Cryopreservation of test-tube shoot tips of Siraitia grosvenorii by vitrification and plant regeneration / 中草药

ABSTRACT

Objective To get a new approach for conserving the germplasm of Siraitia grosvenorii Methods Shoots, 0.8—1 cm in length, excised from test-tube plantlets which were subcultured 15 d, were precultured. Then its shoot-tips about 2—3 mm in length were dissected and loaded with 60% PVS2 at 25 ℃, and dehydrated with 100% PVS2 at 0 ℃, changed for fresh 100% PVS2 prior to directly plunging into liquid nitrogen. After cryopreservation for 24 h, the shoot tips were thawed, rinsed in MS+1.2 mol/L sucrose medium, blotted with filter papers, then plated on the MS + 1.0 mg/L 6-BA+0.05 mg/L NAA + 0.1 mg/LGA3 + 0.8% agar + 45 g/L sucrose medium at 25 ℃ for 7 d in dark prior to exposure to the light. The root medium for regeneration plantlets was 1/2 MS + 0.2 mg/L NAA + 30 g/L sucrose. Results Shoots were precultured for 3 d on MS + 0.7 mol/L sucrose medium, then its shoot-tips loaded for 40 min, dehydrated for 50 min. After cryopreservation, the shoot tips were rapidly thawed in water at 40 ℃, then rinsed for 40 min. The survival rate of shoot-tips plated on the recovering medium in one week was 100%, and regeneration rate after 30 d was 78.33%, which was the highest. The regeneration plantlets inoculated on root medium were reconstructed integrating plantlets. Conclusion The method of vitrification to cryopreserve the germplasm of S. grosvenorii is a simple way with high survival rate and normal regeneration plants.