Influence of phosphate and hydroxyl ions on aluminum toxicity in sorghum and wheat

Aluminum (Al) toxicity to plants in complete nutrient solutions is difficult to relate to Al activity in solution because of precipitation and complexation. Aluminum toxicity was studied for two seedling crops, sorghum (Sorghum bicolor L. Moench) and wheat (Triticum aestivum L. em Thell), at low lev...

Full description

Saved in:
Bibliographic Details
Published inJournal of plant nutrition Vol. 17; no. 2/3
Main Authors Shuman, L.M, Wilson, D.O
Format Journal Article
LanguageEnglish
Published 1994
Subjects
ALUMINIO
ALUMINIUM
ANION
ANIONES
CHLORURE DE CALCIUM
CLORURO CALCICO
CRECIMIENTO
CROISSANCE
FITOTOXICIDAD
FOSFORO
NITRATE DE POTASSIUM
NITRATO DE POTASIO
PHOSPHORE
PHYTOTOXICITE
RACINE
RAICES
SOLUCIONES NUTRITIVAS
SOLUTION NUTRITIVE
SORGHUM BICOLOR
TRITICUM AESTIVUM
Online AccessGet more information

Cover

More Information
Summary:Aluminum (Al) toxicity to plants in complete nutrient solutions is difficult to relate to Al activity in solution because of precipitation and complexation. Aluminum toxicity was studied for two seedling crops, sorghum (Sorghum bicolor L. Moench) and wheat (Triticum aestivum L. em Thell), at low levels (less than or equal to 10 micromolar) in two incomplete nutrient solutions to study plant response to Al alone, Al+PO4(3-), Al+OH-, and Al+PO4(3-)+OH-. Relative root length was the bioassay for Al toxicity. 'Monomeric' Al was measured using Aluminon and both root length and measured Al were compared to the theoretical Al in solution predicted by the MINTEQA2 equilibrium model. Low levels of Al were toxic to plant roots with sorghum showing a decrease in relative root length from 1 to 10 micromolar Al, and wheat showing a decrease from 4 to 10 micromolar. A mono-salt background solution (400 micromolar CaCl2) and a more complex base solution (CaCl2, KNO3, and MgCl2) gave similar root lengths and measured Al values. Phosphate and hydroxyl ameliorated Al toxicity and lowered measured Al in solution, but not to the extent predicted by the model. Adding phosphate (PO4(3-)) or hydroxyl (OH-) raised the pH, but again not as high as the model predicted. The difference in toxicity and measured Al were most likely the result of polymers (Al(+3)) which are toxic, but not measured by the procedure used, or included in the model which showed the Al as being removed from solution by precipitation
Bibliography:H50
9510939
ISSN:0190-4167
1532-4087