The Study On Somatic Embryogenesis With Mature Embryo Of Panax Quinquefolium L.and Root Preservation Of Micro-sampling Individuals

In order to provide relevant technical information for American ginseng breeding, the author carried out the following experiment with mature seeds and 2-leaf plants in Liuba County of Shaanxi province: the effects of three kinds of plant growth substances(dicamba, salicylic acid and methyl jasmonate) and liquid culture on somatic embryogenesis of mature seed embryo; the effects of different concentration of 2,4-D on induction of secondary somatic embryogenesis with somatic embryos as explant; comparing the effects of three different treatments(blank, plant ash and ShangKouBao) on the field preservation of 2-leaf plants’ s after micro-sampling on the roots. The main research results are summarized as follows:1. After 40 days’ inoculation of the mature embryo on culture medium supplemented three kinds of plant growth substances(0.05-2mg/L), dicamba of different concentration all can callogenesis and somatic embryogenesis, and the concentration of 1mg/L is the best, the induction rate are 94.3% and 56.6%, respectively; salicylic acid just can induce low level somatic embryogenesis, the range of induction rate was 4%- 7.5%; methyl jasmonate just can induce low level of callogenesis, the highest incidence was 4%. The experimental results show that dicamba promote callogenesis and somatic embryogenesis on American ginseng mature embryo highly, but the effects of salicylic acid and methyl jasmonate was weak.2. The ocurrance rate of secondary somatic embryogenesis on somatic embryo induced by mature seed embryo of American ginseng after 6 months’ inoculation was 58.1% on medium without 2,4-D, on medium with 2,4-D(0.05-2mg/L), the highest ocurrance rate was 28.6%, and the rate decrease with the increase of 2,4-D concentration. The results showed that secondary somatic embryogenesis on somatic embryo occured without hormone, and 2,4-D had inhibitory effect.3. The mature embryos were inoculated in the liquid culture medium supplemented with 2,4-D of 0.5 mg/L and 2mg/L under static and shaking condition. The callus were induced after 30 days, the occurrence rate of static culture was 100%, the occurrence rate of shaking culture was 82.3%, but in two cases, the amount of callus was few, and the volume was small, and there was no somatic embryogenesis. The results showed that the effect of static culture was better than that of shaking culture on callogenesis; liquid culture was not suitable to somatic embryogenesis.4. The roots of 2-leaf plants after sampling were treated in three ways(30 replications for each treatment), and the experiments were carried out in winter and spring. The germination rate of blank treatment was 26.7% and 73.3%, and retaining rates were 40% and 83.3%, respectively. The germination rate of plant ash experiments was 43.3% and 76.7%, and retaining rates were 40% and 83.3%, respectively. The germination rate of ShangKouBao experiments was 43.3% and 76.7%, and retaining rates were 40% and 83.3%, respectively. The datas show that the experiment results of two times were different largely; the treatment effect of plant ash and ShangKouBao were not apparent compared to blank treatment; the difference between germination rate and retaining rate may due to some plant die after emergence, or some do not sproot.