Effect of nitrogen sources on aluminum toxicity in wheat varieties differing in tolerance to aluminum

Abstract

Extract As previously reported (Taylor and Foy 1985; Keltjens and Ulden 1987; Grauer and Horst 1990; Galvez and Clark 1991), plant species and varieties widely differ in Al tolerance. Although many hypotheses about the physiological mechanism(s) involved in Al tolerance have been formulated, the mechanism(s) has not been elucidated. However, it is obvious that when exposed to Al at high concentrations, Al-tolerant plants seem to be able to avoid the toxicity by refraining from excess uptake of Al or by chelating of Al in the rhizosphere or in the roots. In such ways, Al can not affect the growth of tolerant plants (Foy et al. 1978). © 1996 Taylor & Francis Group, LLC.