The seeds of Tilia miqueliana Maxim. exhibit deep dormancy, which is categorized as combinational dormancy. This study utilized a comprehensive treatment involving magnetic fields, gibberellin (GA₃), and cold stratification to promote the release of seed physiological dormancy and enhance germination rates. After being soaked in 98% H₂SO₄ for 15 min, mature seeds of Tilia were exposed to magnetic field treatments (150 MT, 250 MT) for different durations (25 min, 45 min, 65 min, and 85 min), as well as GA₃ solution soaking (concentration: 0 μmol·L⁻¹, 1443 μmol·L⁻¹). Subsequently, cold stratification (0–5 °C) was applied to investigate the effects of these treatments on seed dormancy release and nutrient transformation. The results indicated that the comprehensive treatment involving magnetic field, GA₃ solution soaking, and cold stratification effectively released the physiological dormancy of Tilia seeds and improved germination rates. Among the treatments, M₁₅₀T₈₅G₁₄₄₃ (magnetic field intensity: 150 MT, magnetic field treatment time: 85 min, GA₃ soaking concentration: 1433 μmol·L⁻¹) exhibited the most favorable outcome. After 75 days of cold stratification following the comprehensive treatments, the germination rate of M₁₅₀T₈₅G₁₄₄₃ seeds reached 89%. Additionally, the levels of storage substances such as starches and crude fats within the seeds decreased, while the utilization of soluble sugars and soluble proteins increased. The M₁₅₀T₈₅G₁₄₄₃ treatment exhibited the highest degree of variation, leading to gradual increases in metabolic activities of the seeds and a transition from dormancy to germination.

By measuring the changes in phytohormones and related enzyme activities of Malus ‘Huabiao’ scions and different rootstocks during the healing process of grafting, this study aims to analyze the effects of different rootstocks on the physiological metabolism of the grafting healing site, thereby providing reference for the selection of M. ‘Huabiao’ grafting rootstocks. The live seedlings of 1-0 M. hupehensis, M. robusta and M. baccata were chosen as rootstocks, and M. ‘Huabiao’ scions were grafted with these seedlings in spring by pasting method. The dynamic changes in activities of indole acetic acid, zeatin riboside, methyl jasmonate content and peroxidase, polyphenol oxidase and L-phenylalanine ammonia-lyase at the healing site of grafting were measured, and the effects of different grafting combinations on the phytohormone and related enzyme activities at the grafted site were investigated. It was found that the M. ‘Huabiao’/M. hupehensis and M. ‘Huabiao’/M. robusta grafting combinations had significantly higher survival rate than M. ‘Huabiao’/M. baccata which only had a success rate of 63%. At the beginning of graft healing, the contents of three phytohormones in healing sites of all the three grafting combinations exhibited a significant decrease. However, in the mid and late stages, great differences were shown in phytohormone content. During the grafting healing process, the changes in three enzyme activities in healing sites of the three grafting combinations showed some regularities. In conclusion, M. hupehensis and M. robusta have strong grafting compatibility with M. ‘Huabiao’; thus, they are suitable to be selected as rootstocks for grafting and propagation of M. ‘Huabiao’. In addition, the changes in phytohormone content and enzyme activity in different grafting combinations reflect the strong affinity relationship between rootstock and scion grafting.