Maize is central to global food, feed and industrial systems. It is also exposed to mounting pressure from climate change, resource constraints and environmental pollution linked to intensive fertilizer use. Breeding higher-yielding maize is therefore no longer sufficient on its own. The crop must also become more efficient in its use of nutrients and more resilient to environmental stress.
In a Short Communication published by Science Bulletin , researchers led by Xiangyuan Wan and Xun Wei at the University of Science and Technology Beijing, with collaborators from China Agricultural University, Zhejiang University, Wageningen University & Research and the International Maize and Wheat Improvement Center, provide a global assessment of how G&E maize varieties could contribute to SDGs.
The researchers classified 48 G&E maize traits into four groups: biotic stress resistance, abiotic stress tolerance, ideal plant morphology and architecture, and efficient nutrient use. These traits include insect resistance, drought and heat tolerance, nitrogen use efficiency and compact plant architecture suitable for high-density planting.
To locate genetic entry points for multi-trait improvement, the researchers integrated 27,516 QTNs and 3,272 QTLs into 691 QTN clusters and 386 QTL clusters. Across the four trait categories, they detected 293 common genomic regions. Among 524 previously reported genes associated with these traits, 227 were located within 98 common clusters. These 98 regions can be interpreted as priority genomic hotspots, giving breeders and geneticists a tractable set of regions for fine mapping, gene editing, multi-omics profiling and molecular design breeding.
The authors also compiled 539 maize varieties worldwide that carry one or more G&E traits. Most were developed through hybrid breeding or genetic modification. The current portfolio is dominated by technically accessible traits such as insect resistance and herbicide tolerance, while more complex traits such as nitrogen use efficiency, cold tolerance and salt tolerance remain underrepresented.
A meta-analysis of 1709 field observations from 96 studies showed that G&E maize varieties increased yield by 10.1% overall, and 12.7% after trim-and-fill adjustment. Yield effects differed by continent, breeding technology and trait type. Varieties combining insect resistance and drought tolerance showed particularly large gains in the compiled studies. The nitrogen results showed both promise and a warning. G&E varieties improved nitrogen utilization efficiency, the conversion of absorbed nitrogen into grain yield, by 16.7%. However, nitrogen uptake efficiency declined by 13% in the available dataset. It nevertheless highlights a key breeding challenge: improving yield and aboveground nitrogen use without weakening root-based nitrogen acquisition.
To estimate future global potential, the team applied random forest models to 561,359 gridded soil and climate observations. Under a full-adoption scenario for ideal G&E maize varieties, the models projected an 18.1% increase in global maize yield, equal to 145.78 Tg additional grain per year, and a 26.6% reduction in reactive nitrogen losses, equal to 1.49 Tg less reactive nitrogen per year. These projections represent upper-bound biological potential. When the modelled gains are scaled to current adoption levels in low-efficiency target regions, the near-term benchmark is about a 9% yield gain and a 13% reduction in reactive nitrogen losses.
The analysis revealed a three-stage translation gap. First, research has not yet produced commercial varieties that reliably combine three or more G&E traits. Second, many reported varieties have not reached commercial production, especially in regions where expected benefits would be high. Third, deployed varieties only achieve their full value when paired with suitable fertilization, planting density, pest control and market conditions. The study concludes that realizing the potential of G&E maize will require coordinated action across genetics, breeding, regulation, seed systems and crop management. AI-based genomic selection, gene editing, synthetic biology and multi-environment field trials could help assemble beneficial allele combinations. Policy and market interventions will also be needed so that improved varieties reach farmers in high-need regions.
Science Bulletin
Meta-analysis
Green and efficient maize varieties synergize global yield and nitrogen sustainability
30-Aug-2026