After identification of germplasm, the elite plant material must be collected and conserved. Characterization, evaluation and maintenance of the germplasm are very important, for loss of unique genotypes represents a loss of genetic diversity. Suitable methods of propagation must be available if the material is to be preserved. in vitro propagation is one such technique, and is especially useful for the production of virus-free plants for germplasm repositories, rapid propagation of selected genotypes in breeding programs, propagation of plants for which conventional methods are not available and also for large-scale multiplication of new cultivars. Tissue culture is also used for the international exchange of plant materials. These issues will be addressed with particular reference to temperate zone fruits in the tropics and subtropics (TZFTS).