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Cadmium and chromium uptake by Indian mustard Brassica juncea (L.) Czern metal-exposed since germination
No full textTo make phytoremediation a technically viable option for large-scale applications we need plants that are able to
guarantee high biomass yield as well as high accumulation of heavy metals in their aerial parts. The aim of this investigation
was to study the performance of aquacultured plants of Indian mustard in the presence of different concentrations
of cadmium and chromium since seed germination. The effects on germination and growth of seedlings
of Indian mustard (Brassica juncea L. Czern) cv. WNFP, Varuna and Barton, were investigated in/under hydroponic
conditions during a 4-week experiment. Cadmium and chromium were provided since germination as cadmium
nitrate Cd(NO3)2 and chromium bichromate K2Cr2O7 (0.5, 1 and 1.5 M). Plant biomass growth measured at the end
of the experiments varied with the different metal concentrations in the nutrient solution and the accumulation of
the elements in the plant fractions differed significantly among/between cultivars. Ability in the uptake of metals
and their mobilization and storage in the aerial plant biomass, expressed by the bioconcentration factor (BCF) and
translocation factor (TF), respectively, are the most important traits of plants with phytoextraction potential. Brassica
juncea was confirmed as being a highly tolerant species, but poor metal translocation values were registered,
therefore the high amount of Cd and Cr concentrated in the root systems did not migrate to the aerial, harvestable,
part of the plant
Phytoextraction of heavy metals by canola (Brassica napus) and radish (Raphanus sativus) grown on multicontaminated soil
No full textPhytoextraction can provide an effective in situ technique for removing heavy metals from polluted soils. The experiment
reported in this paper was undertaken to study the basic potential of phytoextraction of Brassica napus (canola) and Raphanus
sativus (radish) grown on a multi-metal contaminated soil in the framework of a pot-experiment. Chlorophyll contents and gas
exchanges were measured during the experiment; the heavy metal phytoextraction efficiency of canola and radish were also
determined and the phytoextraction coefficient for each metal calculated. Data indicated that both species are moderately tolerant to
heavy metals and that radish is more so than canola. These species showed relatively low phytoremediation potential of
multicontaminated soils. They could possibly be used with success in marginally polluted soils where their growth would not be
impaired and the extraction of heavy metals could be maintained at satisfying levels
Reclamation of polluted soils: potential for phytoremediation of crop-related Brassica species
No full textSoils polluted by heavy metals can be reclaimed using a number of expensive tactics
that either remove the contaminants or stabilize them within the soil. The value of metal
accumulating plants for environmental remediation has recently come to be appreciated and promising results have been obtained. This paper reports a study on the behavior of Brassica napus, Brassica juncea, Raphanus sativus and Brassica carinata grown on a substrate contaminated by several heavy metals caused by the use of contaminated irrigation water. Data on carbon dioxide assimilation, biomass growth and the bioconcentration and translocation factor of each metal in each species were measured.
The polluted substrate caused only a small variation in photosynthesis, however
transpiration was more affected by the experimental substrate and in all three species of the genus Brassica the presence of metals in the substrate resulted in higher
transpiration levels.
Two bioconcentration factors were calculated respectively for the roots (BCF) and the
shoots (BCF’); the BCF was >1 for all the species for Cd, Cu, Ni and Zn without
significant differences among species. All the values of BCF’ were lower than 0.5;
among the metals, all Brassica species demonstrated a similar performance for Cd and Zn, while for other elements the bioconcentration factor was very low
Germination performance of alien and native species could shape community assembly of temperate grasslands under different temperature scenarios
Full text linkRising temperatures due to climate change are expected to interplay with biological invasions, and may enhance the spread and growth of some alien species upon arrival in new areas. To successfully invade, a plant species needs to overcome multiple biological barriers. Among the crucial life stages, seed germination greatly contributes to the final species assembly of a plant community. Several studies have suggested that alien plant success is related to their high seed germination and longevity in the soil. Hence, our aim is to test if the germination potential of alien seeds present in the seed bank will be further enhanced by future warming in temperate dry grasslands, an ecosystem that is among those most prone to biological invasions. We designed a laboratory germination experiment at two temperatures (20 and 28 °C), to simulate an early or late heat wave in the growing season, using seeds from nine common grassland Asteraceae species, including native, archaeophyte and neophyte species. The test was performed on both single and mixed pools of these categories of species, using a full-factorial orthogonal design. The warmer germination temperature promoted neophyte success by increasing germination probability and germination speed, while negatively impacting these parameters in seeds of native species. The co-occurrence of native and archaeophyte seeds at the lower temperature limited the invasiveness of neophytes. These results provide important information on future management actions aimed at containing alien plant invasions, by improving our knowledge on the possible seed-bank response and interaction mechanisms of common species occurring in disturbed natural areas or restored sites. Graphical abstract: Summary of the experimental results. The colour of the flowers represent the status, divided as native (blue), neophyte (red) and archaeophyte (green). Each flower symbol represents the species pool for each plant category (i.e. NA = Buphthalmum salicifolium, Carlina vulgaris, Centaurea scabiosa; NE = Artemisia annua, Symphyotrichum novi-belgii, Senecio inaequidens; AR = Centaurea cyanus, Cichorium intybus, Tripleurospermum inodorum). The number of flowers represent the germination percentage of the various category assembly. In the columns are divided the various combination. From up to bottom the trend of germination percentage at 20 and 28 °C are shown. [Figure not available: see fulltext.]
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