Past and Future Use of Wild Relatives in Crop Breeding

TLDR: The role that CWR play in modern crop breeding is documented, including their past and current use, advanced breeding methods and technologies that promise to facilitate the continued use, and what constraints continue to hinder increased use of CWR in breeding.

Abstract: Wild species related to agricultural crops (crop wild relatives, or CWR) can increase the adaptive capacity of agricultural systems around the world. They represent a large pool of genetic diversity from which to draw new allelic variation required in breeding programs. Crop wild relatives have been extremely valuable in adapting crop varieties to changing disease pressures, farming practices, market demands, and climatic conditions. Unfortunately, CWR are a threatened resource and measures need to be taken to protect them, both in the wild and in genebanks. Here, we review how wild species have contributed to the development of improved crop varieties and where efforts must be concentrated to harness their value in the future. Drawing on the results of an extensive literature search, a series of 14 expert consultation meetings, and in-depth interview with experts on 24 crops, we document the role that CWR play in modern crop breeding. We discuss (i) their past and current use, (ii) advanced breeding methods and technologies that promise to facilitate the continued use of CWR, and (iii) what constraints continue to hinder increased use of CWR in breeding. H. Dempewolf, B. Kilian, and L. Guarino, Global Crop Diversity Trust, Platz der Vereinten Nationen 7, 53113 Bonn, Germany; H. Dempewolf, and G. Baute, Univ. of British Columbia, Dep. of Botany, 6270 University Blvd., Vancouver, BC Canada; J. Anderson, Univ. of Hawaii at Manoa, Dep. of Tropical Plant & Soil Sciences, 3190 Maile Way, Honolulu, Hawaii 96822; C. Smith, Univ. of Waterloo, Dep. of Environment and Resource Studies, 200 University Ave. W., Waterloo, ON N2L 3G1, Canada. Received 15 Oct. 2016. Accepted 15 Dec. 2016. *Corresponding author (hannes.dempewolf@croptrust.org). Assigned to Associate Editor Stella Kantartzi. Abbreviations: CSSL, chromosome segment substitution line; CWR, crop wild relative; MAS, marker-assisted selection; QTL, quantitative trait locus; SNP, single-nucleotide polymorphism; WGS, wholegenome shotgun sequence. Published in Crop Sci. 57:1070–1082 (2017). doi: 10.2135/cropsci2016.10.0885 © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA This is an open access article distributed under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Published June 16, 2017