title: Germination of Medicago sativa is inhibited by soluble compounds in cement dust.
abstract: Deposition of cement dust on soils and plant surfaces is known to affect plant growth and the species composition of plant communities, but little is known about its effects (and those of its pH and constituents) on germination. Therefore, the aim of this study was to assess the toxicity of an aqueous cement extract, constituents of the extract and pH on the germination of seeds of a selected species, Medicago sativa. First, the effects of the extract were tested in assays with concentrations and exposure durations ranging from 0 to 1.0 g/mL and 4 to 96 h, respectively. At 0.8 g/mL, the extract strongly inhibited germination; a 4-h exposure reduced the germination rate, from 77 ± 1.8 to 50 ± 2.6% (mean ± SE), while 8-h exposure completely inhibited it. Further, treatment at this concentration killed the non-germinating seeds, thus the inhibition was due to toxic effects. Neither the pH of the extract nor the concentration of its main soluble elements separately (K, Ca, S, Na, or Cr) caused the toxicity since germination rates were not significantly reduced when these variables were tested individually. However, a mixture of the elements in solution reduced germination rates, suggesting that they have adverse synergistic effects.
authors.affiliation: Instituto de Recursos Naturales y Agrobiología de Salamanca; Consejo Superior de Investigaciones Cientificas (IRNASA-CSIC), Cordel de Merinas 40-52, 37008, Salamanca, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Lafragüeta
authors.forename: Balbino
authors.initials: B
authors.lastname: García-Criado
authors.forename: Angel
authors.initials: A
authors.lastname: Arranz
authors.forename: Beatriz R
authors.initials: BR
authors.lastname: Vázquez-de-Aldana
mesh_terms: D003252:Construction Materials / Q000633:toxicity*; D004391:Dust / Q000032:analysis*; D004785:Environmental Pollutants / Q000633:toxicity; D018525:Germination / Q000187:drug effects*; D000455:Medicago sativa / Q000187:drug effects* / Q000502:physiology; D010944:Plants / Q000187:drug effects; D018570:Risk Assessment; D012987:Soil
chemical_list: D004391:Dust; D004785:Environmental Pollutants; D012987:Soil
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