A picture of ripe, golden wheat in a field.

By delving into historic specimens of food crops, scientists hope to find genes that might help the future ©Vintagepix/Shutterstock

Read later

Beta

During Beta testing articles may only be saved for seven days.

Unlocking wheat's genetic secrets to feed the world

A new project called Wheat Through the Ages aims to use the Museum's historic collections to investigate how the genome of wheat has changed through time, and hopefully identify genes that could help protect crops from climate change. 

Wheat is a grain used in some of our favourite foods from bread and pasta, to breakfast cereals and pastries.

It is one of the world's oldest and most important crops, contributing a fifth of the total calories consumed by humans each year. The Food and Agriculture Organisation estimate that by 2050 we will need to produce 60% more food to feed a world populations of 9.3 billion.

Doing this with a farming-as-usual approach would take too heavy a toll on our natural resources.

Wheat has been bred to have higher yields and to be reliant on artificial fertilisers and pesticides. It has also been grown in a narrow range of conditions in temperate Europe and North America, meaning that these varieties of wheat are now adapted to these environments.

Dr Matt Clark is a Research Leader at the Museum who is looking into the genetics and resilience of different wheat strains.

'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 Matt. '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.'

A photograph of pressed plant specimens on paper in the collection. On the left there is a green grass with seed heads and roots visible, on the right the brown stems and seed heads of another plant.

Some of the specimens in the collection date back 300 years ©The Trustees of the Natural History Museum, London

This is of significance as scientists warn about massive global environmental change, including increases in both land and ocean temperatures, more frequent heatwaves, and an increase in the frequency and intensity of extreme weather events.

In order to continue feeding the world's population on a changing planet, it is now more vital than ever that we develop strains of wheat that are less reliant on these fertilisers and pesticides and that can be grown in harsher climates. 

Sifting through 300 years of collections

The answers to some of these problems may be found in the DNA sequences of museum specimens of wheat and its relatives.

The Museum's own herbarium contains around 8,000 specimens belonging to the Triticeae group of plants, which includes wheat, barley, rye and wild crop relatives. This collection stretches back to the 1700s, covering a period of time that predates modern agricultural practices that changed the genome of the wheat we consume.

It is possible that these ancient specimens 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 at the Museum are now planning sequence the entire genomes of a selection of Museum specimens of wheat and its relatives to discover how the genome has changed through time. But deciding which of the thousands of specimens in the Museum's collections to sequence is something of a challenge. This is where digitisation can play a role. 

A scientist sits at a desk in front of a computer, with a number of pressed plant specimens laid out. In their hand, they hold a scanner which they are pointing at the specimens.

Digitising the Museum's collections allow for specimens to become freely searchable by anyone in the world ©The Trustees of the Natural History Museum, London

'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,' says Matt.  '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 fertiliser.'

Digitising a herbarium specimen is the process of photographing and recording a specimens data before publishing it online. At the Museum, the digitsation team have created a simple workflow with repeatable steps for each specimen to ensure that all the information is captured and published onto the Museum's Data Portal in the quickest way possible.

This information then becomes freely searchable by other scientists or members of the public.

For this project, digitisation means the scientists will have a searchable dataset of Triticeae specimens where they will be able to see the spread of the collection through time and space. This can then be cross referenced with historical information so that the researchers will be able to choose specimens for sequencing from before and after the introduction of agricultural practices (like the use of artificial fertiliser) to then see how the genome of wheat has changed over time.

Digitisation also allows researchers to note down specimens that look like they might be interesting to use for further research. For example, specimens that have 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.

A scientist stands in the collections, with large cabinets either side. In front of them is a trolley with piled high with pressed plant specimens, one of which they are holding in their hands.

By going through the collections, the digitisers are also able to catalog note down any unusual specimens they might come across ©The Trustees of the Natural History Museum, London 

Digitisation can also result in the rediscovery of historically important or interesting specimens. In the course of this project, for example, researchers have found many old specimens from Chelsea Physic Garden which were sent to the Museum in the 1700s, specimens collected by Joseph Banks on Captain Cook's Endeavour voyage of 1768, and approximately 20 type specimens that are the example specimen for which a species is named.

Grains of truth

Digitisation is being used to facilitate whole genome DNA sequencing research as Museum specimens are one of the best ways to get this kind of historical DNA.

After the digitisation is complete, Wheat Through the Ages will start to sequence specimens using next generation sequencing technology. Improvements in genome sequencing and a landmark project in 2020 to sequence ten reference genomes has paved the way for scientists to sequence up to 1500 specimens.

'By sequencing key samples from the digitised database, we can mine tens of thousands of specimens from around the world, and across centuries to find many of these genes,' explains Matt. 'Once we have found the genes we can use relatives with the same genes to breed with our modern wheats, or even use genome editing technology to add these genes directly to modern wheats.'

With the hope of bioengineering more sustainable strains of wheat, having wheat strains that can resist disease and grow in the environments and weather conditions that we are predicted to see more of with climate change could improve food security for a growing global population.  

Wheat Through the Ages is a collaboration between the Museum, Kew Gardens and The Hebrew University of Jerusalem. It is funded through EU SYNTHESYS+ Virtual Access, which works to give scientists access to global collections virtually through as each institution digitises their own specimens, reducing the need for physical travel and international loans. This digitisation on-demand approach means institutions can focus their digitisation efforts on taxonomic groups that scientists are especially eager to research.