Achieving High-Density and Stress-Resilient Maize Breeding Via Germplasm Innovation.

Given the global population growth and climate change, feeding the future 10 billion people has become an urgent challenge. As a worldwide crop, maize is pivotal in meeting this demand. Increasing planting density has long been regarded as an effective approach to enhancing maize yield in most production regions. In this perspective, we propose to increase planting density by optimizing plant architecture and balancing population-level and individual-level advantage, while also improving individual productivity by optimizing yield components, ideal ear architecture, and enhancing photosynthetic efficiency. Gene pyramiding has been proposed to enhance stress resistance, together with reinforcing lodging resistance, and shifting to earlier diurnal flower opening time to escape heat stress. Additionally, improving nutrient use efficiency can reduce fertilizer dependence, while increased photothermal insensitivity can broaden ecological adaptability. To achieve these objectives, we outline a four-step modern breeding pipeline integrating variation generation, selection, fixation, and genomic selection for hybrid prediction.