2.2.3. Determination of Endogenous Hormone Content

High-performance liquid chromatography—mass spectrometry (HPLC—MS) (Aibo CAISI Analytical Instrument Trading Co., Ltd., Shanghai, China) was employed for the determination [23] (The column, Waters ACQUITY HPLC HSS T3 C18 (100 mm × 2.1 mm i.d., 1.8 μm). Methanol and 0.1 mol/L−<sup>1</sup> acetic acid were deemed as the mobile phase for gradient elution, and the contents of IAA, abscisic acid (ABA), zeatin riboside (ZR), gibberellin (GA3), jasmonic acid (JA), strigolactone (SL), and IBA were determined at 254 nm for the vegetable mulberry cuttings control group (CK1), the vegetable mulberry cuttings treatment groups with 200 mg·L−<sup>1</sup> ABT-1 (A1), 500 mg·L−<sup>1</sup> ABT-1 (A2) and 1000 mg·L−<sup>1</sup> ABT-1 (A3), and the fruit mulberry cuttings control group (CK2), the fruit mulberry cuttings treatment groups with 200 mg·L−<sup>1</sup> ABT-1 (B1), 500 mg·L−<sup>1</sup> ABT-1 (B2) and 1000 mg·L−<sup>1</sup> ABT-1 (B3) on days 1, 28, and 48, respectively. The study was repeated three times.
