Figure 7.

Blue light fully inhibits the emergence and upward growth of ARs. A, Percentage of penetrated roots at the third node of cv PG56 stems exposed to darkness (0), blue light (B), or white light (WL) for 3 d. B, Average root growth angles in increasing blue light fluence rates and in white light in the presence of 150 μm ethephon (WL+E). Values are means ± se from three independent experiments, with 16 to 20 stems analyzed per treatment. Different letters indicate statistically significant differences (P < 0.05, ANOVA with Tukey’s test).