Evolutionary Insights into Wheat Quality and Breeding-by-Design Strategies

Researchers from the Chinese Academy of Sciences and the Shandong Academy of Agricultural Sciences have assembled a high-quality reference genome for Jimai 44, a widely cultivated strong-gluten wheat variety in China. The findings, published in the journal Nature Plants, provide a detailed map of the evolutionary history of wheat quality and offer new frameworks for precision breeding.

The research was led by LU Fei from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences, in collaboration with a team led by CAO Xinyou from the Shandong Academy of Agricultural Sciences. The study focuses on the genetic determinants of wheat processing properties, specifically the gluten proteins stored in wheat grains that dictate dough elasticity and extensibility.

For decades, agricultural breeders have recognized the importance of several high-molecular-weight glutenin subunits in achieving strong-gluten quality. However, identifying the specific genetic variants responsible for these traits has been historically difficult because the genes encoding gluten proteins are structurally complex, highly repetitive, and clustered within the wheat genome.

These genomic complexities have limited the ability of scientists to fully resolve important genomic regions, which in turn hindered the discovery of key quality-related variants and the understanding of the molecular basis of superior wheat quality.

To overcome these obstacles, the research team used the Jimai 44 variety to generate a reference genome that fully resolves the fine-scale structure of gluten protein loci. This genomic data was combined with a whole-genome variation map derived from 485 wheat and related accessions.

By analyzing this data, the researchers reconstructed the adaptive evolutionary history of wheat processing quality. The study tracked these traits through four primary stages: domestication, polyploidization, Eurasian dissemination, and modern Chinese breeding.

The results reveal how strong-gluten wheat quality traits evolved during the process of breeding and adaptation, providing a new perspective on how wheat was shaped into a crop suitable for diverse food-processing purposes.

The assembly of the Jimai 44 genome is intended to facilitate the development of more efficient and precise breeding strategies. The researchers propose a “breeding-by-design” approach, which leverages the resolved genomic structure to target specific quality traits more accurately than traditional breeding methods.

The publication in Nature Plants included both the primary study and a corresponding Research Briefing to detail the implications of the genomic assembly for future wheat production and quality control.