Editorial: Wild Plants as Source of New Crops

The history of agriculture can be viewed as a series of key events, such as the Neolithic Revolution, post-domestication expansion of agriculture to new regions, secondary domestications of new crops, movement over the Silk Road, the Columbian Exchange, the Industrial Revolution, the Green Revolution and even the more recent, ongoing genomic revolutions.Each of these has had positive benefits, but they have also come at a cost, including to agricultural biodiversity.It is estimated that on the Earth there are between 300,000 and 500,000 species of higher plants, of which approximately 369,000 have been identified or described (Willis, 2017).Many species are still unknown to science, while perhaps a third is at risk of extinction (Pimm and Joppa, 2015) .The number of plant species used for food by pre-agricultural human societies is estimated to be around 7,000, but only a small fraction of the diversity of the plant kingdom has been domesticated.Our present knowledge of domesticated plants largely reflects our experience of a relatively small number of living domesticates adapted to recent, Holocene environments.The process of crop domestication was based on selection driven by human cultivation practices and agricultural environments.Approximately, 2,500 species have undergone some degree of domestication, and 250 species are considered to be fully domesticated, in the sense that their full lifecycle became dependent on human cultivation (Meyer et al., 2012;Gaut et al., 2018;Smyḱal et al., 2018).Humanity relies on a small collection of crop plants such as corn, rice, wheat, soybean, and potato constituting the majority of our dietary intake.Altogether, some 10 to 50 plant species together provide about 95% of the world's caloric intake.This concentration on a few species for most food is a key element of the vulnerability of the world food supply to the impact of climate change and the outbreak of major new plant diseases.Crop wild relatives (CWRs) remain the largest reservoir of genetic diversity for crop improvement and have been utilized for major gene disease and pest resistance, and abiotic stress tolerance (Vavilov et al., 1992;Hajjar and Hodgkin, 2007;Warschefsky et al., 2014;Castañeda-A ́lvarez et al., 2016;Smyḱal et al., 2018;Coyne et al., 2020).However, there remains a large set of plant species from various plant families and genera which have favorable traits but have not been domesticated so far.As we have been gaining knowledge on the genomic and biological background of domestication processes, we can apply more effective selection to domesticate more wild species.Since many wild taxa are locally adapted to particular habitats and contain significant genetic diversity, this might create novel crops and help us to achieve more environmentally sustainable agriculture as we face climate change.Not all candidates for neo-domestication are CWR, although many and perhaps most will be, because the form/function of the related crop species provides a useful template to guide the neo-domestication of the CWR.On the other hand, all of the wild sources of useful genes for introgression into crop species are necessarily Frontiers in Plant Science | www.frontiersin.