Figure 2.

Differential manifestation of Al stress symptoms in roots. Signalgrass (B. decumbens) and ruzigrass (B. ruziziensis) were cultivated at increasing levels of Al in low-ionic-strength nutrient solutions for 13 d. A, Al injury at apices of adventitious roots, visualized by hematoxylin staining. B, Root fresh weight per tray containing 200 seedlings (means ± se; n = 6–7). C, Apical diameter of adventitious roots (means ± se for three images containing 150–350 apices each). D, Al content of apices from adventitious roots (means ± se of 10–17 groups of five apices each). E, Callose concentration in apices of adventitious roots expressed as Pachymann equivalents (means ± se of 11 or 12 groups of five apices each). Asterisks denote statistically significant interspecific differences (P < 0.05).