Evaluación en laboratorio de la capacidad bioacumuladora de cromo hexavalente en lactuca sativa l. (lechuga) y beta vulgaris var. cicla (acelga) en etapa temprana de crecimiento

Abstract

In this research, the capacity of Lactuca sativa L. (lettuce) and Beta vulgaris var. cicla (chard) to bioaccumulate hexavalent chromium Cr+6. For this, five treatments were tested at different concentrations (2, 4, 6, and 8) ppm from K2Cr2O7 and a control of 0ppm each with six repetitions applying a completely randomised bifactorial design. Germination was carried out in Petri dishes based on a protocol established in 120 hours and early growth in the greenhouse, where thermal containers were used as pots. In this stage, the conditioning of the substrate was carried out, followed by the sowing of seeds and, later, the dosage (40 mL) of each treatment for two months. The samples were analysed through UV spectrophotometry; InfoStat 2020 was used to compare data statistically. As a result, the relative percentage of germination (%GRS) at eight ppm was 90% in lettuce and 30% in chard; that of the control was 100% and 71,67%, respectively the chard seeds presented a high sensitivity to metal. In addition, in the root length at eight ppm, a value of 3,68 cm was recorded for chard and 2,58 cm for lettuce at the same treatment, indicating the most significant sensitivity in its development. Regarding the germination index (IG), lettuce registered 68,33% and chard 50,97%, so it is concluded that both species presented moderate phytotoxicity. It is recommended to analyse the parts of the plant separately to determine if Chromium VI is accumulated in leaves and roots to estimate the exact Phyto concentration extracted by the plants.