Role of Plant Genetic Resources in Food SecurityR JReddenauthorH DUpadyayaauthorS LDwivediauthorVVadezauthorMAbbertonauthorAAmriauthorWithin the last 13 000 yearsmany crop species were domesticated and spread to a range of agri-ecological environments, varying by species (Hancock 2012a).There was manual selection for both food and agronomic characteristics, and natural selection for adaptation to new agro-ecological environments. Such selection was affected by available gene pools, continuing sources of genetic diversity from wild relatives andmutations, natural selection pathways fromstabilising to directional, and both allo- and auto-polyploidy, to result in unique gene pool patterns for each crop (Hancock, 2012b; Cortes et al., 2013). Thedistribution of wheatwas expanded greatlywith the addition of the Aegilops tauschii D genome to tetraploid durum wheat, thereby enabling hexaploid wheat to adapt to a much wider agroecological range from the subtropics to high latitudes, and to provide a wider diversity of food uses (Hancock, 2012c)...MilletsGenetics and GenomicsGermplasmGene Bank2019John Wiley & SonsBook Section