BIOTECHNOLOGICAL ADVANCES IN CHINESE WHEAT IMPROVEMENT: GENOME EDITING, MOLECULAR BREEDING, AND CLIMATE RESILIENCE

Abstract

Hexaploid wheat (Triticum aestivum L., 2n=6x=42, AABBDD) is the basic staple food crop throughout China, accounting for more than 20% of the calorie and protein needs of the Chinese people. As climate change becomes more extreme, pathogen dynamics change, and land use is limited, the old paradigms of phenotypic and empirical breeding are no longer enough to maintain the genetic gain needed to meet national food security goals. In the last ten years, Chinese plant biotechnologists have led the way in structural and functional innovations in three closely interconnected areas: precision genome editing, multi-omics molecular design breeding, and climate-resilient trait architecture optimization. This review gives an exhaustive overview of these developments. We assess the improvement of the CRISPR/Cas9 and cytosine and adenine base editors (CBE/ABE) for targeting the highly repetitive 16-Gb wheat hexaploid genome. We trace the evolution of marker-assisted selection (MAS) to high-throughput genomic selection (HS) and genome-wide association studies (GWAS) as well as machine learning-based multi-trait pyramiding. Additionally, we explore the genetic and physiological dissection of stress-tolerance networks used by Chinese institutes to deal with extreme drought, extreme heat, salinity, and devastating biotic stresses such as Fusarium head blight (FHB), powdery mildew, and stripe rust. Finally, the current regulatory frameworks, outcomes of field trials in translation, and the strategic direction to facilitate the commercialization of edited germplasm in the Chinese context are analyzed. This review aims to summarize the quantitative milestones of the modern history of biotechnology of wheat.