Study On Rapid Propagation Of Energy Plant Euphorbia Tirucalli

Euphorbia tirucalli is one kind of potential energy plants. It belongs to a multipurpose plant and it is worthy to develop its value. Therefore, it is very important to establish the rapid propagation of Euphorbia tirucalli. This study researched on two different ways of propagation of Euphorbia tirucalli, including tissue culture and cuttage. The conclutions were as follows:1.In terms of tissue culture propagation:The optimum time to collect the material was in the sunny afternoon between 14:00 and 15: 00 in November. The best parts of the material were one-year stem segments with axillary bud. The optimal sterilization processing of experimental material was washed by running water for 0.5 h, then preprocessed them with 5% Xiaojiajing disinfection solution for 1 min, then washed these stem segments with 75% ethanol for 30 s and treated by 0.1% mercuric chloride(HgCl2) and one drop Tween-80 for 10 min. As a result, the contamination rate and mortality rate were low and the survival rate was 86.67%.This treatment caused little injury to explants which contributed to germination. The optimum induction culture medium of germination culture was 1/2MS+NAA 0.02 mg/L+6-BA 1.0 mg/L, with differentiation rate of 89.7%; the best multiplication culture medium was 1/2MS+NAA 0.02 mg/L+6-BA 0.6 mg/L+AD 3.0 mg/L, and the test-tube plantlet grew fast and with more effective buds, the multiplication coefficient was 5.70; the optimum rooting culture medium was 1/2MS+NAA 0.4 mg/L+IBA 0.4 mg/L, with many long taproots and fibrous roots and transplanting survival rate of 80%.2.With the length of about 20 cm branches of Euphorbia tirucalli as the material in the research , cuttaging them in field. This paper chose the density of cuttages, fertilizer, combined hormone as the investigation factors, based on the orthogonal L9 (34) array to design the experiment. Referring to morphological characters including plant height growth rate, main stem diameter growth rate, main stem superficial area growth rate, and main stem volume growth rate; physiological indicators including such as photosynthetic rate, stomatal conductance , intercellular CO2 concentration and transpiration rate. Biomass indicators contain plant weight growth rate, total fresh weight with root system, fresh weight of aboveground part, fresh weight of branches; finally selected the best propagation combination(A3B2C1).That was to say ,the 250,000 plants/ha of the Cuttage-density, 300 kg/ha of the fertilizer, and 1.5 mg /ha of the combined hormone. The study showed that 300 kg/ha of the fertilizer, and 1.5 mg /ha of the combined hormone was the climax among the three levels. If the cuttage-density increased to some extent based on the 250,000 plants/ha, maybe in favor of improving the propagation rate.3.Tender branches rooting: with 250 mg/L, 500 mg /L of NAA and IBA soaked 4-5 cm and 6-7 cm of the twig morphology of the end of the articles for 5 min. After cuttaging, covered film in the nursery. And 30 d later, counted the rooting number of the shorter length of tender branches, the results showed that the length of 6-7 cm branches which dealt with the concentration of 500 mg/L of IBA immersed for 5 min, rooting effect was better and grew faster, while the length of 4-5 cm of the branches were largely dependent on plant growth regulators'induction. With 500 mg/L of IBA immersed for 5 min, the best rate of rooting was 90%; on the same conditions, 500 mg/L of NAA soaked for 5 min, rooting rate was lower.4.The effect of Euphorbia tirucalli special fertilizer: The special fertilizer and special liquid fertilizer which we specially used for Euphorbia tirucalli, could greatly promote the growth of Euphorbia tirucalli. The effect was better than singly used the compound fertilizer, urea, calcium magnesium phosphate fertilizer, potassium chloride, etc, and it reduced the angle between branch and main stem by 13.4°- 15.5°, cuttage density can be increased to improve the biological yield.5.Under present conditions, although the production of regenerating through tissue culture and transplanting was successful, the tissue culture propagation techniques of Euphorbia tirucalli still in its infancy. Euphorbia tirucalli test-tube plantlet grew slowly, breeding cycle was too long, and the survival rate of transplanted plantlets was low, so factory production technology still needs further research. Cuttage propagation was more mature than tissue culture, for cuttage material large, with high-growth start and fast growth, coupled with application of our self-developed special fertilizer and special liquid fertilizer of Euphorbia tirucalli, which not only significantly promoted shoot growth and bud differentiation, but also reduced the angle between branch and main stem. Because of compact plant type, the cuttage density can be increased, so that biological yield and breeding speed can be improved, and it also lay the solid foundation for optimizing the cuttage propagation programs.