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Effects of glyphosate spray-drift on plant flowering
2021
Strandberg, B. | Sørensen, P.B. | Bruus, M. | Bossi, R. | Dupont, Y.L. | Link, M. | Damgaard, C.F.
Recent studies have shown that sub-lethal doses of herbicides may affect plant flowering, however, no study has established a direct relationship between the concentrations of deposited herbicide and plant flowering. Here the aim was to investigate the relationship between herbicide spray drift deposited on non-target plants and plant flowering in a realistic agro-ecosystem setting. The concentrations of the herbicide glyphosate deposited on plants were estimated by measuring the concentration of a dye tracer applied together with the herbicide. The estimated maximal and average deposition of glyphosate within the experimental area corresponded to 30 g glyphosate/ha (2.08% of the label rate of 1440 g a.i./ha) and 2.4 g glyphosate/ha (0.15% label rate), respectively, and the concentrations decreased rapidly with increasing distance from the spraying track. However, there were not a unique relation between distance and deposition, which indicate that heterogeneities of turbulence, wind speed and/or direction can strongly influence the deposition from 1 min to another during spraying. The effects of glyphosate on cumulative flower numbers and flowering time were modelled using Gompertz growth models on four non-target species. Glyphosate had a significantly negative effect on the cumulative number of flowers on Trifolium pratense and Lotus corniculatus, whereas there were no significant effects on Trifolium repens, and a positive, but non-significant, effect on number of flowers on Cichorium intybus. Glyphosate did not affect the flowering time of any of the four species significantly. Lack of floral resources is known to be of major importance for pollinator declines. The implications of the presented results for pesticide risk assessment are discussed.
Mostrar más [+] Menos [-]Effect of soil cadmium on root organic acid secretion by forage crops
2021
Ubeynarayana, Nilusha | Jeyakumar, Paramsothy | Bishop, Peter | Pereira, Roberto Calvelo | Anderson, Christopher W.N.
The two forage species used in New Zealand pastoral agricultural systems, chicory (Cichorium intybus) and plantain (Plantago lanceolata) show differential ability to absorb and translocate cadmium (Cd) from roots to shoots. Chicory can accumulate Cd from even low Cd soils to levels that might exceed regulatory guidelines for Cd in fodder crops and food. Chicory and plantain were grown in soil-filled rhizocolumns under increasing Cd levels (0 (Control), 0.4, 0.8 and 1.6 mg Cd/kg soil) for 60 days and showed variable secretion of oxalic, fumaric, malic and acetic acids as a function of Cd treatment. Plant roots secrete such Low Molecular Weight Organic Acids into the rhizosphere soil, which can influence Cd uptake. Chicory showed significantly (P < 0.05) lower secretion of fumaric acid, and higher secretion of acetic acid than plantain at all Cd treatments. We propose that the significant secretion differences between the two species can explain the significantly (P < 0.05) higher shoot Cd concentration in chicory for all Cd treatments. Understanding the mechanism for increased uptake in chicory may lead to breeding or genetic modification which yield low Cd uptake cultivars needed to mitigate the risk of Cd accumulation in pastoral agricultural food chains from this increasingly important fodder crop.
Mostrar más [+] Menos [-]Bioaccumulation of Heavy Metals by Herbaceous Species Grown in Urban and Rural Sites
2022
Pietrelli, Loris | Menegoni, Patrizia | Papetti, Patrizia
The ability of seven herbaceous species (Hypericum perforatum L., Dactylis glomerata L., Plantago lanceolata L., Verbascum thapsus L., Picris hieracioides L., Cichorium intybus L., Daucus carota L.) to accumulate heavy metals such as Cd, Cr, Cu, Ni, Pb, and Zn has been studied. The concentration of heavy metals was determined in roots, basal and cauline leaves, flowers, and stalks for each collected species. The species were selected according to their cosmopolitan characteristics, morphology, life cycle, and phenology. Soils and plants were collected from two sites: close to a high traffic road in the inner city of Rome and in a natural park north of Rome (Canale Monterano). The concentration of elements in soil in descending order were Zn>Pb>Cu>Ni>Cr>Cd, while the EDTA extractable element concentrations in the roots followed the sequence Zn>Cu≈Pb>Cd>Cr>Ni. The bioaccumulation factors (BF) and the transport factors (TF) were calculated for each plant species. Results showed a significant relationship between heavy metals content in soil and plant species. H. perforatum showed a high Pb accumulation capacity in the stalk (70.30 mg kg⁻¹) and roots (73.41 mg kg⁻¹); moreover, BF>1 for this species at urban site has been obtained. Plantago lanceolata and Dactlys glomerata have shown higher Cd absorption (BF=1.33 and 0.55 in rural and urban sites, respectively). Plantago lanceolata in general shows high heavy metal uptake. The distribution of metals within the plant strongly depends on the species; the main accumulation of Ni, Cd, and Cu was observed in the leaves, while the highest Cr concentration was observed in the flowers. Plant species can be effectively considered as valid bioindicators of heavy metals derived from human activities and can be used to monitor pollution changes in the environment.
Mostrar más [+] Menos [-]The use of some plant-derived products as effective alternatives to antibiotic growth promoters in organic poultry production: a review
2021
Seidavi, Alireza | Tavakoli, Masomeh | Slozhenkina, Marina | Gorlov, Ivan | Hashem, Nesrein M. | Asroosh, Fariborz | Taha, Ayman E. | Abd El-Hack, Mohamed E. | Swelum, Ayman A
Improving poultry production, increasing poultry immunity, and reducing the disease spreading can be achieved by adding various potentially valuable ingredients to the feed or drinking water of poultry flocks. Because of the emergence of antimicrobial resistance, antibiotic growth promoters (AGP) in animal nutrition were prohibited. Additionally, consumer preferences tend towards purchasing products from livestock raised without antibiotics. Therefore, there is a critical need to find effective growth promoter alternatives and treatment methods for common poultry diseases. Some spice plants play important roles in improving the taste, aroma, and color of human food and their positive effects on human and animal health. The current review aimed to provide a broader perspective on some spice crops which can be effective alternatives to antibiotics in organic poultry production. These spices were including Thymus vulgaris, Cichorium intybus, Coriandrum sativum, Aloe vera, Heracleum persicum, Curcuma longa, and Glycyrrhiza glabra.
Mostrar más [+] Menos [-]Nitric oxide and selenium nanoparticles confer changes in growth, metabolism, antioxidant machinery, gene expression, and flowering in chicory (Cichorium intybus L.): potential benefits and risk assessment
2021
Abedi, Sara | Iranbakhsh, Alireza | Oraghi Ardebili, Zahra | Ebadi, Mostafa
This experiment was conducted to provide a better insight into the plant responses to nitric oxide (NO) and selenium nanoparticle (nSe). Chicory seedlings were sprayed with nSe (0, 4, and 40 mg l⁻¹), and/or NO (0 and 25 μM). NO and/or nSe4 improved shoot and root biomass by an average of 32%. The nSe40 adversely influenced shoot and root biomass (mean = 26%), exhibiting moderate toxicity partly relieved by NO. The nSe and NO treatments transcriptionally stimulated the dehydration response element B1A (DREB1A) gene (mean = 29.6-fold). At the transcriptional level, nSe4 or NO moderately upregulated phenylalanine ammonia-lyase (PAL) and hydroxycinnamoyl-CoA quinate transferase (HCT1) genes (mean = sevenfold). The nSe4 + NO, nSe40, and nSe40 + NO groups drastically induced the expression of PAL and HCT1 genes (mean = 30-fold). With a similar trend, hydroxycinnamoyl-CoA Quinate/shikimate hydroxycinnamoyl transferase (HQT1) gene was also upregulated in response to nSe and/or NO (mean = 25-fold). The activities of nitrate reductase and catalase enzymes were also induced in the nSe- and/or NO-treated seedlings. Likewise, the application of these supplements associated with an increase in ascorbate concentration (mean = 31.5%) reduced glutathione (mean = 35%). NO and/or nSe enhanced the PAL activity (mean = 36.4%) and soluble phenols (mean = 40%). The flowering was also influenced by the supplements in dose and compound dependent manner exhibiting the long-time responses. It appears that the nSe-triggered signaling can associate with a plethora of developmental, physiological, and molecular responses at least in part via the fundamental regulatory roles of transcription factors, like DREB1A as one the most significant genes for conferring tolerance in crops.
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