Evaluation and Selection of Spring Wheat Cultivars for Adaptation to the Wheat–Soybean Double-Cropping System

The wheat–soybean double-cropping system enables the continuous production of preceding and succeeding crops within the same growing season, providing an important approach for improving arable land-use efficiency, increasing output per unit area, and optimizing cropping structure. In Liaoning Province, where thermal resources and the frost-free period are relatively limited, this system places high requirements on the growth duration, yield stability, and succession compatibility of the preceding wheat crop with the succeeding soybean crop. To identify spring wheat cultivars suitable for this system, field trials were conducted from 2021 to 2023, using three representative ecological regions of Liaoning Province. Ten widely grown spring wheat cultivars were evaluated for major agronomic traits, grain quality, and disease resistance, and their stability and system adaptability were analyzed using a mixed linear model, GGE biplot analysis, and TOPSIS. The results showed clear differences among cultivars in growth duration, wheat yield, and succeeding soybean yield. Liaochun 33 and Liaochun 18 had relatively short growth durations of 78–84 days and 79–83 days, respectively, and showed favorable performance in wheat yield, succeeding soybean yield, and stability. Combined with grain quality, disease resistance, and TOPSIS-based comprehensive evaluation, Liaochun 33 showed the best overall performance, while Liaochun 18 also exhibited strong system adaptability. Overall, cultivar selection for the wheat–soybean double-cropping system in Liaoning Province should shift from single wheat-yield evaluation to overall system-benefit evaluation. Liaochun 33 and Liaochun 18 can be recommended as preferred spring wheat cultivars for this cropping system.