The diversity among wild relatives of domesticated crops is currently poorly represented in repositories established to conserve plant biodiversity, reports a paper published online this week in Nature Plants. The study calls for a systematic effort to increase the conservation of the wild relatives of crops by increasing their availability in gene banks for use in plant breeding.

The wild cousins of cultivated plant species possess genetic diversity that may prove useful for developing more productive, nutritious and resilient crop varieties. However, this expectation is based on the assumption that crop wild relatives will be readily available for research and plant breeding, either in the wild or stored in gene banks.

Nora Castaneda-Alvarez and colleagues used occurrence data from biodiversity, herbarium and gene bank databases to model the global distribution of over 1,000 different genotypes of 81 crops, comparing their diversity to that represented in gene banks. They find that the diversity of crop wild relatives is poorly represented, with over 70% identified as having high priority for further collection, and over 95% insufficiently represented with respect to the full range of geographic and ecological variation in their native distributions. They find that the greatest collection deficits occur in the Mediterranean and the Near East, western and southern Europe, Southeast and East Asia, and South America.