[Study on cryopreservation of Pueraria lobata germplasm by vitrification]

The experiment of the cryopreservation technique on Pueraria lobata showed that: At first, the aseptic explants were treated at 4 degrees C for 5 days. Then the stems with buds were cut and precultured at 4 degrees C for 1 day in 5% DMSO + 5% sucrose media. They were dehydrated with 60% and 100% PVS2 (30% glycerol + 15% glycol + 15% dimethyl sulfoxide + 0.4 mol/L sucrose) at 0 degrees C for 30 minutes respectively. At last the stems were immersed immediately into liquid nitrogen directly and conserved for 24 hours. After rapidly thawing in a water bath at 40 degrees C for 90 seconds, the stems were washed two times with MS media supplemented with 1.2 mol/L sucrose and 10 minutes each time, then transferred on the MS media supplemented with BA 2 mg/L and NAA 1 mg/l, in dark for 7 days and then in light. The survival rate was up to 57-58% . The regenerated plant of Pueraria lobata were the same as the normal in morphology.