Study On The Rapid Propagation Technology Of Panax Quinquefolium

In this study, the experimental materials are the seeds of Panax quinquefolium which isfrom the Standardized Demonstration Zone of Liuba, Shanxi Province. It researches theeffection of Callus induction and Embryoids in different explants, the growth regulatorsubstances and the culture conditions which is on the basis of MS as a basic medium.Through the germination of embryoids which can obtain the regenerated plants, it caninitially establish the technology system of rapid propagation of Panax quinquefolium. Inaddition, the study also observes the process of somatic embryogenesis by using of theparaffin section method.The innovations of the study: The systematic study on the different concentrations of2,4-D which has the effections of callus induction and somatic embryogenesis by differentphysiological status of the embryo （immature, mature, sprouting）, different parts （cotyledon,hypocotyl, petiole, leaf） from sterile seedlings of different culture time; It also study on theinfluence of mature zygotic embryo germination seeds by different concentrations of GA₃.The major findings are summarized as follows:1. A variety of materials were not formated the callus and embryoids with the mediumnot add2,4-D, it shows that auxin is the essential factor in inducing embryoid of Panaxquinquefolium in vitro culture. Histological observation showed that most of the embryogeniccallus were originated on the surface or close to the surface of cells; On a piece of callus canbe observed the different developmental stages of globular, heart-shaped, torpedo-shaped ofembryoids.2. The callus induction rate of mature and sprouting embryo can up to100%with thedifferent concentrations（0.5,1.0,2.0,4.0mg l-1） of2,4-D, embryogenesis rate were decreasedwith the concentration of2,4-D increased; Callus induction rate of immature embryo wereincreased with the concentration of2,4-D increased, but not observed the somaticembryogenesis, it shows that the significant differences in somatic embryogenesis ofimmature, mature and sprouting embryo; The difference was not significant between mature cotyledons and complete mature embryo.3. Most embryos grows slowly and can not germinated into seedlings with the mediumwhich was not added hormones, the double–stem seedlin with dormant buds germinate in thejunction of the cotyledon and hypocotyl can be formated with1/5explants which wascultured with the medium of10mg·l^-1and15mg·l^-1GA₃. The effect of differentconcentrations of2,4-D with different parts（cotyledons, hypocotyls, petioles, leaves） of thedifferent culture time （4weeks,6weeks,8weeks） of sterile seedlings shows, callus inductionrate can up to100%by high concentrations of2,4-D; But the somatic embryogenesis withvarious materials can be inhibited by high concentrations of2,4-D, especially the sterileseedling which is cultureed in a long time, embryoids of cotyledon have a higher incidencecompared to the hypocotyl, petiole and leaves.4. Somatic embryogenesis can be induced by IAA, NAA and2,4-D; The induction withthree auxin is IAA> NAA>2,4-D, the rate can up to90-100%by5²0mg·l-1IAA, the ratecan up to96.55%by the optimum concentration of2mg·l-1NAA, the rate can up to81.81%by0.5mg·l^-12,4-D.5. The normal regenerated plants can be formated from the embryos by GA₃.