NonEDTA extractable Scandium in roots of three sorghum cultivars

Abstract

Scandium (Sc³⁺) is a rare earth whose uptake and physiological function mimics Al³⁺. In sorghum [Sorghum bicolor (L.) Moench.] root tips (1 cm), nonextractable (water and EDTA (15 mM)] Sc³⁺ (1 mM) increased as the pH of the growing medium decreased (pH 6.0 . pH 4.0) in Funk G522DR (an add soil stress sensitive cultivar). Nonextractable Sc³⁺ did not increase in root tips of the two acid soil stress tolerant cultivars SC574 and SC283. Water extractable Sc³⁺ varied by genotype and was SC 283 ≥ SC574 > Funk G522DR. These short term (10 min) sorption studies show a major pH influence on Sc³⁺ content of Funk G522DR, but not in SC283 and SC574 that cannot be due to mucigel contents.