Global origins of local food favourites

Crops sold in the daily market in Lushoto, Tanzania (Image: Manon Koningstein/CIAT)Image copyright

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The study found that no national diet consisted solely of native crops, highlighting the interconnectedness of the global food system

Italy’s tomatoes and Thailand’s potent chillies, although closely associated with these nations, originate from elsewhere, a study shows.

The assessment of more that 150 key food crops shows how agriculture and diets rely on crops from other regions.

The authors say the results highlight the interdependence of food systems and the need for a united effort to ensure its resilience to future threats.

The findings appear in the journal Proceedings of the Royal Society B.

The research by an international team of scientists assessed the diet and crop production of 177 counties, which accounted for 98% of the world’s population.

Growing understanding

“For probably a hundred years or so, scientists have been bringing together information to know where crops came from, where they were domesticated by diverse agricultural cultures,” said co-author Colin Khoury, a crop diversity specialist from the Colombia-based International Center for Tropical Agriculture.

“It has taken a lot of information to come together, including linguistics, genetics and archaeological data, in order to reach this level of understanding.”

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Italian tomatoes… or are they?

Dr Khoury said a major figure in the understanding of where our food came from was a Russian scientist called Nikolai Vavilov, “a character that would make Indiana Jones look like a bit of a wimp”. He was jailed on numerous occasions by warlords during his expeditions across five continents.

The information Vavilov gathered during his travels allowed him to record the diversity of a wide range of crops, and where the plants were growing alongside their wild relatives.

This led to him proposing “centres of origin” for food crops, which included Central America, South America, the Mediterranean and the Near East, explained Dr Khoury.

Since then, scientists have debated and built upon this body of work, with “centres of diversity” replacing Vavilov’s “centres of origin” hypothesis.

“A century later, people are still arguing about where exactly the crops come from but we know pretty well the regions where the diversity is richest,” he added.

“This is important now for agriculture because that diversity is still used to breed pest and disease resistance, climate change tolerance and all kinds of other things.”

Food web

Dr Khoury said his team’s study was the first to look at where all the crops came from and to ask which areas where important in terms of modern food systems.

The team identified 23 food-producing regions, all of which were deemed to be important, highlighting the global interdependence of the food crops.

“The connections between where people grow and eat food and where they come from are incredibly extensive, nations generally connect to so many different regions around the world.”

Dr Khoury said the findings – as well as confirming the importance of regions, such as the Near East, which were long believed to be key hubs for the origins of food crops – also highlighted that other regions were equally important, such as North America and West Africa.

Another main finding was that no country’s diet consisted wholly of native food crops.

As the global food system is projected to come under increasing pressure from a rising human population and climate change, the findings also pointed to the need for an interconnected effort to ensure food production’s resilience to future threats.

“It is very clear in science that genetic diversity is the biological base for being able to survive and adapt,” Dr Khoury observed.

“So if I am a plant breeder and I want potatoes to be resistant to a new pest in Europe, where do I find that diversity? The quick answer is where the diversity is most diverse, where there is the most variation.

“The argument is that where the potatoes have been the longest, where they have spent hundreds or thousands of years being in contact with different pests, diseases and climates – they are going to be the most diverse.

“These are areas we call primary regions of diversity. It is not just the crops; it is also their wild and weedy cousins.

“The reality is that the diversity is out there in the wild but it is not very well collected, especially when it comes to the wild relatives.”

As for the origins of Italy’s tomatoes and Thailand’s chilli’s?

“Both of those crops are from the new world, from the Americas. It was only after what is called the Columbian exchange,” Dr Khoury explained.

This was the period following Christopher Columbus’s 1492 arrival in South America that saw the transfer of animals, plants, culture and technology between Europe and southern America.

“They saw these crops and brought them back to Europe. It is surprising how quickly new foods were accepted and adopted as their own by cultures.”

Follow Mark on Twitter: @Mark_Kinver

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