128 research outputs found
Biofortification of Lettuce and Basil Seedlings to Produce Selenium Enriched Leafy Vegetables
Selenium (Se) biofortification of plants has been recognized as a good strategy to improve the nutritive value of vegetables and increase Se daily intake in humans. Identifying the most appropriate method to enrich plants is a key issue in the biofortification process. We tested a biofortification technique that produces Se enriched seedlings for transplant, yet barely modifies conventional cultivation techniques. Lettuce (Lactuca sativa L.) and sweet basil (Ocimum basilicum L.) were exposed to selenium by adding 0, 1 and 3 mg Lâ1 (lettuce) and 0, 2 and 3 mg Lâ1 (basil) of Se, as sodium selenate, to the growing substrate immediately after sowing. When seedlings reached an appropriate size, they were transplanted into the open field, and plants were grown until maturity. Lettuce and basil seedlings accumulated selenium without any reduction in leaf biomass at maturity. The highest dose of Se induced a higher antioxidant capacity and flavonoid content in both species at both sampling times. At maturity, biofortified plants still showed a higher leaf Se content compared to the control, and would be able to provide from 10% to 17% (lettuce) and from 9% to 12% (basil) of the adequate intake (AI) of Se
Influence of zinc and manganese enrichments on growth, biosorption and photosynthetic efficiency of Chlorella sp
Treating biosolids from industrial, urban, and agricultural plants produces high amounts of water. After organic pollutants and non-essential heavy metals have been removed, these wastewaters are still rich in trace elements such as zinc (Zn), copper, or manganese (Mn) and have high conductivity and extremely variable pH. In this study, an isolated Chlorella sp. strain was grown for 21 days in nutrient solutions enriched with known amounts of Zn or Mn to obtain concentrations three (4.0 mg Lâ1)- and six (1.0 mg Lâ1)-fold higher than the basal medium levels, respectively, and over the limits permitted in aquatic environments. The green alga exhibited high tolerance to Zn and Mn, with the maximum abatement of Zn (28â30%) and Mn (60â63.5%) after 14 and 7 days of culture, respectively. Mn stimulated the growth rate and biomass production of Chlorella, which showed the highest carbon levels just in the first week. In both treatments, the nitrogen and protein contents remarkably increased. The photosynthetic pigments increased until the 14th day, with a higher extent in the Zn-enriched solution. An increasing photochemical efficiency was observed after 7 days of treatment, when the microalgae grown in Zn- and Mn-enriched solutions showed a slightly higher maximum photochemical efficiency than control. The autotrophic and controlled growth system adopted was designed to monitor the dynamic balance of Zn and Mn contents in the solutions and in the algal biomass. This system has proved to be useful in identifying the optimal nutritional conditions of the microalgae, along with the optimal temporal patterns of both metal biosorption capacity for water remediation and element bioaccumulation in the algal biomass
Effects of Selenium Enrichment of Tomato Plants on Ripe Fruit Metabolism and Composition
The effects of selenium (Se) addition on production and quality traits of Solanum lycopersicon âRed Bunchâ were investigated. Se was added as sodium selenate at the rate of 0, 0.5 and 1 mg Se L-1 to the nutrient solution. Se was absorbed by roots and accumulated in leaves and fruits, and at the tested concentrations, it did not affect yield. Se concentration followed a gradient, decreasing from the basal
to the apical part of the plant. At red ripe stage, the fruits on the lower trusses accumulated higher amount of Se than the fruits of the higher trusses. Ă-carotene and lutein significantly decreased only at 1.0 mg Se L-1. Lycopene increased either in 0.5 and, less markedly, 1.0 mg Se L-1-treated fruits where a pronounced increase in quercetin was also observed
The distributions of the six species constituting the smooth newt species complex (Lissotriton vulgaris sensu lato and L. montandoni) â an addition to the New Atlas of Amphibians and Reptiles of Europe
The âsmooth newtâ, the taxon traditionally referred to as Lissotriton vulgaris,
consists of multiple morphologically distinct taxa. Given the uncertainty concerning the
validity and rank of these taxa, L. vulgaris sensu lato has often been treated as a single,
polytypic species. A recent study, driven by genetic data, proposed to recognize five species,
L. graecus, L. kosswigi, L. lantzi, L. schmidtleri and a more restricted L. vulgaris. The
Carpathian newt L. montandoni was confirmed to be a closely related sister species. We
propose to refer to this collective of six Lissotriton species as the smooth newt or Lissotriton
vulgaris species complex. Guided by comprehensive genomic data from throughout the range
of the smooth newt species complex we 1) delineate the distribution ranges, 2) provide a
distribution database, and 3) produce distribution maps according to the format of the New
Atlas of Amphibians and Reptiles of Europe, for the six constituent species. This allows us to
4) highlight regions where more research is needed to determine the position of contact zones
Ionic strentgh influence on heavy metal sorption processes by soil
The sorption of Cd and Cu by three different European soils was studied in the presence of increasing
concentration of CaCl. Cd sorption fitted the Freundlich equation, while Cu fitted the Langmuir equation.
Increasing ionic strength decreased the sorption of both metals, due to the competition of Ca ions for the sorption
sites in the soils. The influence of ionic strength was related to the mechanisms of heavy metal sorption by the soil.
The effect of increasing ionic strength was inversely related to organic matter content in soil
- âŠ