| Second-cycle lines were selected based on three maize hybrids: 'Xianyu 335', 'Dongdan 1331', and 'Dika 516'. In the winter of 2021, 108 hybrid combinations were prepared using the Griffing method (excluding parents, with only one set of F1 hybrids).From 2022 to 2023, these combinations were comprehensively evaluated for yield, lodging resistance, disease resistance, and yield stability across multiple locations and years.The results showed that the combination KPK124 (from the 'Dika 516' second-cycle line) × KPX49 (from the 'Xianyu 335' second-cycle line) exhibited the highest yield, reaching 886.5 kg/667m2 in 2022 and 780.78 kg/667m2 in 2023.This combination also demonstrated the best lodging resistance, high resistance to northern leaf blight, stalk rot, and ear rot, as well as moderate resistance to rust. These findings indicate that breeding second-cycle lines from maize hybrids with complementary key traits and selecting superior hybrid combinations can effectively develop high-performing maize hybrids. |
