Studies On Tissue Cuture And Rapid Rropagation Technology Of Chirita Tribracteata

The primary factors which affect on culture were studied during the four stages of chirita Iribracteala tissue culture, which is establishment of bacterial-free culture system, inducting explant differentiation and propagation, stage of root induction and transplantation et. al. The results are shown as below:1. The pedice is the best material in rapid propagation of chirita tribracteatas among the three explants (Pedice with axillary, petal, spire) as it is easy to be induced into adventitious buds. Though, adventitious buds can't be induced from petals and spires; The most suitable time for surface sterilization of explants with 0.1% Hgclz is 7 minutes for pedices and spires, 3 minutes for petal; 0.5-2mg/L 2, 4-D is beneficial to callus formation from petals and spires, but NAA take no effect on callus formation. The rate of inducing callus will be increased with increasing concentration of 2, 4-D.2. The stage of inducing differentiation and propagation.The bud can't be induced from callus, petals and spires of explant with various concentration of BA; The most suitable phytohormone compositions to induce adventitiousbuds from pedices with axillary buds is MS-BA0.5-1.0mg/L-NAA0.1mg/L; Adventitious buds can be induced from leaves of subcultured Plants.The best basis medium for adventitious buds induction and growth is MS; BA can effectively stimulate adventitious formation on test-tube plant leaves, and the optimum concentration of BA is 0.5mg/L, but KT has no action on it. More buds can be induced on the medium with NAA than IBA, but the plants are stronger on the medium added 1BAthan NAA. The buds cultured on medium with IAA are the worst among three media (with NAA, IB A, IAA); 3% of sugar is the best for differentiation and subculture.3. Stage of inducing roots.In the basis media, MS is more beneficial than 1/2MS to roots induction as well as growth. IBA is more effective to root induction than NAA. The most suitable medium for roots induction is MS-IBA0.3mg/L. Roots can be inducted on the medium added 1-4% sugar. However, 2% of sugar is better as stout plantlets are obtained in a low cost.4. Stage of transplantThe survival rate of transplanting is the highest (95%) after plantlets were transplanted in the humus soil. In a year, There are two survial peaks for transplant (March-June and September-November) and two low valleys for transplant (January-February and July-August).5. The factors of causing vitrification and the methods of inhibiting and controlling vitrification.The experiment results showed that the vitrification was mainly caused by higher concentration of BA, lower concentration of sugar and lower salt concentration media. It was also found that vitrification was effectively inhibited by suplemented with PVA (2g/L) and PP333 (2mg/L) and vitrified plant can be reversed into normal plants by supplemented with PVA in the initial vitrification stage. 3g/L PVA is the most effective to conversing vitrification.