Efeito tóxico do sulfato de níquel em plântulas de Cereus jamacaru DC (Cactaceae)

Abstract

Nickel (Ni) is a naturally occurring internal transition metal in terrestrial areas and widely extracted and used in the metal and electronic industries. Lately, there has been a significant increase in this toxic element in ecosystems due to anthropogenic actions, making it highly persistent in the environment. Although it is a micronutrient for plants and microorganisms, Ni in high concentrations induces toxic effects on plants. Therefore, it is important to evaluate the effects of this toxicity on plants important for maintaining the biodiversity of your region, in addition to its use for man in different economic areas, such as veterinarian, doctor, food and chemistry. Cereus jamacaru is an endemic cactus native to the Caatinga and widely used in this region for various purposes. In this work, we sought to evaluate the toxicity of nickel in different concentrations on seedlings of C. jamacaru. Toxicity tests were performed with different concentrations (0.0; 0.1; 0.5; 1.0; 5.0 and 10 mM) of nickel sulfate (NiSO4), which were applied to mandacaru seeds sown in petri dishes. To evaluate the toxic effect, germination, biometric parameters (length and integrity of seedling organs), physiological (chlorophylls and carotenoids) and anatomical parameters were evaluated. In all concentrations tested, Ni proved to be toxic to seedlings, varying between the parameters analyzed and leading to the death of the individual in the highest concentrations (5 and 10 mM).