FIGURE 1.

Number of xylem fiber-like cells counted in vascular cylinder radius (A), xylem cylinder thickness (B), length of xylem fibers (C) and number of vessel elements counted in vascular cylinder radius (D) of tobacco plants grown in high irradiance (full sunlight) and shade (8.5% of sunlight) environments and submitted to distinct gibberellin regimes. Cont (Control); GA10 (10 μM of gibberellic acid – GA₃); GA100 (100 μM GA₃) PAC (50 mg L⁻¹ of paclobutrazol), and GA10P (combined GA₃ 10 μM + PAC); GA100P (combined GA₃ 100 μM + PAC). Different capital (full sunlight) or lowercase (shade) letters over bars indicate statistical difference between treatments on similar light regimes by Duncan’s test (P < 0.05). Asterisks indicate statistical difference between lights on similar GA regimes by Student t test (P < 0.05). (n = 6 ± SE).