Humans derive almost 60% of their calories and proteins from three species of plants, viz. maize, wheat and rice. Rice is an important staple food for millions of people, and a large number of wild species and landraces of rice remain to be developed. Protection of such biological diversity is critical for the breeding of improved varieties with higher yield and/or resistance to pests and diseases.
Ex-situ conservation of both wild species and genetic resources of wild crop relatives, wild plants and domestic animal breeds useful for food production should be encouraged whenever they cannot be conserved in situ or when their conservation in situ is under serious threat.
Food plants exemplify the most fundamental values of biodiversity. Originally, plants were consumed directly from the wild, and gathering of wild produce continues throughout the world today. Only a few of the many species of flowering plants have been treated as direct food sources though others provide food for animals which in turn are hunted or farmed by people.
Around 200 species have been domesticated as food plants, and of these about 20 are crops of major international economic importance. Relatively few botanical families account for the world's main food plants: Gramineae (grasses, including cereals) and Leguminosae (legumes, including peas, beans and lentils) are foremost among these.