Multispectral Imaging Related to Biochemical Parameters of Brazilian Mahogany (Swietenia macrophylla King) Exposed to Nickel

Objective: Due to this, this study aimed to evaluate the behavior of the normalized difference vegetation index (NDVI) correlating with leaf biochemical variables of Brazilian mahogany (Swietenia macrophylla) under the effect of increasing doses of nickel. Theoretical Framework: Multispectral analyses are a way to assess the early, efficient, unbiased, and, most importantly, non-destructive responses of plants subjected to stress. Method: The experimental design used was a randomized block design (RBD), with five treatments (0, 2, 4, 6 and 8 mg.L-1 of NiCl2.6H2O), with six replicates. The data set obtained was subjected to Pearson's correlation (1892) and multivariate analysis by principal components using the R-Studio-1.3.1093 software. Results and Discussion: The multispectral responses were quite distinct between control and stressed plants until the 30th day of exposure to nickel. The increase in chlorophylls was not accompanied by an increase in the production of photoassimilates, since although there was an increase in such pigments, they were possibly not at their potential operating capacity due to the nickel stress levels. Research Implications: In stress situations, mahogany plants tend to maintain NDVI with a relationship directly proportional to carbohydrates, on the other hand, variables such as leaf temperature, chlorophyll a, b and total tend to have an inversely proportional relationship. Originality/Value: Even though a considerable number of studies have demonstrated the toxicological effects and stress mechanisms caused by nickel in forest plants, there are still unknown parameters, such as the biochemical response related to vegetative index parameters. Therefore, there is a need to clarify many aspects addressed in this study.