| Lilium sargentiae has a high ornamental and economic value. However, the traditional breeding methods propagation coefficient is low, easily infected cause bulbs degradation and other issues. In production, using tissue culture techniques can greatly improve the propagation coefficient, but plantlets grow weaker, in transplanting process survival rate is low, which has become a prominent problem of factory production lily bulbs.To culture strong seedling and increase the survival rate, we can enlargement bulbs in vitro, and we should not only study the bulbs swollen technology in vitro, more should explain clearly what is swollen mechanism.To this end, we used different concentrations of sucrose(30?60?90?120g/L)to treatment the material, which bulblet scales ofLilium sargentiae as explants to induced sterile buds. To seek optimal concentration of sucrose forLilium sargentiae bulb tube is formed and enlargement, and provide scientific and technical support and practical guidance for the production of high quality. Secondly, we used different of soluble sugars, osmotic potential, sugar analogs and inhibitor to treatment the material, measured the morphological index and endogenous sugar and related enzyme changes in the bulblet enlargement, to explore the signal effect of sucrose on formation and enlargement of bulblet ofLilium sargentiae. The main results of this study are as follows:1. The effect of different concentrations of sucrose on the formation and enlargement of Lilium sargentiae bulb.Compared with the sucrose of 30 g/L(CKi), the sucrose concentration was 60 g/L, the plant have a highest rate of bulblet. At the same time, Sucrose concentration increased from 30 g/L(CKi) to the 60 g/L, the effect of enlargement of bulb continues to grow, which reaching peak in the 60 g/L; with sucrose concentration continues to increase, the effect of enlargement of bulb began to decline. When the sucrose concentration of 90-120 g/L, the effect of enlargement reduced to the level of the control. So the best sucrose concentration was 60 g/L for induce lily bulb formation and enlargement.2. The experiments of osmotic potential whether is involved in process of which we used sugar treatment material.In order to study the exogenous sucrose produce osmotic stress related about whether or not the effect of induced and enlargement of bulb, we used mannitol to treatment material, which the same osmotic potential with sucrose of 60 g/L. The results show that under the same conditions of osmotic potential, the capacity of mannitol induced and enlargement is very low for Lilium sargentiae bulb, and can not generate a new bulb, there are significant differences when compared with the effect of sucrose. Thus, the role of sucrose on formation and enlargement ofLilium sargentiae bulb unrelated with its generated of osmotic stress.3. The effect of different soluble sugar on formation and enlargement ofLilium sargentiae bulb.Sucrose is an important source of carbon and energy source in plant growth and development, in order to investigate the effect of the high concentration of sucrose induced to formation and enlargement of Lilium sargentiae bulb is whether through provide carbon and energy to achieve, We used different of soluble sugars(350.6 mmol/L glucose,350.6 mmol/L fructose; 175.3 mmol/L glucose+175.3 mmol/L of fructose)to deal with the material, which is the same as molecular weight of carbon of 60 g/L sucrose. The results show, in total darkness conditions(TD), the effect of sucrose induced to formation and enlargement of bulb is the best in vitro. Secondly, the effect of fructose and glucose combination process on induce and enlargement of bulb is weak. The affect of separate treatment of glucose and fructose for lily bulbs is more weak, but the difference was not significant. Because sucrose in the structure is made of one molecule glucose and one molecule of fructose composed, and sucrose hydrolyzate is glucose and fructose. Compared with the sucrose, glucose and fructose that have a carbon content the same as sucrose, but the effects of treatment have a significant difference. Therefore, the results show that the sucrose-induced Lilium sargentiae bulb formation and enlargement is highly efficient, and this is not entirely through energy and carbon to achieve.4. The effect of sugar analog on formation and enlargement ofLilium sargentiae bulb.The results showed that we used exogenous 3-OMG to treatment material,which failed to induce the formation and enlargement of bulb; mannitol and isomalt can induce the formation and enlargement of bulb, but their effects of treatment have a significant differences compared with sucrose. The ability of induce and enlargement of bulb from strong to weak are:sucrose> isomaltulose>glucose>mannose> 3-OMG. The role of mannose is by hexokinase phosphorylation, but not further metabolized, it represents the way is hexokinase involved in signal transduction.3-OMG is a poor substrate for hexokinase, and its role is independent of hexokinase signaling pathway. Isomaltulose is a disaccharide, not synthesized in higher plants,but plants cleavage or transport, can not be enzymatic cleavage or transport in plants, and its effect showed that sucrose induced signal level in the cell membrane. Which shows that the role of sucrose on formation and enlargement of bulb relate to signal of sucrose itself.5. The effect of absorption inhibition of sucrose and glucose on formation and enlargement of Lilium sargentiae bulb.The use of reported of study sucrose specific absorption inhibitor(pCMBS)or glucose absorption inhibitor competitive phloridzin interfere with absorption of sucrose or glucose, and found that the exogenous sucrose by the form of transmembrane transport into the intracellular, and a small part is decomposed of cell wall invertase by hexose carrier into the input cells. These two modes of transport for efficient induction of sucrose is required; but the main effect of sucrose on formation and enlargement of lilv bulb is through the sucrose itself to relaize. |
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