TY - JOUR
T1 - Cadmium phytoextraction by Helianthus annuus (sunflower), Brassica napus cv Wichita (rapeseed), and Chyrsopogon zizanioides (vetiver)
AU - Benavides, Bolaños J.
AU - Drohan, P. J.
AU - Spargo, J. T.
AU - Maximova, S. N.
AU - Guiltinan, M. J.
AU - Miller, D. A.
N1 - Funding Information:
This work was supported by: The Pennsylvania State University, College of Agricultural Sciences; the Penn State Endowed Program in Molecular Biology of Cacao; USDA-FAS Cacao for Peace Agreement TA-CR-16-028; and by the USDA National Institute of Food and Agriculture , Federal Appropriations under Project PEN04569 and Accession number 1003147. Special thanks go to Dr. Rufus Chaney for comments and suggested revisions.
Funding Information:
The use of phytoextraction plant species to accumulate soil metals into harvestable plant parts is a method used for managing soils with high cadmium (Cd). We evaluated three Cd accumulating species recently recommended for such use in cacao farms where Cd removal is needed to maintain markets: Helianthus annuus (sunflower), Brassica napus (rapeseed), and Chyrsopogon zizanioides (vetiver). Plants were grown in two greenhouse pot experiments with different Cd-spiked growth media: (sand plus perlite) and a natural soil. Plant total Cd and Cd uptake in shoot biomass of all species, across both experiments, increased linearly with increasing amounts of added Cd. Rapeseed had the highest plant total Cd and sunflower had the highest Cd uptake in shoot biomass. The highest application of Cd corresponded to the highest plant total Cd and shoot biomass Cd uptake, regardless of species. The bioconcentration factor (BCF) for each species increased in a curvilinear manner with added Cd, with maximum BCF values for plants grown in the sand and perlite matrix at 2.5 mg kg?1 added Cd and in the natural soil at 5.0 mg kg?1 added Cd. We conclude that the Cd uptake (shoot biomass only) capability of the three species examined is greatest for sunflower given its increased uptake with Cd additions, its BCF value > 1, and lack of observed visual Cd toxicity symptoms, fungus and insect damage. Although these species had BCF >1, the potential annual removal of Cd would have been too small to support a meaningful phytoextraction practice.The range in BCF values found in our study species versus other studies suggests that a difficulty exists for researchers or land managers when interpreting BCFs for the purpose of identifying potential phytoextraction species. First, Cd BCF values for different species exhibit a range of values when grown in polluted matrices: e.g. Pinus pinaster was 1.85 (Andras et al., 2016); carrot 0.62 (Yang et al., 2009); cucumber 4.8 (Li et al., 2017); potato 0.28 (Swartjes et al., 2013); spinach 2.29 (Swartjes et al., 2013); rice 1.11 (Song et al., 2015); and corn 0.16 (Hamidpour et al., 2010). In addition, within species BCF values vary. K?tschau et al. (2014) suggests that a plant's BCF may increase or decrease depending on biotic and abiotic (soil pH) conditions, especially when grown with other plant species. Changing BCF values of a plant grown with other species might ultimately change the bioavailability of Cd in soil over time; this point is supported by the comparison of our data to other studies using the same plant species. More concerning is the wide range in values for any one species (as found in our study versus others) and what this means in terms of using BCF as a variable to rank pollutant uptake potential. Perhaps the use of BCF is simply a relative one in any situation with absolute values not relatable between different studies using different extractions, growing media, and growing conditions?This work was supported by: The Pennsylvania State University, College of Agricultural Sciences; the Penn State Endowed Program in Molecular Biology of Cacao; USDA-FAS Cacao for Peace Agreement TA-CR-16-028; and by the USDA National Institute of Food and Agriculture, Federal Appropriations under Project PEN04569 and Accession number 1003147. Special thanks go to Dr. Rufus Chaney for comments and suggested revisions.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/2
Y1 - 2021/2
N2 - The use of phytoextraction plant species to accumulate soil metals into harvestable plant parts is a method used for managing soils with high cadmium (Cd). We evaluated three Cd accumulating species recently recommended for such use in cacao farms where Cd removal is needed to maintain markets: Helianthus annuus (sunflower), Brassica napus (rapeseed), and Chyrsopogon zizanioides (vetiver). Plants were grown in two greenhouse pot experiments with different Cd-spiked growth media: (sand plus perlite) and a natural soil. Plant total Cd and Cd uptake in shoot biomass of all species, across both experiments, increased linearly with increasing amounts of added Cd. Rapeseed had the highest plant total Cd and sunflower had the highest Cd uptake in shoot biomass. The highest application of Cd corresponded to the highest plant total Cd and shoot biomass Cd uptake, regardless of species. The bioconcentration factor (BCF) for each species increased in a curvilinear manner with added Cd, with maximum BCF values for plants grown in the sand and perlite matrix at 2.5 mg kg−1 added Cd and in the natural soil at 5.0 mg kg−1 added Cd. We conclude that the Cd uptake (shoot biomass only) capability of the three species examined is greatest for sunflower given its increased uptake with Cd additions, its BCF value > 1, and lack of observed visual Cd toxicity symptoms, fungus and insect damage. Although these species had BCF >1, the potential annual removal of Cd would have been too small to support a meaningful phytoextraction practice.
AB - The use of phytoextraction plant species to accumulate soil metals into harvestable plant parts is a method used for managing soils with high cadmium (Cd). We evaluated three Cd accumulating species recently recommended for such use in cacao farms where Cd removal is needed to maintain markets: Helianthus annuus (sunflower), Brassica napus (rapeseed), and Chyrsopogon zizanioides (vetiver). Plants were grown in two greenhouse pot experiments with different Cd-spiked growth media: (sand plus perlite) and a natural soil. Plant total Cd and Cd uptake in shoot biomass of all species, across both experiments, increased linearly with increasing amounts of added Cd. Rapeseed had the highest plant total Cd and sunflower had the highest Cd uptake in shoot biomass. The highest application of Cd corresponded to the highest plant total Cd and shoot biomass Cd uptake, regardless of species. The bioconcentration factor (BCF) for each species increased in a curvilinear manner with added Cd, with maximum BCF values for plants grown in the sand and perlite matrix at 2.5 mg kg−1 added Cd and in the natural soil at 5.0 mg kg−1 added Cd. We conclude that the Cd uptake (shoot biomass only) capability of the three species examined is greatest for sunflower given its increased uptake with Cd additions, its BCF value > 1, and lack of observed visual Cd toxicity symptoms, fungus and insect damage. Although these species had BCF >1, the potential annual removal of Cd would have been too small to support a meaningful phytoextraction practice.
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U2 - 10.1016/j.chemosphere.2020.129086
DO - 10.1016/j.chemosphere.2020.129086
M3 - Article
C2 - 33340834
AN - SCOPUS:85097870811
SN - 0045-6535
VL - 265
JO - Chemosphere
JF - Chemosphere
M1 - 129086
ER -