Harnessing biotechnology to promote the utilization of crop heterosis

Abstract

Heterosis (hybrid vigor) serves as a foundational theory and technical basis for modern crop improvement, driving significant advancements in agricultural productivity. With the rapid development of biotechnology, its integration with breeding technologies has profoundly enriched the methodologies and applications of heterosis research. Based on the reports at the 1st Crop Heterosis and Bio-Breeding Conference of China, this review provides a comprehensive review of recent advances in crop heterosis and biological breeding, revisiting the historical development of heterosis mechanisms and its utilization technologies. Notably, breakthroughs in maize and rice hybrids, such as the commercialization of “You Shu 1” in potatoes and the molecular design of male-sterile lines using ZmMs7 in maize, exemplify the transformative power of genomic tools in hybrid breeding systems. Key discussions include research on reproductive development and male sterility mechanisms, and their roles in heterosis exploitation. For instance, the discovery of environment-sensitive nuclear male sterility genes (e.g., OsTMS15 in rice) and the development of multi-control sterility (MCS) systems in maize have revolutionized hybrid seed production by eliminating manual emasculation and improving field efficiency by up to 30%. Besides, the review highlights key genes that determine traits critical to crop yield, production efficiency, and stress-regulated growth and development. Recent studies identified AT1, a conserved Gγ subunit gene in cereals, as a negative regulator of saline-alkaline tolerance; its knockout via CRISPR-Cas9 enhanced crop yields by 20%–30% in salt-affected soils, demonstrating the practical impact of gene editing in stress resilience breeding. The review further examines the application of genomic analysis in biological breeding, as well as the transformative impact of integrated and scalable breeding technologies such as gene editing and synthetic biology on breeding efficiency. For example, the integration of genome-wide association studies (GWAS) and machine learning has enabled the identification of heterosis-related loci in hybrid rice, such as qHMS7 and qHMS1, which regulate gamete viability and hybrid sterility. Moreover, the adoption of artificial intelligence(AI)-driven phenotyping platforms, achieving 95% accuracy in yield prediction, has accelerated the selection of drought-tolerant maize varieties like CIMBL55, which harbors 65 stress-adaptive alleles. Additionally, it outlines pathways for developing new quality-based productivity in the crop seed industry through improved seed quality, enhanced regional specificity in breeding, and elevated breeding entity capacities. Case studies from Xinjiang’s seed industry illustrate region-specific breeding strategies: XL1822 for grain maize, WT507U8 for silage, and Xianyu 5 for fresh consumption, all tailored to local agroecological conditions. Innovations in seed vigor testing, such as GC-IMS-based predictive models for natural aging, have optimized seed storage and planting schedules, boosting germination rates by 15% in high-value hybrids. Finally, the review identifies future research directions, including elucidating the molecular mechanisms underlying heterosis, unlocking the application potential of gene editing technologies, optimizing biological breeding paradigms through AI and big data, and addressing the impact of climate change on breeding. Emerging tools like single-cell multiomics and spatial transcriptomics are poised to unravel spatiotemporal gene expression dynamics in hybrids, while synthetic biology platforms, such as carotenoid metabolic modules engineered in cotton, offer novel pathways for trait stacking. Policy frameworks promoting public-private partnerships are critical for scaling these technologies and ensuring equitable access. These insights aim to provide theoretical and technological references for ensuring food security and promoting sustainable agricultural development. By bridging cutting-edge science with scalable solutions, this synthesis charts a roadmap for next-generation breeding systems capable of meeting the dual challenges of population growth and climate volatility.