A geographical area where a plant species, first developed its distinctive properties (in farmers’ fields or in the wild). Crop diversity – the variation between and within crops and between crops and wild relatives – is a treasure that has been developed and nurtured by thousands of generations of farm families and provides the building blocks of food security and rural development. Mesoamerica, for example, is the centre of origin of maize. Africa is a centre of origin for coffee and for a range of cereal crops such as sorghum, pearl millets, finger millets, and African rice. It is also a secondary centre of diversity for temperate crops such as barley and wheat. Current and future global food security depends on the protection of biodiversity in these areas and the farming communities that sustain it. For example, North American barley was decimated in the 1950s in Canada and the U.S. following an outbreak of yellow dwarf virus. These crops were saved thanks to resistant genes found in an Ethiopian barley variety