Research on Regional Adaptability and Stability of Maize Varieties in Mid-to-High Altitude Areas of Yunnan Province Based on GGE Biplot Analysis

Identifying superior genotypes in multi-environment trials is crucial for accelerating cultivar improvement and breeding innovation. This study evaluated the yield potential of 29 maize hybrids (including the control) across 10 trial locations in mid-to-high altitude regions of Yunnan Province from two growing seasons (2023-2024), aiming to recommend high-yielding, stable, and widely adapted maize varieties. Analysis of variance indicated that genotype, environment, and their interaction all had highly significant effects (p < 0.001) on maize yield, with environmental factors accounting for the primary source of variation. Yield mean analysis identified the top-performing hybrids annually: in 2023, these were G28, G13, G22, G3, G10, G9, and G27; in 2024, they included G5, G13, G4, G2 G27, G22 and G26. The GGE biplot analysis identified E2 (Binchuan), E5 (Lijiang), E7 (Shilin), and E8 (Xuanwei) as optimal testing environments. Among elite genotypes, G22 (LS-2305), G9 (LS-2303), and G13 (YR-399) exhibited consistent high yields and stability across years, with G13 (YR-399) emerging as the most outstanding. Therefore, these findings confirm that the GGE biplot method is effective for screening high-yielding, stable varieties and identifying representative test environments, thereby providing a scientific foundation for maize breeding work in the region.