| Eucalyptus grew in Australia at first. It belongs to myrtle family, which is an ever-green and fast-growing arbor with broad-leaves. It is both one of the three fast-growing species and an excellent raw economical plant for forestry, which is mainly used for industrial pulp, artificial board and refining eucalyptus oil. Owing to the fact that tropical zone is the origin of eucalyptus, low temperature has become a bottleneck for cultivating eucalyptus on the mid-tropical zone and even further north. Eucalyptus camalolulensis and Eucalyptus dunnit are excellent cold-tolerant plants being cultivated in Hunan province, but Eucalyptus camalolulensis varies in seed quality, and Eucalyptus dunnit has difficulties in sexual propagation. Therefore, the way has a significant meaning that local cold-tolerant plants were chosen on the areas of mid-Subtropical zone and modern biological technologies were adopted to do isolated generative propagation.This article has a primary study on the isolated culture and regeneration of partial excellent branches of Eucalyptus camallulensis and Eucalyptus dunnit, and meanwhile has studied and optimized the conditions of adventitious bud proliferation and radication transplant.1 the study on the best culture medium of bud inducementThe results show that the best medium for Eucalyptus camallulensis is MS+6-BA0.5mg/l+NAA0.2mg/l+Vc0.3mg/l. The highest inductivity can reach 72%. For E. dunnii it is MS+6-BA2.0mg/l+NAA0.2mg/l+Vc3mg/l. The highest inductivity can reach 66%. There are some differences in different sections of buds. The inductivity on Section 1 to 3 from top is 40% higher than that on section 4 to 6.2 the study on the impact of plant growth regulating substance, hydrolyzed casein, gibberellins, PH and water quality on ramification proliferationThe results show that during the process of proliferic culture, growth regulating substance plays a dominant role. The best medium group for swamp gum is MS+6-BA0.5mg/l+IBA0.2mg/l+NAA0.1mg/l. It is 6-BA0.5mg/l +IBA0.2mg/l +NAA0.2 mg/l for E. dunnii. There is little difference in increased weight of buds among different varieties, but in maximum proliferic times. The figure of times forEucalyptus camallulensis 3 is 5.43, 7.65 for Eucalyptus camallulensis 100 and 7.9 for E.dunnit. Hydrolyzed casein has obvious effect on adventitious bud propagation. Hydrolyzed casein of 400 ppm of concentration has bigger effect than that of 100 ppm, 200 ppm, or 500 ppm. The increased weight of buds is 14.53 for Eucalyptus camallulensis 3 and it is 23.32 for Eucalyptus camallulensis 100. The extreme deviation can reach 2.4 and 14.26 respectively. The times of propagation can reach 5.9 and 9.6 respectively. The extreme deviation for the times of propagation can reach 2.0 and 2.6 respectively; pH has obvious effect on proliferation and root growth. Eucalyptus camallulensis 3, Eucalyptus camallulensis 100 and E. dunnii have the maximum coefficients in the region of pH 6.0. The maximum coefficients are 4.8, 7.34 and 7.3 respectively. Compared with the environment of pH 5.4 (the lowest), the extreme deviations can reach 1.7, 2.54 and 3.6 respectively. As far as radication percentage is concerned, it is 90% and 100% respectively for Eucalyptus camallulensis 3 and Eucalyptus camallulensis 100. The corresponding extreme deviation can reach 40% and 27% respectively. Provided that purified water, distilled water and tap water are used to proportion premium, no difference in propagation between purified water and distilled water is found. It is also found that tap water had bad effect on bud propagation and had a propagation rate of 1.5 times less than that in purified water and distilled water in average. Gibberellins have a certain effect on adventitious bud growth. The higher the concentration is, the bigger the stretching extent of buds' leaves is, but it makes against radication. Under 0.5mg/L of concentration, the radication rate is only 25%. The percentage of dry weight is 0.8% lower than that in normal propagation. 3 study on good seedlings cultureThe results show that regulating hormone can do good to seedling. Appropriate culture premium is MS+IBA0.2mg/l+NAA0.1mg/l. Good seedling culture premium and propagation culture premium can be used interchangeably to improve buds' quality. The coefficient of buds' propagation is 1.6 times higher than that of normal propagation. The radiating light of the sun is better than fluorescent lights in good seedling culture. The coefficient of propagation increases by 1.9 times. The bottle seedling after acclimatization can be used for propagation and has obvious effect ofgood seedling. Thus, the coefficient of propagation increases by 1.8 times. The main stalk increases by 0.4mm, the thickness of stalk increases by 0.03mm. The percentage of buds' dry weight after doing good seedling is 6% higher than that of normal ones.4 study on the best culture premium for regenerative seedlingsThe results show that 1/2 MS+IBA0.5mg/l+NAA (0.1mg/l~0.3mg/l) is ideal for the radication culture premium of Eucalyptus camallulensis. By contrast, E. dunnii has more difficulties in radication. After primary filtration, E. dunnii, under the condition of 1/4 MS+IAA0.5mg/l+NAA (0.1mg/l~0.5mg/l), has little radication which is less than 20%.5 Study on the relevant factors of transplant of regenerative seedlingsThe results show that the survival rate of bottle seedlings has something to do with days of acclimatization, ground substance and season. 10-15 days of acclimatization are even better. The radication rate can reach98%. The extreme deviation is 15%. The ground substance containing 30% of peat soil and 70% of yellow soil makes for mature seedling. From April to June and from September to October are ideal periods for transplant and the survival rate can reach 95.3%.
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