| Summary: | 碩士 === 國立嘉義大學 === 園藝學系研究所 === 100 === In this study, shoot tip of the sweet potato ( Impomoea batatas (L) Lam. ) cultivars Tainung No. 57, No. 66, No. 71 and No. 73 were used for the materials of the following four trials : (1)the effect of different time of Loading Solution ( LS ), Plant vitrification solution 2 ( PVS2 ) and plant vitrification solution 3 ( PVS3 ) on the survival rate of shoot tips of sweet potato after cryopreservation. ( 2 ) Effect of different types and concentrations of plant growth regulator on plant regeneration of sweet potato callus after cryopreservation. ( 3 ) Assessment on application and potential of Aluminium cryo-plates technology in cryopreservation. ( 4 ) Comparison with agronomic traits of regenerated plants with and without cryopreservation. shoot tips of four sweet potato cultivars after encapsulation were pre-cultured in liquid Murashige-Skoog medium with 30 g/l sucrose for 24 hr., then cultured in liquid MS medium with 0.3 M sucrose for 16 hr.. Shoot tips of four sweet potato cultivars were osmoprotected with LS for 0, 60, 120, 180, 240, 300 and 360 min., and dehydrated with PVS2 or PVS3 for 1 hr.. Then immersion directly into liquid nitrogen for 1 hr. shoot tips were rapidly warmed and placed on the recovery medium for 30 days in order to measure survival rate of shoot tips. The results had shown that Shoot tips were osmoprotected with LS for 300 min., and then dehydrated with PVS2 for 1 hr., had highest rate of callus formation rate for sweet potato cultivars Tainung No. 57, No. 66, No. 71 and No. 73, were 86.7 %, 93.3 %, 96.7 % and 83.3 % respectively. And the plant regeneration rate were 3.3%, 3.3%, 3.3% and 3.3% respectively. About plant regeneration of callus from shoot tip in all treatments after cryopreservation, only the BA + Kinetin treatment in the sweet potato cultivar Tainung No. 73 had root differentiation and differentiation rate was 7 %. Comparison with the encapsulation vitrification method and aluminium cryo-plates technology in cryopreservation, aluminium cryo-plates technology could reduce 45% of the processing time and reduce 70% of drugs. plant regeneration rate of sweet potato cultivars Tainung No. 66 and No. 71 were 3.3% respectively. In the comparison with the agronomic traits, plants after cryopreservation in sweet potato cultivars Tainung 66, 71 and 73 had the same plant characteristics as the plants without cryopreservation. Whether cryopreservation may cause genetic variation or virus –free of sweet potato or not needs more researches to confirm .
Key worlds：Sweet potato, cryopreservation, Loading solution ( LS ), Plant vitrification solution 2 ( PVS2 ), Plant vitrification solution 3 ( PVS3 ).
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