II.1 Cryopreservation of Allium sativum L. (Garlic)

The genus Allium comprises about 700 species. Several of them are important vegetables, spices and medicinal plants. The most important crop species are onion and shallot, Allium cepa L., garlic, Allium sativum L., leek, Allium ampeloprasum L. s.l., bunching onion, A. fistulosum L., chives, A. schoenoprasum L., Chinese chives, A. tuberosum Rottl. ex Spr., and rakkyo, A. chinense G. Don. Many other species are collected from the wild as spices or vegetables, or they are planted as ornamentals. Vegetative propagation is predominant in some of these species either because no seeds are set (garlic, great-headed garlic, rakkyo) or because of tradition, as in shallots. Seed-sterile hybrids are used as vegetables (top onions, gray shallots) or in the breeding of new ornamentals (as in subgenus Melanocrommyum). In all such cases, vegetative maintenance of genotypes is necessary. Due to continual vegetative propagation, virus occurrence is common in garlic. Meristem culture allows production of virus-free lines and, hence, is able to circumvent this problem as long as the material is kept permanently in vitro. In vitro storage is, therefore, preferable for this vegetatively propagated material. Although today’s garlic is a clonal crop, it underwent an intensive phase of diversification in the past before it lost its fertility and after that, perhaps, by mutation. Thus, there are some distinctly diverse groups within this species. Discriminating morphological characters are such as the structure of the bulb (arrangement, number and size of the cloves) and the ability to form inflorescences (the height of the inflorescence stalk, position, number and size of inflorescence bulbils and number of flower buds). The most original group has often been considered a separate species, i.e., A. longicuspis Rgl., but there are no morphological characters that separate these forms from true garlic. The present results of DNA analyses support these observations. Therefore, the previous opinion can no longer be followed (Maass and Klaas 1995; Maass 1996;Al-Zahim et al. 1997).This recently so-called longicuspis-group possesses high stalks with well-developed inflorescences, in which a high number of small bulbils are formed together with many flower buds. This group is located in