Wheat has always been a major dietary source of calories and protein for humans and the breeding of better bread and pasta wheat varieties is considered key for sustaining global food security. The modern-day cultivated wheat species harbor polyploid genomes, meaning that each plant has multiple functional copies of each gene. Therefore, genetic variation (such as mutations) in one gene copy are frequently masked, or hidden, by functional copies within the other genomes.

UK and US scientists have generated a new groundbreaking resource of ten million mutations in bread and pasta wheat varieties. It means that researchers and breeders from all over the world can search the public wheat database online to identify changes in their genes of interest and request seeds to improve the nutrition and production of wheat worldwide. There are close to 3,000 individual seed stocks already distributed.

Scientists expect the database will help speed up the development of the wheat crop with highly sought-after traits such as higher yields and disease resistance. They have catalogued ten million mutations by sequencing 400 billion bases of DNA from 2,735 mutant wheat lines. These hidden mutations are likely to disrupt more than 90 percent of the pasta and bread wheat genes.

The first results are starting to show, according to the John Innes Center, one of the institutes involved in the research alongside Earlham Institute, Rothamsted Research in the UK and the University of California.

Improved nutritional wheat varieties with larger grains and more dietary value have been developed using these mutations. The collection is being used to characterize gene function that control wheat flowering and adaptation to new and changing environments.

“Breeding better wheat is an ongoing major challenge that we need to meet to keep agriculture sustainable and produce varieties that are well adapted to changes in global climate.

Within the polyploid wheat genomes, there is a highly-significant amount of genetic variation that researchers can unearth that is commonly hidden - masked by multiple copies of each gene in the different wheat genomes,” says first author Dr Ksenia Krasileva, Group Leader at EI and The Sainsbury Laboratory.

“We need to identify and combine variation from different wheat genes in order to reveal the crop’s most beneficial changes.”
 
“Our study produced a well-catalogued collection of over 10 million changes in wheat genes that breeders and researchers can use today to improve wheat. Essentially, this work will help us to better understand the functions of wheat mutations that have taken place in our wheat varieties, which should hopefully aid worldwide production of wheat.”

The scientific paper “Uncovering hidden variation in polyploid wheat” will be published in PNAS.

Dr. Andy Phillips, Principal Investigator in the Dept. of Plant Biology and Crop Science at Rothamsted Research, adds: “Since before the Green Revolution, mutation breeding has been very valuable in less complex crops such as rice, which as a diploid does not have additional copies of most genes. Our work provides a valuable non-GM resource that will allow scientists and breeders to identify and combine mutations in the multiple copies of wheat target genes, allowing the effects on the plant to be observed and exploited to accelerate crop improvement.”

by Gaynor Selb