Examining 300 years of wheat collections to make crucial crop more robust for future food

17 Oct 2022 --- London’s Natural History Museum is being enlisted to help unlock the genetic secrets of wheat to help support a project focused on future food and how the genome of wheat has changed over time. This involves investigating ancient specimens of wheat which could be restored into sustainable varieties that are more resilient to climate change.

Entitled “Wheat Through the Ages,” the initiative aims to use historical collections to identify genes that could help protect vital crops like wheat from climate change.

 As one of the world’s oldest and most important crops, contributing a fifth of the total calories consumed by humans each year, wheat needs to be future-proofed as the world faces the rapid onset of climate change. 

The Food and Agriculture Organization estimates that by 2050 we will need to produce 60% more food to feed a world population of 9.3 billion - and this involves taking a different approach to farming and global food systems. 

If agricultural practices remain the same, crop yields will reduce, and there will be a heavy toll on natural resources. 

Some of the specimens in the collection date back 300 years. (Credit: The Trustees of the Natural History Museum, London)Higher yields & climate impacts
Wheat has been bred to have higher yields and relies on artificial fertilizers and pesticides. 

It has also been grown in a narrow range of conditions in temperate Europe and North America, meaning that these wheat varieties are now adapted to these environments.

“Over time, we got better at cultivating crops because we changed the way we did things, but selective breeding has resulted in the loss of genetic diversity,” explains Dr. Matt Clark, research leader at the museum. He is looking into the genetics and resilience of different wheat strains.

“The wheat crops grown now are genetically similar to each other, and this reduces their ability to adapt and decreases their resilience to new diseases,” he stresses.

Some of the specimens in the museum’s collection date back 300 years.

This is significant as scientists warn about massive global environmental change, including increased land and ocean temperatures, more frequent heatwaves, and increased frequency and intensity of extreme weather events.

It is now more vital than ever that we develop strains of wheat that are less reliant on these fertilizers and pesticides and that can be grown in harsher climates. 

The answers to some of these problems may be found in the DNA sequences of wheat.

Wheat collection
The museum’s herbarium contains around 8,000 specimens belonging to the Triticeaea group of plants, which includes wheat, barley, rye and wild crop relatives. This collection stretches back to the 1700s, covering a period that predates modern agricultural practices that changed the genome of the wheat we consume.As one of the world’s oldest and most important crops, wheat needs to be future-proofed as the world faces the rapid onset of climate change. 

These ancient specimens may contain some genes which could be reintroduced to the varieties of wheat we eat to develop more sustainable strains. Plants that are close relatives to wheat may also be able to be crossbred to introduce new genes.

Scientists will sequence the entire genomes of a selection of wheat specimens to discover how the genome has changed through time. 

But deciding which of the thousands of specimens in the collections to sequence is something of a challenge. This is where digitization comes in.

Grains of truth
Digitizing the museum’s collections allow for specimens to become freely searchable by anyone.

“These herbarium collections are a treasure trove, filled with information about what we grew, where and how we grew it, and so how we could grow it again,’ adds Dr. Clark. 

“While modern varieties give amazing yields, many of these old varieties have genes that we need around the world again to grow in marginal lands, to deal with hotter, drier climates, and to grow well with less energy-intensive fertilizer.” 

Digitization means the scientists will have a searchable dataset of Tritichae specimens where they can see the collection’s spread through time and space. This can then be cross-referenced with historical information so that the researchers can choose specimens for sequencing from before and after the introduction of agricultural practices (like the use of artificial fertilizer) to see how the wheat genome has changed over time.

Digitization also allows researchers to highlight specimens that look like they might be interesting to use for further research. For example, specimens with visible signs of disease, such as lesions, may contain genes for disease resistance, and specimens with lots of soil still present in the roots could potentially be used for soil analysis.

Edited by Gaynor Selby