Stack of harvested wheat in the central Pelopà?nisos. - - FAO Wheat Exploration Mission.. In July 1969, Erna Bennett, Genetic Conservation and Information Specialist from the Crop Ecology and Genetic Resources Branch of the Food and Agriculture Organization of the United Nations (FAO), carried out a mission in Greece to search for and collect primitive wheat varieties native to the mountains and valleys of that country. These primitive wheat strains are one of the world?s richest storehouses of the genetic characteristics that plant breeders require. They are used to adapt desirable characteristics from crops as old as agricultural man into new high-yielding varieties. But old strains are being swamped by the spread by the spread of modern varieties, and in certain areas ? and in the case of certain crops ? emergency measures are necessary to collect these old strains before they disappear completely. FAO and other leading international crop improvement organisations are increasingly concerned with the conservation of primitive crop strains, in whose amazing diversity hides the promise of better crops to come.