Efeito da toxicidade de boro em plantas de Solanum sessiliflorum (Dunal)

Abstract

The importance of Boron in plant nutrition has been well documented since the 1920s with experiments demonstrating that the absence of this element resulted in reduced growth of the entire plant. Therefore, boron has been classified as an essential mineral nutrient. That is, a nutrient in which, when absent, the plant is not able to complete its life cycle. Although it is a trace element, that is, required by plants in very low concentrations, boron has a narrow concentration range between its deficiency and toxicity. Keeping in mind that Amazonian soils mostly have similar relative amounts of boron, but due to the very different pH found between these soils, the availability of boron to the plant can be altered, it is very common to find this element resulting in toxicity to the plant. Therefore, a fundamental question to be answered would be the effect of Boron on native Amazonian plants in order to know whether they are adapted and/or tolerant to nutritional stresses – in this case boron toxicity. In this sense, Solanum sessiliflorum, also known as cubiu, is a wild species belonging to the Solanaceae family. However, this species is still neglected in studies of plant physiology and ecophysiology. This scenario, in turn, has been gradually changing, showing the important ecophysiological relationships of this species. Convincing evidence has shown that the physicochemical characteristics of different types of soils in the Amazon region under the growth of cubiu plants suggest that boron appears to be a determining factor in the growth of cubiu in Amazonian soils. Thus, in an attempt to understand the impact of excess boron on plant growth, cubiu plants will be grown in a hydroponic medium supplemented with boron and the impact of this element's toxicity will be measured by morphophysiological assessments.