Browsing by Author "Moreira, Helena"
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- Application of maize and efficient rhizospheric microorganisms for the remediation of saline soilsPublication . Moreira, Helena; Pereira, Sofia A.; Vega, Alberto L.; Castro, Paula M. L.; Marques, Ana P. G. C.Soil salinity is a serious problem causing loss of fertility, as plants facing salt stress suffer alterations in physiology that adversely affects its growth. This work aimed to evaluate the effectiveness of combinations of microorganisms for the recovery of crop productivity in soils affected by different levels of salinity (0, 2.5 and 5 gNaCl.kg-1). The strategy relied on the culture in greenhouse conditions of a high value food and energetic crop (maize) inoculated with soil plant growth promoting microbiota – an arbuscular mychorrizal fungi (Rhizophagus irregularis), a rhizobacteria (Pseudomonas reactans) and a bacterial endophyte (Pantoea ananatis). Plant biomass was assessed at harvest and differences between treatments were analysed. As the work also aimed to relate the effects of bioinoculation to alterations in plant response to salt stress, further parameters were assessed. Elevated salt levels induce ionic stress, with consequent nutrient imbalance; therefore, levels of Na, K and Ca were determined in plant tissues. As salt is also a major stress to soil organisms, rhizosphere samples were analysed to follow up of microbiota survival by molecular biology techniques (DGGE), assessing the effect of soil salinity at the different tested levels on the inoculated soil microorganisms persistence and relationship with the existing community. The collected information allowed understanding the effects of the applied biologically based treatments in the quality of the tested saline soils, on the dynamics of the present microbiota and on maize growth, focusing on the further development of cropping strategies for saline soils, grounded on sustainable agriculture practices.
- Application of phytomanagement strategies in contaminated areas of the SUDOE spacePublication . Mench, Michel; Garbisu, Carlos; Epelde, Lur; Soussou, Souhir; Soto-Lopez, Manuel; Hernandez, Antonio; Dudoit, Laurent; Vilela, Juan; Castro, Paula; Moreira, Helena; Pereira, Sofia; Rodríguez-Garrido, Beatriz; Prieto-Fernandez, Angeles; Monterroso-Martínez, Carmen; Cardoso, Eduardo; Jouveau, Séverin; Burlett, Régis; Delzon, Sylvain; Albareda, Aroa; Sousa, Álvaro Nunes de; Becerril, Jose Maria; Segura, Raphael
- Approach to phytotechnology regulatory and market trends in Europe: future perspectivesPublication . Vega, Alberto; Pereira, Sofia I. A.; Moreira, Helena; Ávila, Paula; Ferreira, Adelaide; Castro, Paula M. L.
- Arsenic, lead and nickel accumulation in Rubus ulmifolius growing in contaminated soil in PortugalPublication . Marques, Ana P. G. C.; Moreira, Helena; Rangel, António O.S.S.; Castro, Paula M.L.This work investigates the potential of Rubus ulmifolius, indigenous to ametal contaminated site – Esteiro de Estarreja – for phytoremediation purposes. The site has a long history of metal contamination. The accumulation of lead (Pb), arsenic (As) and nickel (Ni) in different sections – roots, stems and leaves – of the plant was assessed and compared to the levels of those metals in the soil and in the available fraction. The distribution of metals throughout the area was quite heterogeneous, presenting levels of As, Pb and Ni of up to 3078, 1400 and 135mg kg¯¹, respectively, and the metal content in the sections of R. ulmifolius collected in the banks of the stream varied among sites of collection. Levels of metals were higher in the plant roots: As levels (mg kg¯¹) ranged from 277 to 1721 in the roots, 30 to 110 in the stems, and 60 to 265 in the leaves; Pb concentrations (mg kg¯¹) ranged from 248 to 1178 in the roots, 35 to 133 in the stems, and 25 to 149 in the leaves; and Ni (mg kg¯¹) ranged from 48 to 151 in the roots. Significant correlations were found between the total levels of Pb and As in the soil and the levels in the roots of the plant; further correlations between total and available levels in the soil and metals in other plant tissues were generally found as non-significant. According to the metal accumulation patterns of R. ulmifolius, this species seems to be valuable for application in phytostabilisation strategies.
- Assessment of metal(loid)s phytoavailability in mining soilsPublication . Ávila, Paula F.; Ferreira, Adelaide; Moreira, Helena; Pereira, Sofia I. A.; Vega, Alberto; Candeias, Carla; Castro, Paula M. L.
- Assessment of metalloids phytoavailability in mining soilsPublication . Ávila, Paula F.; Ferreira, Adelaide; Moreira, Helena; Pereira, Sofia I. A.; Vega, Alberto; Candeias, Carla; Castro, Paula M. L.
- Assessment of metallophytes diversity in a metal(loid) contaminated Portuguese mine for phytotechnological purposesPublication . Sousa, Ana S. S.; Pereira, Sofia I. A.; Cunha, Joaquim; Vila-Viçosa, Carlos; Castro, Paula M. L.; Moreira, Helena
- Assessment of the plant growth promotion abilities of six bacterial isolates using Zea mays as indicator plantPublication . Marques, Ana P. G. C.; Pires, Carlos; Moreira, Helena; Rangel, António O. S. S.; Castro, Paula M. L.Zea mays, one of the most important cereals worldwide, is a plant not only with food and energy value, but also with phytoremediation potential. The use of plant growth promoting (PGP) rhizobacteria may constitute a biological alternative to increase crop yield and plant resistance to degraded environments. In search for PGP rhizobacteria strains, 6 bacterial isolates were isolated from a metal contaminated site, screened in vitro for their PGP characteristics and their effects on the growth of Z. mays were assessed. Isolates were identified as 3A10T, ECP37T, corresponding to Chryseobacterium palustre and Chryseobacterium humi, and 1ZP4, EC15, EC30 and 1C2, corresponding to strains within the genera Sphingobacterium, Bacillus, Achromobacter, and Ralstonia, respectively. All the bacterial isolates were shown to produce indole acetic acid, hydrogen cyanide and ammonia when tested in vitro for their plant growth promoting abilities, but only isolates 1C2, 1ZP4 and ECP37T have shown siderophore production. Their further application in a greenhouse experiment using Z. mays indicated that plant traits such as root and shoot elongation and biomass production, and nutrient status, namely N and P levels, were influenced by the inoculation, with plants inoculated with 1C2 generally outperforming the other treatments. Two other bacterial isolates, 1ZP4 and ECP37T also led to increased plant growth in the greenhouse. These 3 species, corresponding to strains within the genera Ralstonia (1C2), Sphingobacterium (1ZP4), and to a strain identified as C. humi (ECP37T) can thus be potential agents to increase crop yield in maize plants.
- Bacterial and macro/mesofauna diversity of a Portuguese mine tailingPublication . Sousa, Ana S. S.; Pereira, Sofia I. A.; Moreira, Helena; Cunha, Joaquim; Nunes de Sousa, Álvaro; Natal-Luz, Tiago; Tentugal, Rita; Alves, Daniela; Castro, Paula M. L.
- Bio-based superabsorbent hydrogels for nutrient releasePublication . Ribeiro, Alessandra B.; Moreira, Helena; Pereira, Sofia I. A.; Godinho, Mariana; Sousa, Ana Sofia da Silva; Castro, Paula; Pereira, Carla F.; Casanova, Francisca; Freixo, Ricardo; Pintado, Manuela E.; Ramos, Óscar L.Drought is characterized by a low water precipitation rate, with strong impact on crop productivity, threatening global food production. In this context, the use of soil amendments, such as superabsorbent hydrogels constitute a potential technology for better water use efficiency and higher crop yields. In this work, we synthesised cellulose-based hydrogels, characterized their physical and functional properties, evaluated their impact on the environment, and their potential to be used as a soil amendments. The hydrogel showed pH of 6.0 to 7.5 and conductivity below 10.0 µS cm-1. The Fourier-transform infrared spectroscopy (FTIR) showed a low intensity peak in the crystallinity region, which was supported by the low crystallinity index (27.3% ± 0.6) verified by Powder X-ray diffraction (PXRD) analysis. The swelling capacity reached more than 200 g of water, the hydrogel showed good resistance to osmotic pressure and high thermostability, which favours the application in hot and arid areas. In addition, no potentially hazardous compound was detected, nor was there any adverse effect on soil microorganisms. Further, the hydrogel was found to be safe for use during seed sowing and for promoting seedling development. In the greenhouse pot experiment, the hydrogels showed a significant increase in maize shoot and root biomass, demonstrating their ability to contribute to the overall water holding capacity of the soil, thereby influencing nutrient availability for more efficient plant growth. In conclusion, the superabsorbent hydrogel exhibited promising characteristics for use as a soil amendment, scalability potential and constitutes a sustainable alternative for agricultural applications.