Abstract: [Objective] To investigate the effects of ABT rooting powder concentration, soaking duration, and cultivation time on the rooting performance of hydroponic cuttings of Medicago sativa using hydroponic cutting techniques. [Methods] The experiment set three rooting powder concentrations （200, 500, 800 mg/L, labeled A1, A2, A3） and three soaking durations （10, 30, 60 s, labeled B1, B2, B3), forming nine treatment combinations through full factorial design （denoted as A1B1, A1B2, A1B3, A2B1, A2B2, A2B3, A3B1, A3B2, A3B3）, with tap water treatment as the control （CK）, totaling 10 treatment groups. Rooting rate, average number of adventitious roots, and longest root length were measured on days 10, 17, and 24, and a comprehensive rooting performance score was calculated using principal component analysis （PCA）-based scoring. [Results] The results showed that on day 10, the A2B1 treatment had the highest rooting rate （23.33%）, A2B2 had the highest average number of adventitious roots （4.72 roots per cutting）, A2B2 exhibited the longest root length （45.88 mm）, and A1B2 achieved the highest comprehensive rooting performance score （3.23）. On day 17, A2B1 had the highest rooting rate （71.11%）, A2B2 had the highest average number of adventitious roots （4.61 roots per cutting）, A2B1 showed the longest root length （164.04 mm）, and A2B1 had the highest comprehensive rooting performance score （2.47）. On day 24, A2B1 had the highest rooting rate （74.45%）, A2B2 had the highest average number of adventitious roots （5.56 roots per cutting）, A3B1 exhibited the longest root length （237.97 mm）, and A2B1 achieved the highest comprehensive rooting performance score （2.84）. [Conclusion] The rooting rate, root length, and average number of adventitious roots of M. sativa cuttings were closely related to rooting powder concentration, soaking duration, and cultivation time, showing significant differences in rooting performance among treatment combinations. The best comprehensive rooting performance at 10 days was observed with 200 mg/L ABT rooting powder soaked for 10 s, while at 17 and 24 days, the optimal combination was 500 mg/L ABT rooting powder soaked for 10 s.

Key words: hydroponic cutting, rooting rate, number of roots, longest root length, comprehensive rooting performance, principal component analysis