Cryopreservation Of Two Kinds Of Porphyra

Free-living conchocelis of Porphyra yezoensis Ueda 03B and Porphyra haitanensis were cryopreserved in liquid nitrogen using encapsulation-dehydration and encapsulation-vitrification respectively. (一) The cryopreservation of free-living conchocelis of Porphyra yezoensis Ueda 03B by encapsulation-dehydrationIn this part, the conchocelis of P. yezoensis Ueda 03B were encapsulated in 3% Ca-alginate beads. Beads were dehydrated with silica gel, then directly immersed into liquid nitrogen. The main factors influencing the viability, such as dehydration rate, water concent and recovery methods after thawing were studied. The results are as follows:1. Effect of average dehydration rateAt different average dehydration rate (a water reduction per hour 7.5%, 10%, 12.5%, 15%, 20%), conchocelis obtained the highest viability at the dehydration rate of 15% water content/h.2. Effect of water contentAt an average dehydration rate of 15% water content/h, water contents in beads were 10%, 15%, 20%, 25%, 30%, 40%, 50% respectively. The highest viability was obtained when the alginate beads were dehydrated to 15% water content.3. Effect of recovery methods after thawingAfter thawing, the highest viability was obtained when beads of conchocelis of Porphyra yezoensis Ueda 03B were incubated in culture medium for 24h in darkness at room temperature. As to conchocelis of Porphyra yezoensis Ueda 03C, the suitable recovery method was to incubate beads in culture medium for 6h in darkness at room temperature.(二) The cryopreservation of free-living conchocelis of Porphyra haitanensis by encapsulation-vitrificationIn this part, the conchocelis of P. haitanensis were encapsulated in 3% Ca-alginate beads. After loading with 25%PVS, beads were dehydration with 100%PVS, then directly immersed into liquid nitrogen. The main factors influencing the viability, such as exposure time to PVS (Protect Vitrification Solution, PVS) , treatment time of loading solution and washing solution were studied. The results are as follows:...