Fig. 1.

Effect of Al on root elongation of two maize cultivars ‘B73’ (Al sensitive) and ‘Nongda3138’ (Al resistant). Three-day-old seedlings were subjected to 0·5 mm CaCl₂ solution (pH 4·5) with 0 or 50 µm Al. Root lengths were measured before or after Al treatment with a ruler. Relative root elongation was defined as root elongation with Al/root elongation without Al (× 100). Values are means ± s.d. (n = 10).