Storage of Free Pollen, Pollen Embryos and the Zygotic Embryos of Seed by Cryopreservation and Freeze Drying

Abstract

The value of stored pollen as an efficient way of conserving plant genes in vitro has been widely recognised, as part of a broader strategy for the conservation of plant genetic resources (Towill 1985; Withers and Williams 1986; Alexander and Ganeshan 1988; Withers et al. 1990; Withers 1991). Stored pollen, recovered with acceptable pollination competence, is also of great value in plant breeding and production, as an appropriately compiled inventory of such material removes many difficulties associated with differences in flowering time, season, location and availablility of partners that impair specific plant crosses. The increasing successes of in vitro technology for pollen culture, leading to tissue and plant regeneration, has advantages for industrial and agricultural biotechnology and, consequently, generates a further need for effective pollen storage (e.g. Alexander and Ganeshan 1988; Chen 1990; Tupy et al. 1991). Practical storage procedures, effective for months to several years in different species, have been developed for a wide range of pollens by simple reduction of environmental temperature and humidity, either separately or in combination (King 1965; Towill 1985; Barbosa et al. 1991; Yates et al. 1991; Niimi and Shiokawa 1992; Osborne et al. 1992).