Toxicidade de cádmio em diferentes cultivares de soja

Abstract

Soybean (Glycine max (L.) Merrill) stands out in the world, as one of the most economically important crops. Trace elements (TEs) such as cadmium (Cd) can be absorbed by plants and incorporated into food chains, bringing risks to exposed organisms. The objective was to evaluate the toxicity of Cd in soybean cultivars with different maturation cycles (early, medium and late). The experiment was carried out in a greenhouse where the different cultivars were submitted to Cd toxicity. TE doses were added to the soybean seeds, where germination, plant height (PH), root length (RL), mass fresh aerial and root (MFA and MFR) and dry aerial and root mass (DA and DR) The design used was completely randomized, in a 3x11 factorial scheme (3 doses of Cd, 0, 2.5 and 5.0 μg L -1 and 11 cultivars) with 3 replicates. The results were submitted to ANAVA and tested by the ScottKnott test at 5% probability, if a significant difference was observed. In addition to classical statistical analysis, principal component analysis (PCA) was performed. The presence of the trace element Cd affected the germination of soybean cultivars. The cultivars of late maturation cycle suffered an effect in the higher dose 5.0 µg L-1 of Cd, while those of early and medium cycle were affected in the dose 2.5µg L-1 of the element. The cultivar SYN 13671 showed the greatest losses in development due to exposure to Cd. The cultivars without exposure to Cd showed similar behaviors, grouping in the positive parts of main components 1 and 2, ranging from 0 to 5 positive. At the dose of 2.5 μg L-1 , there was no clustering and for the dose of 5.0 μg L-1 , the cultivars showed medium clustering. It is concluded that the presence of cadmium affects the majority of soybean cultivars marketed, and may cause damage to the crop.