Studies On Tissue Culture And Plant Regeneration Of Hosta Ventricosa (Salisb.) Stearn.

The study was mainly to probe an efficient way through tissue culture and rapid propagation of Hosta ventricosa (Salisb.) Stearn. The axillary's bud, inflorescence, embryo and leaves of plantlets were taken as explants. The tissue culture and plant regeneration of Hosta ventricosa (Salisb.) Stearn were systematically studied. The main results as below:The seasons of plant explants from spring to autumn, initiation rates was descended, contamination rates was increasing first and then depressing. The times of get maximum initiation rates were different: axillary's bud and leaves in march, scape and male flower in beginning of may, embryo wasn't restricted in time. contamination rates of plant explants get the Maximum Allowed Value all in august.During the experiment of choice disinfection times, Optimum time was: axillary's bud in 5 min, scape and seeds in 8 rain, male flower and leaves in 3 min.Different treatments on explants were taken during initial culture as follows: The optional culture medium for axillary's bud initiation was MS with 6-BA 1.0 mg/L and NAA 0.1 mg/L. The initial rate was 68.6%. The optional culture medium for male flower initiation was MS with 6-BA 0.5 mg/L and NAA 0.1 mg/L. The initial rate was 84.9%; starting of scape: Callus was induced in MS medium with 6-BA 4.0 mg/L and NAA 0.05 mg/L. The induction rate could up to 48.1%. Induction of callus from leaves and embryo: Callus was induced in MS medium with 6-BA 0.5 mg/L, NAA 0.1 mg/L and 2, 4-D 0.2mg/L. The induction rate could up to 58.2%.Proliferating and differentiating cultivation: The optional proliferating buds culture medium from scape was MS supplemented with 6-BA 0.5 mg/L and NAA 0.5 mg/L, on which it could multiply 7.35 times after 30 d. Highly proliferating callus was obtained from the leaves and embryo following cultivation on MS medium supplemented with 6-BA 4.0 mg/L, 2, 4-D 0.1 mg/L and NAA 0.5 mg/L. The proliferating rates could be up to 87.4%. The best culture medium for callus buds differentiating was MS with 6-BA 1.0 mg/L and NAA 0.5 mg/L. The regeneration rate was 83.0%. Rooting culture: Regenerated shoots could produce roots in 1/2 MS medium containing 2,4-D 0.05 mg/L, NAA 0.1 mg/L and AC0.5%. The rooting rate could up to 83%.Transplanting: Plantlets were transferred to the medium with ratio of 1∶2∶1 of vermiculite and ruby mica and sands. The survival rate was up to 86.7%. During the studies on Tissue Culture of Hosta ventricosa (Salisb.) Stearn, we find that taking the inflorescences as explants, the phases of the callus is very short, as it belong to regeneration way of organogenesis. Comparison of BA and NAA for different ratio under the light or the darkness. The result is showed, taking the male flower as explants cultured in the darkness, could get the highest ratio of the callus; The callus cultured in the darkness can get the highest ratio of the adventitial buds. Overtime the dark treatment, Hosta ventricos plantlet in vitro could come out the node stems with bud. It meaningful for virus-free and germless preservation.Research for growth potential weakened in breeding of plantlet in vitro, that KH₂PO₄, Lacto protein bydrolysate and low-concentration BA reduced the variation of axillary's bud, hold out the growth potential and increasing differentiation.