Crop Wild Relatives (CWR), the wild and weedy cousins of our important crop plants, are increasingly appreciated for their contributions through crop breeding to improving crops’ resilience and productivity. Their usefulness particularly in adapting to environmental extremes may prove vital in the coming century.
After two years of gathering data from the world’s herbaria, genebanks, and experts on the distribution of CWR plants, a team of researchers led by the International Center for Tropical Agriculture (CIAT) has begun to produce results displaying the distribution of CWR and their conservation concerns. These results will inform subsequent collecting efforts under the “Adapting Agriculture to Climate Change: Collecting, Protecting, and Preparing Crop Wild Relatives” Project, led by the Global Crop Diversity Trust and the Millennium Seed Bank, Royal Botanic Gardens, Kew.
“Gap analysis” results have been completed for nearly 500 CWR taxa related to 29 globally important crops, including maps displaying distributions, patterns of richness, and areas worldwide where CWR are particularly in need of collecting for conservation and in order to be made accessible for breeding efforts.
The gap analysis methodology results in a final priority score given to each taxon analyzed. This score is derived from the average of three quantitative assessments utilized to estimate the comprehensiveness of germplasm collections for the taxon (see our PLoS One article for details on the methodology):
- Sampling Representativeness Score: estimates overall sufficiency of number of genebank accessions held
- Geographical Representativeness Score: estimates the sufficiency of geographic coverage of genebank accessions in comparison to the overall distribution of the taxon
- Environmental Representativeness Score: estimates the sufficiency of genebank accessions in comparison to the environmental diversity encompassed in the overall distribution of the taxon.
Of the 485 taxa analyzed, 280 (58%) were classified as High Priority Species (HPS) for collection, 83 (17%) as Medium Priority Species (MPS), 98 (20%) as Low Priority Species (LPS), and only 24 (5%) as not in need of conservation efforts (NFCR) (Fig. 1).
Experts on the taxonomy and distribution of these CWR are reviewing the results. Meanwhile, CIAT researchers are preparing to complete similar analyses on an additional 600 taxa related to 60 other globally important crops.
The global distribution of the CWR of the 29 assessed crop gene pools are displayed in Figs 2-3. Fig. 2 displays the global richness of the CWR taxa, which is largely concentrated in the traditionally recognized centers of crop diversity i.e. the ‘Vavilov Centres’, particularly the Near East. Due to the choice of crop gene pools in the project, particularly sunflower and pigeonpea, significant richness is also seen in a number of regions that are not traditionally recognized as major centers of crop diversity, such as the eastern United States and northern Australia.
Fig. 3 illustrates the richness of taxa/areas that are in need of collection for all HPS in all assessed crop gene pools. Particularly rich gap areas include West, East and Southern Africa, the Indian subcontinent, Australia, and the United States.
Interactive maps displaying the distributions and conservation concerns of these CWR will soon be available on the Project website.
Post by Vivian Bernau, Visiting Researcher at CIAT