Resumo

ARMENDARIZ SAENZ, Nayeli Ismene et al. Evaluation of two biochemical parameters in three aquatic macrophytes exposed to copper. Polibotánica [online]. 2008, n.26, pp.149-158. ISSN 1405-2768.

Lake Patzcuaro in Michoacan, Mexico, continually receives influxes of wastewater, fertilizers and biocides. This circumstance has contributed to the rise of copper (Cu) within the water body. Although Cu is an essential micronutrient for plants, in high concentrations it is toxic, affecting their physiology and development. The objective of this work was to evaluate through colorimetric methods the content of chlorophylls and total free sugars, two response parameters or biomarkers, in three aquatic macrophytes that are common in Lake Patzcuaro: Eichhornia crassipes, Hydrocotyle ranunculoides y Lemna gibba. The results showed that both types of chlorophylls as well as the total free sugars varied in function with the increase in Cu within the nutritive solution; however, total free sugars were the most useful response parameter for detecting physiological changes in this bioassay.

Palavras-chave : chlorophyll; sugars; copper; biomarkers; aquatic macrophytes.