IN VITRO GERMPLASM CONSERVATION

Abstract

In vitro techniques have great potential for collecting, exchange and conservation of: i) genetic resources of recalcitrant-seed and vegetatively propagated species as well as of endangered species; ii) elite genotypes which are multiplied on a large scale in production laboratories; iii) cultures with special attributes, eg, metabolite-producing cell lines and genetically engineered material. In vitro collecting techniques, which consist of introducing embryos or vegetative tissues in vitro under field conditions, have been developed for collection of germplasm of various problem species. In vitro cultures are routinely used for exchange of plant genetic resources of a number of species, due to their advantages in terms of phytosanitary status and reduced cost. Slow growth techniques have been developed for medium-term conservation of numerous species but their routine use is still restricted to a limited number of crop species. Routine use of cryopreservation is mostly restricted to conservation of cell lines in research laboratories. However, simple and efficient freezing protocols have been developed recently for apices and embryos, and can be considered operational for an increasing number of species. Current research priorities include: i) the development of in vitro collecting techniques for additional species; ii) demonstration of the flexibility, simplicity and practicality of slow growth storage to increase its utilisation; iii) experimentation of existing cryopreservation techniques on a large scale in a genebank context and the development of cryopreservation protocols for additional species.