KANSAS CITY, MISSOURI, US — Scientists from around the world contributed to a new study thought to allow wheat breeders to improve global crop yield, quality and resistance to pests to better meet global demand, which is expected to more than double by 2050.
The 10+ Genome Project sequenced and analyzed the genomes of 15 wheat varieties in what has been called the most comprehensive atlas of wheat genome sequences ever documented. It is hoped that the atlas will serve as a roadmap to help wheat breeders quickly identify influential genes that drive yield and quality characteristics and resist pests and disease.
The project was shepherded by Curtis Pozniak, a professor and director of the University of Saskatchewan’s Crop Development Centre. He is also a wheat breeder who has overseen the release of 15 new wheat varieties over 17 years.
“This resource enables us to more precisely control breeding to increase the rate of wheat improvement for the benefit of farmers and consumers, and meet future food demands,” Pozniak told the university’s news division.
Wheat’s role in global food security cannot be underestimated as the world looks ahead to increased global demand. As one of the world’s most cultivated cereal crops, wheat provides about 20% of human caloric intake across the globe. Food scientists have estimated world wheat production needs to increase 50% by 2050 to meet demand.
“It’s like finding the missing pieces for your favorite puzzle that you have been working on for decades,” Pozniak said. “By having many complete gene assemblies available, we can now help solve the huge puzzle that is the massive wheat pan-genome and usher in a new era for wheat discovery and breeding.”
Several agricultural crops already have been improved through genomic research. But the size and complexity of the wheat genome and the lack of genome-assembly data for multiple wheat lines made a thorough mapping of wheat far more challenging.
The study, “Multiple wheat genomes reveal global variation in modern breeding,” explored the diversity among wheat lines from global breeding programs. The 15 lines were pre-selected, but field experiments were randomized without predetermined sample sizes, according to the study published Nov. 25 in Nature.
From the study’s summary: “Comparative analysis revealed extensive structural rearrangements, introgressions from wild relatives and differences in gene content resulting from complex breeding histories aimed at improving adaptation to diverse environments, grain yield and quality, and resistance to stresses.”
The 10+ Genome Project is planned as the first step in a larger effort to generate thousands more wheat genome sequences, including those of wheat’s wild relatives. The project allowed researchers to track DNA signatures of genetic material in modern cultivars incorporated over several centuries from wheat’s undomesticated relatives.
Collaborators included scientists from Kansas State University, Manhattan, Kansas, US, who helped isolate a disease-resistance gene, Pozniak said.
“These wheat relatives have been used by breeders to improve disease resistance and stress resistance of wheat,” he said. “One of these relatives contributed a DNA segment to modern wheat that contains disease-resistant genes and provides protection against a number of fungal diseases. Our collaborators from Kansas State University and the International Maize and Wheat Improvement Center in Mexico showed that this segment can improve yields by as much as 1%. Since breeding is a continual improvement process, we can continue to cross plants to select for this valuable trait.”
Other scientists used the genome sequences to isolate an insect-resistant gene that lets a plant withstand the orange wheat blossom midge, a pest that can cause upwards of $60 million in annual losses to Western Canadian producers.
“Understanding a causal gene like this is a game-changer for breeding because you can select for pest resistance more efficiently by using a simple DNA test than by manual field testing,” Pozniak said.
The University of Saskatchewan team was part of another international collective that in 2018 decoded the genome for the bread wheat variety Chinese Spring, a study that was published in Science.
“Now we have increased the number of wheat genome sequences more than 10-fold, enabling us to identify genetic differences between wheat lines that are important for breeding,” he said. “We can now compare and contrast the full complement of the genetic differences that make each variety unique.”
The speed with which the 10+ project followed the Chinese Spring mapping impressed plant scientists.
“Given the significant impact of the Chinese Spring reference genome on research and application, it is a major achievement that just two years later we are providing additional sequence resources that are relevant to wheat improvement programs in many different parts of the world,” said Nils Stein of the Leibniz Institute of Plant Genetics and Crop Plant Research who served as a project co-leader from Germany.
The 10+ Genome Project combined the research of more than 95 scientists from universities and institutes in Australia, Canada, Germany, Israel, Japan, Mexico, Saudi Arabia, Switzerland, the United Kingdom, and the United States.