Fig. 2From: Implication of quantifying nitrate utilization and CO2 assimilation of Brassica napus plantlets in vitro under variable ammonium/nitrate ratiosThe δ13C values of Brassica napus plantlets in vitro cultured under nitrate treatment. Note: Each nitrate treatment contained 20 mM ammonium. The mean ± SE (n = 3) followed by different letters in the bar graph differ significantly (Tukey’s test, p < 0.05)Back to article page