Figure 7.

Effect of GA₃ application on starch level (A), and starch granules accumulation (B) in sweetpotato “Georgia Jet” roots. Starch level was quantified in roots collected at two and five weeks (2W and 5W, respectively) after planting. At 5W, both adventitious roots (AR) that did not develop into storage-root (SR), and SR were analyzed. Bars in (A) represent mean of three independent biological replicates (each representing roots pooled from four plants) ± SE. Significance analysis was performed by using student’s t-test (P ≤ 0.05), where unlike letters represent significant differences between treatments within a group. Cross sections of SR collected at 5W of development, representing six independent biological replicates (plants), are given in (B) as viewed under a confocal microscope focusing on starch granules. Scale bar = 50 µm and 10 µm (in inset). Control (treated with water); GA₃, application of 50 ppm gibberellic acid 3 for two weeks; PB, application of 5 ppm paclobutrazol for two weeks.