| To screen suitable apple dwarf rootstock-scion combinations using T337 as the rootstock for cultivation in the Loess Plateau region, and to provide a scientific basis for rootstock selection in dwarf and high-density apple orchards, this study evaluated five graft combinations: ''Qincui''/T337 (QC), ''Hongsinike''/T337 (HS), ''Venus Gold''/T337 (WN), ''Ruixue''/T337 (RX), and ''Yanfu 8''/T337 (YF). Using five-year-old trees as experimental materials, we continuously measured tree growth indicators and photosynthetic parameters of each combination during 2023–2024. Additionally, cold-resistance-related physiological indices were assessed under a gradient of low-temperature treatments (4 °C, ?10 °C, ?20 °C, ?25 °C, and ?30 °C). A membership function method was employed for comprehensive evaluation. The results showed significant differences among the five combinations in growth characteristics, photosynthetic performance, and cold tolerance. The comprehensive evaluation based on membership function values ranked the combinations as follows: ''Hongsinike''/T337 achieved the highest score (0.60), followed by ''Yanfu 8''/T337 (0.59), ''Qincui''/T337 (0.50) ranked third, while ''Venus Gold''/T337 (0.43) and ''Ruixue''/T337 (0.41) ranked fourth and fifth, respectively. ''Hongsinike''/T337 exhibited well-coordinated performance in growth vigor, photosynthetic efficiency, and cold-resistance-related physiological traits, demonstrating superior overall performance. Therefore, it can be recommended as the preferred dwarf rootstock-scion combination for apple high-density planting in the Loess Plateau region. |