Simplified cryopreservation of sweet potato [ Ipomoea batatas (L.) Lam.] by optimizing conditions for osmoprotection.
Shoot tips of sweet potato were successfully cryopreserved using an encapsulation vitrification method. Encapsulated shoot tips were pre-incubated in liquid Murashige-Skoog medium containing 30 g/l sucrose for 24 h, then precultured in sucrose-enriched medium (0.3 M sucrose) for 16 h. Shoot tips were osmoprotected with a mixture of 2 M glycerol and 1.6 M sucrose for 3 h before being dehydrated with a highly concentrated vitrification solution (PVS2) for 1 h at 25 degrees C. The encapsulated and dehydrated shoot tips were transferred to a 2 ml cryotube, suspended in 0.5 ml PVS2, and plunged directly into liquid nitrogen. Rapidly warmed shoot tips developed normal shoots and roots in 21 days without any morphological abnormalities after plating on a recovery medium. High levels (average of about 80%) of shoot formation were obtained for three cultivars of sweet potato. This encapsulation vitrification method appears promising for cryopreservation of sweet potato germplasm.
Hirai
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Hokkaido Central Agricultural Experiment Station, 069-1353 Naganuma, Hokkaido, Japan. hiraidai@agri.pref.hokkaido.jp
Sakai
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A
D015925:Cryopreservation / Q000379:methods*; D003470:Culture Media / Q000737:chemistry; D003890:Desiccation; D005990:Glycerol / Q000737:chemistry; D027723:Ipomoea batatas / Q000254:growth & development* / Q000502:physiology*; D009994:Osmolar Concentration; D018520:Plant Shoots / Q000254:growth & development* / Q000502:physiology*; D012098:Reproduction; D013395:Sucrose / Q000737:chemistry; D013997:Time Factors
D003470:Culture Media; D013395:Sucrose; D005990:Glycerol