Long term in vitro storage of lily: effects of temperature and concentration of nutrients and sucrose

Methods for long-term preservation of lily germplasm were examined. In vitro regenerated bulblets of 10 lily (Lilium L.) genotypes (Asiatic hybrids, Oriental hybrids, L. longiflorum and L. henryi) were stored for 28 months at -2 degrees C and 25 degrees C on four different media: 1/4 or full strength Murashige and Skoog nutrients with 9% (w/v) or 6% sucrose. Sprout growth, bulb growth, and viability were determined. The combination of 1/4 strength MS nutrients and 9% sucrose gave the highest reduction in sprout and bulb growth, the highest viability and the highest percentage of regrowth after 28 months of storage. At 25 degrees C, all lily genotypes survived 28 months of storage under these conditions. At -2 degrees C, Asiatic and Oriental hybrids survived 28 months of storage, whereas genotypes of L. longiflorum and L. henryi survived 6 months of storage, but died during prolonged storage.