Studies On Technique Of Tissue Culture And Cuttage Propagation Of Cerasus Subhirtella Var. Ascendens

Cerasus subhirtella var. ascendens subordinates the genus of Cerasus, Rosaceae. The color of flower is pale pink as a tall deciduous tree.Cerasus subhirtella var. ascendens has advantages of high ornamental value, flexibility, strong resistance. It is one of wild cerasus resources with extremely high value. The thesis launched cuttage and tissue culture technique of Cerasus subh- irtella var. ascendens , so as to find the effective way of improving the quantity and quality of Cerasus subhirtella var. ascendens and providing theorical and technical support for production and germplasm conservation.Used soft cuttage method, the thesis studied the promotion of different cutting substrates, plant growth regulators etc in cutting rooting of soft wood. The main conculusions were drawn as follows:Rooting rate was 78.2% for solf cutting of half wooded stem treated with 1000mg/L NAA, 500mg/L IBA and 100mg/L BA for 30 minute on the substrate with vermiculite. The average number of root could reach 7, and the average length of root was 5.6 centimeter. Based on the above technology, the rooting rate of Cerasus subhirtella var. ascendens could reach 78.2%, Survival rate of transplating reached 50%.The research results further improved cuttage reproduction technical system, and had high practical value in the production.Used tissue culture technology, this thesis studied the whole protocol of tissue culture from the establishment of germfree system, initiation culture, proliferation and strengthening seedling culture to the radication and transplantation. The conculusion was made as follows:1 Taking the stem with axillary bud as explant, the best way of sterilization was 70% alcohol(30s)+ 2.5% NaClO(15min)+0.1% HgC12(6min), the contaminated rate and death rate were lowest, which were 16.5% and 10.4% respectively after inoculatation. The best time of extraction is the middle ten-day of April.2 Used the L934 orthogonal experiment design on the initiation culture, the greatest effect was medium type, secondly it was cytokinin concentraton, the smallest effect was NAA. The optimum medium was MS+BA1.2mg/L+NAA0.3mg/L for initiation induction.The initiation rate was 84.5%.3 On the proliferative growth stage, the optimun medium for bud proliferation was MS+BA0.5mg/L+NAA0.1mg/L+sucrose35g/L. Proliferation coefficient was 4.5. Paclobutrazol of Suitable concentration(1mg/L) played promoting proliferation and inhibiting height roles. For the sake of keeping proliferation coefficient,subculture to six times was suitable.4 Used the L934 orthogonal experiment design on strengthening seedling culture, the greatest effect was mass element of propotion, secondly it was NAA, the smallest effect was BA. The optimum medium for strengthening seedling culture was 3/4MS+BA0.2mg/L + NAA0.01mg/L. Both adequate mass element and the low level of cytokinin and auxin proportion were in favor of strengthening seedling culture.5 The optimum medium was 1/2MS+NAA0.1mg/L+IBA 1.0mg/L for rooting,the rooting rate could reach 92.5%, the root number could reach 8, the root length could reach 6.3 cm. Fourteen days dark treatment promoted rooting of vitro seedling.6 Selected heathy vitro seedlings, closing the culture bottle for 3 days, then opening the culture bottle for 5days during seedling training. Substrate with vermiculite and sand by 1 to 1 was the optimum. The suvival rate of transplants reached 90%.Experimental indexes have reached the requirement of rapid propagation seedling, the technical measures could meet production needs.