Biotechnology has brought about a revolution in the way that plant genetic resources can be utilized. Clonal crops cover a wide range of species from the root and tuber crops, such as potato, cassava, yam, taro and sweet potato, to fruits, such as apple, pear, citrus, banana and the cooking banana (plantain). Other miscellaneous crops including vanilla, ginger, turmeric, hops and sugarcane are also clonally propagated. In some of these cases, seed production is impossible due to sterility. In others, it is undesirable to produce seeds for conservation as this would break up highly heterozygous clonal genotypes. The foundation technologies that make up an in vitro conservation system are collection, disease eradication and indexing, culture initiation, multiplication, storage and distribution. There are two basic options for in vitro storage, slow growth for the short to medium term and cryopreservation for the long term. (Since the defi nition of storage time-span and the concepts of active or base storage derive strictly from motivation rather than methodology, there is no reason why, in fact, cryopreservation should not have applications in short-to medium-term conservation.) Intensive conservation efforts are needed for clonally propagated crops, constituting about 1,000 species, and for diffi cult-to-store seeds, constituting about 88,250 species throughout the world. In vitro approaches, including tissue culture maintenance and cryopreservation,
