Licielo Romero Vieira

Avaliação da atividade moluscicida de extratos vegetais sobre Achatina fulica Bowdich (Mollusca, Achatinidae)

Achatina fulica Bowdich (Achatinidae) is a terrestrial pulmonary gastropod that has become a pest in small subsistence plantations. Also it is considered as a threat to sustainable agriculture in some countries, which demand high investments in order to control it; however, the most part of the tried methods have failed. This species can also act as an intermediate host of nematodes. In this context, the search for compounds easily biodegradable has increased the interest for using molluscicidal agents obtained from plant sources. Therefore, this study aimed to evaluate leaves extracts of Bacharis dracunculifolia DC., Morus rubra L., Cyperus rotundus L. and buds extracts of Euphorbia heterophylla L. and Sygygium aromaticum (L.) Merr. & Perry as possible molluscicidal agents. From these species, S. aromaticum and E. heterophylla were active as molluscicidal agents affecting survival rate of A. fulica and, C. rotundus did not show molluscicidal activity over this gastropod. None of the plant species tested showed ovicidal activity. The results of the present study indicate that the aqueous extracts of S. aromaticum buds and E. heterophylla leaves can be a viable approach for alternative control of terrestrial molluscs.

CADMIUM TOXICITY IN PLANTS

Phytoremediation is a technique that uses plants for decontaminating polluted areas, as soil and water, especially from heavy metals and organic contaminants, reducing their concentration to safe levels. In addition, it contributes to improve physical, chemical and biological characteristics of these areas. Among the several forms of environmental contamination resulted from industrial and agricultural activities, water contamination with heavy metals has been the one causing more concern to researchers and government institutions involved to pollution control. Cadmium (Cd) is one of the heavy metals more studied due to its high toxicity to plants and animals. In response to the stress caused by Cd, plants can develop many tolerance mechanisms which can operate sometimes as additional mechanisms. Two possible mechanisms can be the activation of the antioxidant system and/or changes in sulfur metabolism, specially glutathione, an essential substrate to phytochelatins (PC) biosynthesis. Rivers and dams have been being contaminated with heavy metals and other contamination forms due to urban and industrial discharges. Part of heavy metal elimination and/or contamination detection can be done using aquatic plants as Eichhornia crassipes (Mart.) Solms and Salvinia auriculata (Aubl.).