Effect Of Carbohydrates On The Growth And Biochemistric Properties Of Calli Of Dendrobium Candidum Wall Ex Lindl.

Effect of carbohydrates on the growth and biochemistric properties of embryonic callus of Dendrobium candidum Wall ex Lindl subcultured twice in dark were studied in this paper. The main results were as follows:1. The effects of five carbohydrates (sucrose, frutose, trehalose, maltose and lactose) were studied at different concertration on the calli. The results showed that sucrose, fructose and trehalose were more efficient for the growth of callus, the optimum concertration was 3%, 2%, 3%, respectively; the optimum concertration of maltose and lactose was 2% and 0.5%. The rate of effect of fructose and sucrose was quick, but trehalose was slow; the time of effect of trehalose and fructose was long, but lactose, sucrose and maltose was short. The effect of sugar on the rate of the proliferation of callus almost rose up to a peak at first and then descended, it means that callus grew slowly at lower sugar concentration and the growth of callus was inhibited at higher concentration.2. Three typical carbohydrates (trehalose, sucrose and lactose) were used to assay the content of soluble sugars of calli. The results showed that the content of soluble sugars of calli were increased as the concentration of supplemented sugar increased in vitro, and there was a balance between the concentration of supplemented sugar and the content of soluble sugar, that was 6%, 3%, 0.5%, respectively. The concentration which the content of soluble sugars balanced between in vivo and in vitro were coincident with the optimum concertration of the growth of callus when the calli grow on the medium with sucrose and lactose, but they were not coincident on the medium with trehalose.3. The isoenzymes of calli which grew on the medium with trehalose, sucrose and lactose were studied when the growth velocity was biggest. Beside to the calli grew on the medium with lactose, there were significant differences in the patterns in EST when the calli grew on the medium with sucrose and trehalose, new bands appeared when the concentration was higher, it illustrated that there were new gene expression. The color of the bands was deep at 5% and 9%, respectively, but both light at 3% which the content of soluble sugar balanced between in vivo and in vitro and the optimum concentration of the growth of callus. New bands of SOD appeared at high concentration, the number of bands of SOD decreased as the the culture time increased in three controls. The color of the bands of AMY was deep and the content of soluble sugar was high at high concentration. The color of the bands of AMY was deep in three control, and the color was deeper and content of soluble sugars decreased as the time increased.In conclusion, the sugar which was advantageous for the growth of callus and the optimum concertration were known in this paper. The effect of sugar on the content of soluble sugars of calli was studied. We might conclude that sugar could regulate the expression of gene in the development of the embryonic callus through the analysising of EST, SOD and AMY.