Abstract

BELTRAN-DAVALOS, Andrés Agustín; ROSERO-ERAZO, Carlos; CARGUA-CATAGNA, Franklin  and  ECHEVERRIA, Magdy. Potential of Zantedeschia aethiopica L. for rehabilitation of soil contaminated with hexavalent chromium in high Andean areas of Ecuador. Acta Agron. [online]. 2019, vol.68, n.2, pp.92-98. ISSN 0120-2812.  https://doi.org/10.15446/acag.v68n2.77859.

Zantedeschia aethiopica is one of the ornamental vascular plants, protective of wetlands and fluvial systems with greater distribution in the Andean zone of Ecuador. The objective of the research was to evaluate the toxic effect of Chromium VI in Zantedeschia aethiopica L. recognizing its limitations as a bioindicator plant, for which specific and non-specific physiological effects were determined such as relative seed germination (RSG), root elongation relative (ERR) and germination index in experimental units exposed to concentrations of 0, 50, 100, 200 and 300 mg.kg-1 of Cr+6 during 168 hours; then monitoring the growth of the plant grown in contaminated soil under the concentrations of the germination stage under semi-controlled conditions of temperature, humidity and field capacity for 20 weeks; in the postharvest, analysis of the concentrations of the metal in the aerial zone of the plant (stem, leaves, and flowers) and root were carried out for the determination of the translocation index (TI) and soil for the evaluation of the Bioconcentration Factor (BCF). The results indicated the toxicity of Cr+6 in concentrations of 100, 200 and 300 mg.kg-1 with similar statistical behavior (P<0,05) in the germination stage and with non-specific physiological effects on the growth of the plant at concentrations of 200 and 300 mg.kg-1 showing absent flowering, dwarfing and wilting. With the obtained results and applying a bivariate Probit statistical analysis with a 95% reliability, the LC50 was determined in 118.96 mg.kg-1 of Cr+6 limit in which the plant can be a bioaccumulative and bioindicator species at concentrations higher than 200 mg.kg-1.

Keywords : Relative radicular elongation; hexavalent chromium; germination index; Zantedeschia aethiopica L.; Bioconcentration factor (BFC).

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