphoanatomy is an important tool to understand the taxa ability to adapt and produce under biotic and abiotic stresses. Aiming to characterize and discriminate between four white Portuguese grapevine (Vitis vinifera subsp. vinifera) varieties – ‘Alvarinho’ (Al), ‘Arinto’ (Ar), ‘Encruzado’ (En) and ‘Viosinho’ (Vi) - from different Winegrowing Regions (Vinhos Verdes, Lisboa, Dão and Douro, respectively), grown side by side in field conditions -, leaf morphoanatomic characteristics were studied under light (LM) and scanning electron microscopy (SEM). The individual primary leaf area revealed significant differences between all cultivars, with the highest value presented by ‘Arinto’ and the lowest by ‘Viosinho’, while ‘Encruzado’ and “Alvarinho” gave intermediate values. Nevertheless, no significant differences were detected on leaf specific dry weight which can be explained by the quite different mesophyll structure. ‘Arinto’ presented the lowest values for total thickness of the lamina, thickness of palisade and spongy parenchyma. The length and thickness of upper and lower epidermal cells of the four cultivars were similar. Under SEM magnification three types of stomata were identified in all the studied genotypes: sunken, at the same level, and raised above the other epidermal cells. No significant differences were registered between cultivars for same-level and sunken stomata values and for stomatal density. ‘Alvarinho’ showed the highest percentage of total for raised-above stomata and ‘Viosinho’ the lowest values. In conclusion, the data indicate some differences in leaf morphoanatomy between grapevine cultivars. Are these grapevine leaf traits differences – e.g. stomata type and mesophyll structure – involved in the differential behavior observed under field conditions? Further studies are needed
- Leaf morphoanatomy traits in white grapevine cultivars with distinct geographical originPublication . Teixeira, Generosa; Monteiro, Ana; Santos, Cristina; Lopes, C.M.This study aims to compare the leaf morphoanatomical characteristics of seven Vitis vinifera subsp. vinifera white cultivars with different geographical origin, grown side by side at the same “terroir”. The leaf morphoanatomical traits analyzed under light and scanning electron microscopy (SEM) showed large variability among genotypes. Significant differences between cultivars were observed in single leaf area, specific leaf area, leaf density and in the thickness of cuticle, upper and lower epidermal cells and mesophyll. Leaf dry mass per area presented a significant positive correlation with leaf density but showed no correlation with leaf thickness, results that can be explained by the quite different mesophyll structure, epidermal cells and cuticle thickness. ‘Alvarinho’, ‘Encruzado’, ‘Macabeu’ and ‘Viosinho’ were the cultivars with the highest thickness of cuticle and mesophyll tissues. Under SEM magnification three types of stomata were identified: sunken, at the same level and raised above, with the same level type presenting the higher percentage in all cultivars. Stomata density presented significant differences between cultivars, with ‘Macabeu’ showing the highest value and ‘Alvarinho’ and ‘Arinto’ the lowest ones. The hairs on the lower surface presented a similar woolly aspect in all cultivars. Calcium oxalate crystals, raphids and druses were visible and widely distributed in the parenchyma tissues. The observed differences in leaf traits among genotypes suggest a major role of leaf anatomy in determining grapevine capacity for coping with different environmental conditions
- «
- 1 (current)
- 2
- 3
- »