State of ex situ conservation of landrace groups of 25 major crops

Authors: RAMIREZ-VILLEGAS, J - International Center For Tropical Agriculture (CIAT); KHOURY, C - International Center For Tropical Agriculture (CIAT); ACHICANOY, H - International Center For Tropical Agriculture (CIAT); DIAZ, M - International Center For Tropical Agriculture (CIAT); MENDEZ, A - International Center For Tropical Agriculture (CIAT); SOSA, C - International Center For Tropical Agriculture (CIAT); KEHEL, Z - The International Center For Agricultural Research In The Dry Areas(ICARDA); GUARINO, L - Global Crop Diversity Trust; ABBERTON, M - International Institute Of Tropical Agriculture (IITA); AUNARIO, J - International Rice Research Institute; AWAR, B - International Centre For Agricultural Research In The Dry Areas (ICARDA); ALARCON, J - International Maize & Wheat Improvement Center (CIMMYT); AMRI, A - The International Center For Agricultural Research In The Dry Areas(ICARDA); Anglin, Noelle; AZEVEDO, V - International Potato Center; AZIA, K - The International Center For Agricultural Research In The Dry Areas(ICARDA); CAPILIT, G - International Rice Research Institute; CHAVEZ, O - International Potato Center; CHEBOTAROV, D - International Rice Research Institute; COSTICH, D - International Maize & Wheat Improvement Center (CIMMYT); DEBOUCK, D - International Center For Tropical Agriculture (CIAT); ELLIS, D - International Potato Center; FALALOU, H - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - Nigeria; FIU, A - Center For Pacific Crops And Trees (CEPACT); GHANEM, M - University Mohammed Vi Polytechnic; GIOVANNINI, P - Global Crop Diversity Trust; GOUNGOULOU, A - Africa Rice Center (AFRICARICE); GUEYE, B - International Institute Of Tropical Agriculture (IITA); HOBYB, A - The International Center For Agricultural Research In The Dry Areas(ICARDA); JAMNADASS, R - World Agroforestry Center; JONES, C - International Livestock Research Institute Ethiopia; KPEKI, B - Africa Rice Center (AFRICARICE); LEE, J - International Rice Research Institute; MCNALLY, K - International Rice Research Institute; MUCHUGI, A - International Livestock Research Institute Ethiopia; NDJIONDJOP, M - Africa Rice Center (AFRICARICE); OYATOMI, O - International Institute Of Tropical Agriculture (IITA); PAYNE, T - International Maize & Wheat Improvement Center (CIMMYT); RAMACHANDRAN, S - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India; ROSSEL, GENOVEVA - International Potato Center; ROUX, NICOLAS - Bioversity International; RUAS, MAX - Bioversity International; SANSALONI, CAROLINA - International Maize & Wheat Improvement Center (CIMMYT); SARDOS, JULIE - Bioversity International; SETIYONO, TRI DERI - International Rice Research Institute; TCHAMBA, MARIMAGNE - International Institute Of Tropical Agriculture (IITA); VAN DEN HOUWE, I - Center For Biodiversity, Functional & Integrative Genomics; VELAZQUEZ, J - International Maize & Wheat Improvement Center (CIMMYT); VENUPRASAD, R - International Rice Research Institute; WENZL, PETER - International Center For Tropical Agriculture (CIAT); YAZBEK, M - International Center For Agricultural Research In The Dry Areas (ICARDA); ZAVALA, C - International Maize & Wheat Improvement Center (CIMMYT)

Submitted to: Nature Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2022
Publication Date: 5/9/2022
Citation: Ramirez-Villegas, J., Khoury, C.K., Achicanoy, H., Diaz, M.V., Mendez, A.C., Sosa, C.C., Kehel, Z., Guarino, L., Abberton, M., Aunario, J., Awar, B., Alarcon, J.C., Amri, A., Anglin, N.L., Azevedo, V., Azia, K., Capilit, G.L., Chavez, O., Chebotarov, D., Costich, D.E., Debouck, D.G., Ellis, D., Falalou, H., Fiu, A., Ghanem, M.E., Giovannini, P., Goungoulou, A., Gueye, B., Hobyb, A.I., Jamnadass, R., Jones, C.S., Kpeki, B., Lee, J., McNally, K.L., Muchugi, A., Ndjiondjop, M., Oyatomi, O., Payne, T.S., Ramachandran, S., Rossel, G., Roux, N., Ruas, M., Sansaloni, C., Sardos, J., Setiyono, T., Tchamba, M., van den Houwe, I., Velazquez, J.A., Venuprasad, R., Wenzl, P., Yazbek, M., Zavala, C. 2022. State of ex situ conservation of landrace groups of 25 major crops. Nature Plants. 8:491-499. https://doi.org/10.1038/s41477-022-01144-8.
DOI: https://doi.org/10.1038/s41477-022-01144-8

Interpretive Summary: Cultivated landraces of agricultural crops are important targets for collecting and subsequent deposition into long term conservation because they harbor novel genetic combinations which can greatly aid breeding and research programs worldwide. Genetic erosion of landraces has been occurring over time due to population growth, changes in land use, loss in natural conditions due to environmental influences, and other factors. Internationally, there has been a call to prioritize collecting and conservation of landraces before they are lost forever for the benefit of mankind. Genebanks aim to preserve and maintain crop plants long term and make them readily available for research, breeding, and education. However, little is known about how many genetic gaps currently exist in genebank collections globally and how much more collecting of landraces is required for each crop. In this work, scientists examined the information associated with 25 different crops and evaluated their overall representation in genebank collections along with predicting target areas for priority collecting based on genetic gaps observed. Several crops evaluated were found to be well represented in germplasm collections, while others (pearl millet, yam, finger millet, groundnut, potato, and pea) had large genetic gaps in genebanks and are recommended for priority collecting and long-term conservation. This work provides a knowledge base for scientists to find and target key genetic gaps in crop plants, as well as, point specifically to the countries and areas for collecting valuable crop germplasm.

Technical Abstract: Crop landraces provide unique local agro-ecological and societal functions and services, and represent important genetic resources for plant breeding globally. Despite many decades of concern over the erosion of their diversity, and, in response, sustained efforts to conserve landraces in ex situ repositories, the degree to which these cultivated populations are protected and available for use remains poorly understood. Here we modelled the potential distributions of landraces of 25 cereal, pulse, and starchy root, tuber, and fruit crops within their geographic regions of diversity worldwide. We then analyzed the extent to which the genetic diversity of landraces are represented in genebank collections using geographical coverage as a proxy for coverage of genetic diversity. We find that ex situ conservation is currently moderately comprehensive on average, with substantial variation among crops (mean of 63% ± 12.6 of distributions represented ex situ). Breadfruit, banana and plantain, lentil, common bean, chickpea, barley, and bread wheat landraces are among the most fully represented, while the largest conservation gaps persist for pearl millet, yam, finger millet, groundnut, potato, and pea. Geographic areas identified as priorities for further collecting of landraces are concentrated in hotspots in South Asia, the Mediterranean and West Asia, Mesoamerica, West, East, and Southern Africa, the Andean mountains of South America, and in Central and East Asia. With further progress made to fill these gaps, a high degree of representation of landrace diversity in genebanks globally is feasible, thus fulfilling international targets regarding their ex situ conservation.