3.5.6. Changes in Endogenous SL

According to Figure 4F, the SL content presented a sustained decreasing trend. By viewing the overall rooting period, the largest change appeared in the control group, while the change in the optimal treatment 500 mg·L−<sup>1</sup> ABT-1 was relatively small, suggesting that the effect of endogenous hormones on cuttings is the result of the combined action of multiple hormones.

#### 3.5.7. Changes in Endogenous IBA

As indicated in Figure 4G, endogenous IBA content exhibited a similar change with the changes of GA3 and SL. The highest level of endogenous IBA occurred in the initiation stage, followed by a gradual decrease till the emergence and elongation of adventitious roots. The lowest level of endogenous IBA was observed in the control group (1.4 ng·g<sup>−</sup>1), while the content of ABT-1—500 mg·L−<sup>1</sup> was 3.6 times higher than that of the control group, suggesting that a higher IBA content can accelerate the growth of fruit mulberry cuttings.
