Figure 1.

Effect of Al (50 μm) on the segmental elongation rate (sets A–A", B–B", C, and D) of squash roots. Sets A, A′, and A" were for control roots at 0, 3, and 6 h, respectively, marked with India ink at 2-mm intervals at 0 h. Sets B, B′, and B" represent roots treated with 50 μm Al for the same time points. Arrows denote the 2- and 4-mm positions after 3 h (A′ and B′) and subsequent alteration to their position after 6 h (A" and B"). Bars in A" and B" denote a distance of from the root tip 10 mm after 6 h. C, Elongation rate of 2-mm root regions in control and Al treatments after 3 and 6 h. D, Increment in total elongation of the apex (10 mm) during 0 to 3 and 3 to 6 h. Values in C and D are mean ± se of six replicates and representative of three independent experiments.