Interdependence Among Countries in Crop Genetic Resources Provisioning National Food Supplies and Production Systems.

The crops that feed the world originated in specific geographic regions across the planet. Genetic diversity within these crops and their wild relatives is considered to be historically particularly rich within these regions. These genetic resources are regularly employed in crop improvement: thus, preventing erosion of remnant genetic diversity occurring in situ, and ensuring the long-term access to this diversity conserved in genebanks ex situ, are critical to continued increases in agricultural productivity. The geopolitical significance of the geography of crop genetic diversity has not been quantified. Here we report on an assessment of the degree to which the food supplies and production systems of countries worldwide are comprised of crops from each of these regions of diversity. We examine dependence of countries upon crops from regions of diversity other than their own (“foreign crops”), and determine change in this dependence over the past 50 years. Crop diversity hotspots occur across the tropics and subtropics, extending into temperate regions in both hemispheres. National food systems are thoroughly interconnected worldwide in regard to the geographic origins of crop diversity. Countries are highly dependent on foreign crops in their food supplies (68.7% as a global mean across food variables) and in their national production systems (69.3%). This reliance is evident even in countries located in regions of high indigenous crop diversity and has increased significantly over the past half century, bolstering the importance of effective national and international policies to promote genetic resource conservation and exchange.