A Preliminary Study On Tissue Culture And Cryopreservation Of Stone Garlic (Lycoris Spp.)

Stone garlic (Lycoris spp.), which is both an important ornamental and native medicinal plant in China, now confronts the danger of germplasm damage. To solve this problem, tissue culture is an efficient way not only for fast propagation, but also for breeding and genetic resource conservation ( cryopreservation).In order to ensure the safe and long-term conservation of stone garlic (Lycoris spp.), cryopreservation, i.e. storage at ultra-low temperatures (-196 °C), is a good choice for conservation of genetic resources of plant species which are vegetatively propagated. Among these cryopreservation methods, vitrification is an easy, efficient and widely used procedure.Tissue culture of Lycoris spp.Induction of good bulblets for different uses was studied by culturing scales on MS medium with different 6-BA and NAA combinations. The result showed that the scales on MS+BA3mg/L+NAA1.5mg/l had the highest induction rate of 53% with healthy and uniform bulblets for cryopreservation. The optical medium to propagate bulblets in vitro was MS+ BA 1mg/L+NAA 0.5mg/l.As for meristem induction, three types of callus were induced in MS medium with different combination of 2,4-D and NAA. Among them, Somatic embryogenesis was observed on MS+2,4-D 2mg/L+BA0.5 mg/L and MS+NAA 3mg/L+6-BA 3mg/L, and the somatic embryos further developed into plantlets.Bulblets inducted from other six species of Lycoris spp. were also investigated. Bulblets could be induced from five of the six species.Cryopreservation technology of in vitro shoot-tips of Lycoris radiata L. by virtrificationAn efficient cryopreservation procedure by vitrification was developed for long-term conservation of in vitro shoot tips of Lycoris radiata. The procedure includes 4 steps: A. The 2-3 mm length in vitro-grown shoot tips were precultured on MS medium enriched with 0.4 -0.5 mol/L sucrose for 3-4 d; B. Sucrose precultured shoot tips were treated for 20 min with a loading solution (LS) containing 2 mol/L glycerol and 0.4 mol/L sucrose at 25℃; C. Then they were subjected to ice-cooled PVS2 solution for 80 min, transferred to 2 ml cryotubes and plunged into liquid nitrogen. D. Rapid thawing took place in 40℃ water bath for 2 min followed by the deloading step for 20 min in a deloading solution consisted of 1.2 M sucrose liquid MS medium. Further recovery and growth happened on...