Deciphering the role of genotype-by-environment interaction in summer maize hybrids based on multiple traits using envirotyping techniques and genotype by yield × trait approaches

Context

The use of high-yielding, stable, and widely adaptable summer maize hybrids is essential for the sustainable cultivation of maize globally. However, contemporary breeding programs face challenges in identifying genotypes that exhibit consistent performance while maintaining desired agronomic characteristics across diverse environments. Dynamic shifts in global meteorological and edaphic conditions have impacted the evaluation of summer maize performance in China's multi-environment trials (METs). Multi-perspective analysis of genotype-by-environment interactions (GEI) is then essential for characterizing maize yield stability and trait expression across agroecological zones.

Objective

This study aims to comprehensively evaluate the performance and stability of maize genotypes in the Huang-Huai-Hai region by integrating environmental techniques (ETs) with multi-trait selection methods.

Methods

Twenty-eight maize hybrids and a check hybrid (ZD958) were evaluated across 29 locations in the Huang-Huai-Hai region of China during the 2019–2021 cropping seasons, using a randomized complete block design (RCBD) with three replications.

Results

Based on 30 years (1993–2023) of environmental data, which included 19 meteorological and 6 soil physicochemical factors, the ETs classified the 29 locations across eight provinces into six distinct mega-environments (MEs). The additive main effects and multiplicative interaction (AMMI) model analysis revealed that genotype (G), environment (E), and their interaction (G×E) significantly influenced (p < 0.05) for all agronomic parameters from 2019 to 2021. The combined performance of grain yield and other agronomic traits—such as growth period, plant height, ear height, lodging rate, barren stalk rate, grain moisture content at harvest, ear row number, bare tip length, and 100-grain weight—across different MEs was assessed using the genotype by yield × trait (GYT) biplot approach. The integration of GYT biplots with ETs effectively identified dominant hybrids across different MEs. Among the evaluated hybrids from 2019 to 2021, HY1604 exhibited both high yield and stability in MEs 1–4, categorizing it as a high-yielding, stable hybrid. HY573 and SD610 demonstrated relatively balanced performance in yield-trait combinations in MEs 5 and 6, respectively. The control hybrid, ZD958, showed strong stability but average yield performance over the three-year MET period.

Implications

The use of environmental characterization techniques to delineate MEs, combined with the GYT biplot approach to evaluate yield, adaptability, and stability, facilitated precise variety placement, and provided a robust theoretical framework for the comprehensive evaluation of multiple traits in summer maize hybrids in the Huang-Huai-Hai region of China.