Fig. 3.
Effects of atrazine on the photosynthetic apparatus of plantlets of the different accessions grown for 2 weeks in the absence of atrazine and transferred for 5 d to fresh medium in the absence or presence of 10 µm atrazine. Fv/Fm was determined on whole plantlets (A); chlorophyll (B) and carotenoid (C) levels were measured on shoots. Results (mean ± s.e.m.) are expressed as the percentage relative to the values obtained on plantlets of the same genotype transferred for 5 d to control medium in the absence of atrazine. Statistical comparison between means was carried out using one-way ANOVA followed by Duncan's test. Statistical significance of differences (P ≤ 0·05) between accessions is indicated by different letters above bars.