Relation between sorghum root system and aluminium toxicity

Abstract

The effects of different concentrations of aluminium and pH on Sorghum dochna seed growth and mineral nutrition have been studied. An acid nutritive solution favours absorption of oligoelements and calcium, whereas a basic medium promotes uptake of phosphorus, nitrogen, magnesium and potassium. Moreover, aluminium whether absorbed by seminal roots or adventitious roots has a strong inhibitory effect on calcium, independant of pH. The marked sensitivity of the plant to Al⁺⁺⁺ ions more than H⁺ ions is explainable by the localization of calcium and lipids which are only slightly membrane bound in adventitious roots, and by the low intracellular chelating capacity of organic acids for the trivalent element.

Key words:

• Adventitious and seminal roots
• aluminium toxicity
• organic acids
• Sorghum dochna