Bananas originated in South and Southeast Asia, and are now produced throughout the world’s tropics and eaten in at least 192 countries worldwide. Quinoa came from the South American Andes, and is currently cultivated in almost 100 nations. Countries clearly depend on one another’s crop diversity. But can we measure the extent of the benefits?

An International Treaty built on interdependence

The only new International Treaty so far agreed this millennium, the International Treaty on Plant Genetic Resources for Food and Agriculture is based on a concept that may seem obvious and yet is very difficult to measure – countries benefit from another’s crop diversity.

Interdependence among countries is so foundational to the Treaty that it is mentioned in the preamble, which outlines its rationale:

“Cognizant that plant genetic resources for food and agriculture are a common concern of all countries, in that all countries depend very largely on plant genetic resources for food and agriculture that originated elsewhere;”1

This short sentence is dense with important tenets: a) that crop diversity is valuable to food and agriculture; b) that the origins of that diversity – the geographic locations where crops were initially domesticated and evolved over long periods of time – are particularly important sources of genetic resources; c) that all countries around the world need this diversity to maintain agricultural productivity; and d) therefore that all countries have an interest in the conservation and open exchange of this diversity.

These tenets are self-evident for those who work with genetic resources and consider themselves students of N.I. Vavilov. But how true are they? Where is the present-day evidence for interdependence among countries? How much do countries really need each other at this point in human history?

Just how interdependent are countries?

Evidence of massive change in recent decades in the ways that countries feed themselves clearly support the argument that existing food systems are interdependent. Trade in food across national boundaries has been increasing2-5. Bananas are eaten in at least 192 countries, on every continent6. Around the world people are eating much more similarly, with an ever greater proportion of diets composed of products made from a relatively small range of staples including wheat, rice, sugar, maize, potato, soybean, and oil palm7.

Global interdependence in trade in agricultural commodities is pretty clear. But what about interdependence among countries at the level of focus of the Plant Treaty, that is, genetic resources?

Unfortunately, data on the amount of exchange of plant genetic resources across national borders are not as easy to come by as statistics on commodity trade. A global information system revealing distributions from genebanks to specific recipients does not yet exist, and not all genebanks are in the practice of making such data available. Some genetic resource users prefer that their requests be kept confidential, especially those in the private sector. Perhaps most importantly, there is no comprehensive way to track what requested genetic resources have actually contributed to the creation of new crop varieties that have ultimately affected farmers’ and consumers’ lives. Thankfully, the information mechanism being created by the Plant Treaty itself is making it more feasible to understand the global impact of germplasm distributions. But countries will need to agree to openly share distribution information with the public for it to work.

On the other hand, there is published evidence for increasing international distributions over time by the CGIAR genebanks and the U.S. National Plant Germplasm System8-11. There is also good data on the use of breeding materials from diverse geographic backgrounds in the development of modern varieties of cereal and grain legume crops12-17. In addition, most of the largest producers of major crops are located far from the geographic origins of these plants, e.g. China, India, USA, Russian Federation, France and Canada for wheat; USA, China, Germany, France, Brazil, and Argentina for maize; USA, Brazil, Argentina and India for soybean; and China, India, Russian Federation, Ukraine, and USA for potato6,18. Case studies and general indications thus show that countries are likely using more “exotic” genetic diversity over time.

How about an estimate of interdependence among countries?

A few years ago, during a deep dive into the philosophical underpinnings of the Plant Treaty, I began to investigate how the argument that countries are interdependent was successfully made in the absence of comprehensive information on exchange of crop diversity across borders. One part of the answer lies in a study carried out a few years before the Plant Treaty was born by Bolivian scientist Ximena Flores-Palacios, and written up in 1998 for the FAO Commission on Genetic Resources for Food and Agriculture.

The purposely cautiously titled “Contribution to the Estimation of Countries’ Interdependence in the Area of Plant Genetic Resources” examined the most important food crops contributing to calories in countries’ food supplies, and identified the “primary regions of diversity” of each of these crops19. Flores-Palacios then derived, for each country, a metric of how much of its calories come from crops whose primary regions of diversity are located elsewhere around the world. The results showed that most countries worldwide largely get their calories from crops whose origins are located in distant regions. This was a helpful, if general, indication of interdependence, which contributed to the background information used in the early negotiations of the Plant Treaty.

Almost 20 years later, there is still a need for clear information regarding interdependence among countries on plant genetic resources. Over 130 nations around the world have become Contracting Parties to the Plant Treaty, but a number of countries located in regions of rich historical crop diversity, and even some of the world’s top agricultural producers, have yet to ratify it. Many aspects of implementation, including the benefit sharing mechanism and the interpretation of Farmers’ Rights, are being actively discussed without clear resolution. And the list of crops whose genetic diversity is covered under the Multilateral System of Access and Benefit Sharing is clearly not yet representative of all the important food crops around the world (more on that later).

Over the past two years, Flores-Palacios, myself, and a large team of researchers created a new estimation of interdependence among countries on genetic resources, based not only on what countries consume (measured in terms of calories, protein, fat, and food weight) but also, and perhaps more pertinent to the Multilateral System, what they produce (measured in terms of total national production quantity, harvested area, and monetary value of production)18. Using food supply and agricultural production data provided by FAO, we analyzed all 151 crops and all 177 countries reported in the data, drawing upon the historical and contemporary literature on centers of origin and diversity of crops as well as geographic distributions of their wild relatives20 to create a modern understanding of the primary regions of diversity of crops, which we defined as “areas typically including the locations of the initial domestication of crops, encompassing the primary geographical zones of crop variation generated since that time, and containing relatively high species richness in crop wild relatives.”18 (Figure 1).



Figure 1: Primary regions of diversity of major agricultural crops worldwide. Note that crops can belong to more than one primary region of diversity.

All of our metrics indicated that countries indeed produce and/or consume crops from many different primary regions of diversity located around the world (Figure 2). We built an interactive website that enables a thorough exploration of the intricate connections among regions.



Figure 2: Links between the primary regions of diversity of crops and their current importance in regional food supplies, measured in terms of calories (kcal/capita/day), protein (g/capita/day), fat (g/capita/day), and food weight (g/capita/day). Each region has a color representing its own native crops and those colors are connected to other regions due the importance of those crops in the diets of other regions. The direction of the contribution is indicated by both the native region’s color and a gap between the connecting line and the consuming region’s segment. The magnitude of contribution is indicated by the width of the connecting line. Regional food supply values (per capita/day) were formed by deriving a weighted average of national food supply values across countries comprising each region, with national values weighted by population.

We also carried out an updated estimation of the degree to which countries cultivate and/or eat “foreign” or “exotic” crops, i.e., plants whose primary regions of diversity do not overlap at all with the region(s) where the country is located (Figure 3). As a global average, 65.8% of plant-based calories, 66.6% of protein, 73.7% of fat, and 68.7% food weight come from foreign crops, and 71.0% of total production quantity, 64.0% of harvested area, and 72.9% of production value are of foreign crops. Looking at variation among countries, we found that greater utilization of foreign crops was correlated with higher dietary diversity and GDP21.

Figure 3: Use of foreign crops per country, as measured in quantity (tonnes) of national agricultural production. Scale is degree of foreign crop use (1 = 100% use of foreign crops).

Perhaps most importantly, we found that no country is independent with regard to the primary regions of diversity of the crops it produces or consumes, not even those located within the most ancient and richest primary regions of diversity, e.g., West Asia. Examining change over time in the use of foreign crops, we found that use increased as a global trend over the past 50 years in concert with economic and agricultural development and the globalization of food systems, with fat, production value, production quantity, and food weight increasing the most. The greatest increases were seen in countries in Africa; West, South, Southeast, and East Asia; Central America; and Andean and tropical South America. Data for every country is available in the supplementary tables.

But does an estimate reflect true interdependence?

A number of limitations of the study should be noted. The diversity of crops is not reported in FAO data at high enough resolution to distinguish all contributing plant species in all countries. Therefore, we certainly underestimated total food diversity, especially in countries with heterogeneous topographies, diverse food cultures and coarse agricultural and dietary intake reporting. Also, our defined primary regions of diversity were fairly large and (unnaturally) aligned with country political boundaries, and these primary regions of diversity for some crops are still being refined (e.g., watermelon). More investment in country-level agricultural production and food intake data and further research into the origins of food crops are needed to improve the analysis.

Further, formal seed system development and plant breeding capacity vary considerably among countries, meaning that nations have differential potentials to benefit from importing and using crop genetic resources22. Decreasing funding for public breeding programs in most regions, with correlated increases in the importance of the private sector22-23, also complicates directly correlating countries’ production of foreign crops to their dependence on access to foreign genetic resources for breeding.

Finally, while increasing interest in utilization of the wild relatives of crops for plant breeding, and their relatively low level of representation in genebanks,20 validate present-day interdependence between the countries producing foreign crops and those crops’ primary regions of diversity (where crop wild relatives are concentrated), the situation with regard to domesticated plants is less straightforward. The geographic range of crops has expanded well beyond primary regions of diversity, with new forms and combinations of genetic diversity in these crops having been developed wherever farmers and plant breeders have been activee.g.,24-27. International, regional, and some national genebanks also maintain substantial collections of foreign crop genetic resources. Availability and access to the variation conserved in these more recent hotspots of crop diversity is determined not only by national and international policy, but also by the accessibility of information regarding collections and the available resources to adequately conserve and fulfill requests for distributions. Which is why the Crop Trust endowment and information systems such as Genesys are so important.

Interdependence and the state of the Plant Treaty

While acknowledging these complexities, it is still clear that all countries use food crops whose genetic diversity is largely concentrated outside their borders, and therefore potentially benefit from international collaboration to access plant genetic resources. The very likely trend is for this to increase over time, especially as consumer’s preferences change and as plant breeders look for sustainable ways to overcome production challenges such as natural resource limitations28 and climate change29.

The implications of these results are highly aligned with the letter and spirit of the Plant Treaty, as the broad use of foreign crops and the extensive interconnectedness among countries worldwide bolsters the arguments:

For increasing international collaboration on conservation and access to the genetic diversity of food crops;

For considering the genetic resources of important food crops as public goods which should be openly available to all;

For making exchange of genetic resources as administratively straightforward and financially low-cost as possible; and

For respecting Farmers’ Rights to practice traditional methods of conservation and exchange, not only in recognition of their historical contributions to the diversity in our food systems, but also in active support of a primary medium by which crop diversity is generated in the present and future.

One direct outcome of our research was the finding that Annex 1, the negotiated list of plant genetic resources covered under the Multilateral System “according to criteria of food security and interdependence”1, is not sufficiently inclusive with regard to the most important food crops globally. The present list focuses on cereal, pulse, starchy root, and forage crops, with oil crops, vegetables and fruits largely ignored. We found that 28.7% of calories from plants in global aggregate food supplies, 19.0% of protein, 61.0% of fat, and 43.4% of food weight derive from crops not currently covered in Annex 1. Likewise 41.0% of total global production quantity, 27.0% of harvested area, and 41.2% of global production value are of crops not currently covered. That’s a lot of food.

What are the main gaps? The spider webs in Figure 4 offer a quick way to compare the global importance of the crops specifically reported in FAO data, based on our four metrics for consumption and three for agricultural production. The larger the web, the more important the crop globally. Blue outlined crops are already covered in Annex 1 of the Plant Treaty; red outlined crops are not.

Figure 4: Relevance of crop commodities in global food supplies and agricultural production systems worldwide, and their coverage in Annex 1 of the International Treaty on Plant Genetic Resources for Food and Agriculture. Crops were assigned importance individually for each variable into 10% quantiles, from 1 (low importance) to 10 (high), based upon their global aggregate food supplies and total global agricultural production values. The center of the web is equivalent to 1; the outside of the web to 10 in importance. All specific crops are displayed; 20 general commodities are not shown here. Ani-Fen-Cor denotes anise, badian, fennel and coriander treated together; Mango Guav denotes mangoes, mangosteens and guavas; and Nut Card denotes nutmeg, mace and cardamoms. Blue outlines identify crop commodities covered in Annex 1, while red are not covered.

Chili, cacao, cottonseed, cucumber, garlic, grape, groundnut, lettuce, olive, onion, oil palm, pumpkin, soybean, spinach, sugarcane, tomato, and watermelon are some of the most important crops not yet covered in Annex 1. And yet there are more gaps to mention, such as the wild relatives of cassava and maize, some of the most important crops to food security in challenging agricultural regions. And then there are up-and-coming crops like quinoa, which don’t yet show importance well in FAO data, but are being cultivated in almost 100 countries30. The Plant Treaty has done a lot to formalize the understanding that countries need each other for genetic resources, but the latest data suggests that there is still a way to go to reach a comprehensive global system for facilitated access to important crop diversity.

The full article “Origins of food crops connect countries worldwide” was published open-access in Proceedings of the Royal Society B. An interactive website of the results and data per country are also available.

This article was originally posted on the Global Crop Diversity Trust website.

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