Application of multivariate analysis to evaluate the biochemical changes in sorghum (Sorghum bicolor L. Moench) after exposure to water stress and silicon applications

The objective of the present work was to verify, through multivariate analysis, the behavior patterns of biochemical compounds in forage sorghum, submitted to different silicon applications and water stress. Experiment with forage sorghum ( Sorghum bicolor L. Moench), variety BR 700, was conducted in a greenhouse. The experimental design was completely randomized in a 2×4 factorial arrangement with seven replicates, two hydric conditions (irrigated and water deficit) and four silicon applications (0.5, 1.0, 1.5 and 2.0 μM). The multivariate analysis showed that when there is no shortage of water and regardless of the silicon dose, nitrate levels were higher and carbohydrate, proline and sucrose levels were lower in leaves and roots. The quantity of biochemical compounds differed between sorghum leaves and roots. This condition also varied according to the soil water stress. Silicon application in sorghum plants mitigates the negative effect of drought stress, favoring this crop cultivation in areas of low water availability. Nonetheless, differences between silicon doses were not observed in this experiment. Therefore, it is recommended that this chemical should be applied in drought-ridden areas. Keywords: Water stress, proline, multivariate analysis, principal component analysis