Centres of diversity (“gene-centres”) are areas where wild crop ancestors developed and adapted themselves throughout the ages to what were to become their natural habitats. In these areas, in order to survive as a crop species, coevolution between parasites and host plants and between the environment and plant species in general, took place and cultivation of the better adapted native cultivars commenced (Hawkes 1971).

The rich genetic heritage of the gene pool in these areas is of immense importance to plant scientists and plant breeders who are concerned with the incorporation of resistance to pests and diseases, the improvement of quality characters, and a wider environmental adaptability of cultivated varieties.

Plant extinction is a serious threat in many areas of diversity, due among other things to the introduction of new varieties possessing a narrow genetic base (Hawkes 1979), thus lacking the adaptability of the original flora. Fortunately this “genetic erosion” has attracted considerable interest, particularly throughout the 1960s and 1970s, not only from plant geneticists and taxonomists, but also from governments and official bodies. Increasing concern has resulted in greater efforts to preserve this “treasure of nature”.

Inseparably linked to the preservation of this genetic diversity should be its utilization for the continued improvement of cultivatable varieties: without preservation its utilization is impossible, and without utilization preservation becomes meaningless.