| S.grosvenorii is an important economic plain grown in Guangxi locally. Its fruit can be used as Chinese traditional medicine directly. There are plentiful fructose, glucose, protein and variety of vitamin in its fruit. The fruit has been used as a folk medicine for sore throats, cough, minor stomach and other troubles. Now, it has been used for drinking and condiment. The sweet triterpenoid glycosides in its fruits may serve as a sweet substance for those who suffered from diabetes, adiposity and hypertension.Nowadays, S.grosvenorii is facing problems of varietals scarcity, degeneration and hybridization. Above 70% seedling is male and it is difficultly distinguished. So, sexual multiplication of S.grosvenorii is restricted. And the methods of grafting, stem cutting or layer has low propagative coefficient and they easily result in degeneration of good species. Tissue culture technique is an effective way of rapid propagation and it can maintain the good character. In order to establish an effective system for the rapid propagation, the stem cuttings of S.gosvenorii were used as explants in vitro culture to induce the plant regeneration. In order to select the appropriate explants and time of sterilization, all kinds of explants were cultured on MS medium supplemented with different sugar and hormone concentration and proportion. The induction and growth of buds were studied. The shoots were cultured on MS medium supplemented with different salt and sugar concentration and were treated with different days of dark and temperature. The capability of forming tuber was investigated. Stem cutting, rooting, transplanting were experimented. After planted out, the growth of plantlets was observed. The flowering phase and fruit character and the growth of tuber were investigated. Sweet triterpenoid glycosides (mogroside) were measured.It was found that the sprouts cut during April and May, and the middle and above cuttings of same sprouts are optimal explants. The most optimal method of surface sterilization is dipped in 70% alcohol for several second and then in 0.1%Hgcl2 about 10 min.The highest induced rate of buds could be obtained during April and May, or fromSeptember to November. The results showed that: (1) 1.5%sucrose combined with 1.5% glucose is in favor of the buds growth; (2) 6-BA favored the differentiation of buds. (3) 6-BA (0.5mg/L) combined with NAA (0.05mg/L) is favorable not only for the differentiation but also for the lengthening growth of buds. When sprouts were subcultured on medium supplemented with 6-BA (0.5mg/L) and NAA (0.05mg/L), their propagation coefficient was 4.5. The shoots were cultivated plantlets easily after inoculated in IBA (0.1mg/L) medium.The results showed when supplemented with salt concentration of 1/4MS, 6% sucrose, treated with 15- 30- days dark, incubated at 15- 20℃, the apical buds were in favor of the tubers formation and growth.The cutting results showed that the best period was May and June. The optimal hormone concentration combination was NAA 1.0mg/ml + IBA 1.0mg/ml. In these conditions, the survival percent was the highest.The time climbing the shelf and flowering phase of tube plants was later than that of traditional plants. However, the tube plants grew fast in mid-late period than traditional plants. The one-year-old tubers of tube plant were big and short. Compared with traditional plants , tube plants had higher yield, their flowering rate was 68.7% in the first year, the highest amount of fruits was 282, and the average amount of fruits was above 100, which obviously higher than that of traditional plants, the content of mogroside Ⅴ in fruits increased by 39.78% to 126.68%.
|
PDF Full Text Request