Study of different parameters for evaluating Al tolerance in plants

Relative root elongation, Al content and callose content in root tips and hematoxylin staining were compared in evaluating plants’ tolerance of Al stress. The results showed that each of the three selected parameters varied among different plants or cultivars, and they could reflect the degree of Al tolerance in plants to some extent, especially among different cultivars in the same plant. Hematoxylin staining could qualitatively differentiate the Al accumulation in root tips. Relative root elongation is generally considered as a simple and common approach in evaluation of Al tolerance in plants, but sometimes it did not work very well. Al content and callose content in root tips could be good alternatives or supplemental methods for evaluating the degree of Al tolerance among plants.