Study On The Rapid Propagation And Regeneration Of Bletilla Striata Seedlings

Bletilla striata is one of the endangered traditional Chinese medicinal herbs, which is artificially cultivated with plant division by high cost and risk. Now with the application of tissue culture technique the propagation coefficient, could be improved as much as possible.In this experiment, the different levels and combinations of PGRs, were used to study the effects on seed germination stimulation, callus induction, proliferation,differentiation, subculture and rooting induction of Bletilla striata seeds in order to obtain the optimized tissue culture system for the purpose of providing technical support for batch cultivation of Bletilla striata seedlings. The main results were as follows:1. The seeds of Bletilla striata were very tiny which born without endosperm., and some of them even had no embryo. In this situation, it’s far more difficult to germinate in natural environment for seeds. The best medium for germination was 1/2MS+3%Sugar+0.6% Agar+1.0 mg/L NAA, which gained the germination rate of 88.66% with higher speed and better growth of protocorm.2. The optimal medium for callus induction was MS+3% Sugar+0.6% Agar+2.0mg/L 2,4-D+1.0 mg/L NAA+1.0 mg/L 6-BA with the induction rate of 88.67%. And the callus had firm texture and green appearance which could be rapidly induced in differentiation.3. The optimal medium for callus proliferation was MS+3% Sugar+0.6% Agar+3.0mg/L 2,4-D+1.0 mg/L 6-BA, the proliferation coefficient was 1.80. In addition, the effect of 2,4-D was significant. The callus began to differentiate instead of proliferation without2,4-D.4. The best medium for callus differentiation was MS+3% Sugar+0.6% Agar+0.5mg/L TDZ+1.0 mg/L 6-BA, which gained the differentiation rate of 98.33%. Besides, the differentiation effect of these callus was quite notable which was induced by mostly6-BA and TDZ played a prominent role in the differentiation of callus.5. The best medium for inducing adventitious-bud was MS+3% Sugar+0.6%Agar+2.0 mg/L KT+1.0 mg/L NAA, the proliferation coefficient was 2.71 and the average height of seedling was 3.3cm under the cultivation.6. The optimal medium for inducing adventitious-roots was 1/2MS+3%Sugar+0.6% Agar+1.0 mg/L NAA+7.5% Banana juice, the average amount and the length of roots was 4.6 and 3.14 cm respectively under the condition.