3.5.9. Changes in IAA/ZR Ratio

The IAA/ZR ratio of the treatment group with 500 and 1000 mg·L−<sup>1</sup> ABT-1 and the control group showed a trend of decreasing before increasing, while that of ABT-1— 200 mg·L−<sup>1</sup> exhibited a continuous decreasing trend (Figure 4I). By combining with the analysis of rooting process and morphology, the IAA/ZR ratio of the optimal treatment group 500 mg·L−<sup>1</sup> ABT-1 reached the lowest value during the callus formation, peaked during the emergence and elongation of adventitious roots, and was significantly higher than that of other treatments. This indicates that a higher IAA/ZR ratio is conducive to the elongation of adventitious roots.
