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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Agricultural Genetic Resources Preservation Research » Research » Publications at this Location » Publication #386362

Research Project: Efficient and Effective Preservation and Management of Plant and Microbial Genetic Resource Collections

Location: Agricultural Genetic Resources Preservation Research

Title: Crop genetic erosion: Understanding and responding to loss of crop diversity

item KHOURY, COLIN - St Louis University
item BRUSH, STEPHEN - University Of California, Davis
item COSTICH, DENISE - International Maize & Wheat Improvement Center (CIMMYT)
item CURRY, HELEN ANNE - University Of Cambridge
item DEHAAN, STEPH - International Potato Center
item ENGELS, JMM - Bioversity International
item GUARINA, LUIGI - Global Crop Diversity Trust
item HOBAN, SEAN - Morton Arboretum
item MERCER, KRISTIN - The Ohio State University
item MILLER, ALLISON - St Louis University
item NABHAN, GARY - University Of Arizona
item PERLALES, HUGO - Colegio De La Frontera
item Richards, Christopher
item RIGGINS, CHANCE - University Of Illinois
item THORMANN, IMKE - Federal Office For Agriculture And Food

Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/13/2021
Publication Date: 9/13/2021
Citation: Khoury, C., Brush, S., Costich, D., Curry, H., Dehaan, S., Engels, J., Guarina, L., Hoban, S., Mercer, K., Miller, A., Nabhan, G., Perlales, H., Richards, C.M., Riggins, C., Thormann, I. 2021. Crop genetic erosion: Understanding and responding to loss of crop diversity. New Phytologist. 233(1):84-118.

Interpretive Summary: The term genetic erosion has been used in various contexts to describe the loss of genetic variation over time in wild species and crops. In this comprehensive review of the literature, we describe the ways these definitions have been used and focus particularly on its application to crop species. We synthesize the common features of genetic changes over time and propose steps to better account for these changes in natural habitats and in off site collections. Establishing baseline data allows for more precise estimates of change through regular monitoring and may help as early warning data to prevent further loss.

Technical Abstract: Crop diversity underpins the productivity, resilience, and adaptive capacity of agriculture. Loss of this diversity, termed crop genetic erosion, is therefore concerning. While alarms regarding evident declines in crop diversity have been raised for over a century, the magnitude, trajectory, and drivers remain insufficiently documented and poorly understood. We outline the various definitions, measurements, scales, and sources of information on crop genetic erosion. We then provide a synthesis of the evidence regarding changes in the diversity of traditional crop landraces on farms, modern crop cultivars in agriculture, crop wild relatives in their natural habitats, and crop genetic resources held in conservation repositories. This evidence indicates that marked, complex change in diversity has occurred in all these contexts, the magnitude depending on species, taxonomic and geographic scale, and region, as well as analytical approach. We discuss steps needed to further advance knowledge around the agricultural and societal significance, as well as conservation implications, of crop genetic erosion. Finally, we propose actions to mitigate, stem, and reverse losses of crop diversity.