Figure 2.

Effect of γ-aminobutyric acid (GABA) as a foliar application at 1 and 2mM on leaf pigments concentration of tomato plants cv “Super marmende” growing under normal (25°C/20°C day/night ) and chilling conditions (5 days/4ºC for 6 h/day) followed by 2 days recovery. (A), chlorophyll a; (B), chlorophyll b; (C), total chlorophyll; (D), chlorophyll a/b ratio; (E), carotenoids, and (F), anthocyanin. Data followed by the same letters ± SE are not significant according to Duncan multiple rang test at P≤0.05. The white columns refer to the control conditions and the black columns refer to the chilling stress.