Fig. 1.

Aluminum tolerance of six rice cultivars under different light conditions. Five-day-old rice seedlings were treated for 24 h with 10 µM AlCl₃ in the presence of 0.2 mM CaCl₂ (pH 4.9), and Al tolerance was calculated as the ratio of net elongation of the longest root in the Al treatment to that in the control (0.2 mM CaCl₂ without Al). Twelve seedlings with similar root length (ca 4 cm) were used for one set in Al tolerance analysis. Analysis was carried out independently for five sets for L, four sets for D, and two sets for DMG. L, light; D, dark; DMG, dark in the presence of 1 mM mevalonate and 1 mM glucose. Rice cultivars: Ka, Kasalath; Ko, Koshihikari; Hi, Hidekomochi; No, Norin-21; R₂₀, Rikuu-20; R₁₃₂, Rikuu-132. Values are means of independent replicates±standard error. Different letters above bars indicate significant differences (P<0.05; Fisher’s LSD).