| In this paper, the study aimed to find out a new method to improve the quality of rooting of tissue culture seedling of Eucalyptus sp.. So using the tissue culture seedling of Eucalyptus sp., based on the method of orthogonal design and one-time regression orthogonal design, these tests were taken in this study by the photoautotrophic incubator as follow: 1) how the in-vitro micro-rhizosphere factors, including the diameter of sand medium, the concentrations of plant growth regulators and the method of pre-dipping, affect the rooting of the seedling of Eucalyptus sp. , and which formula is the better one by the morphological indexes of rooting, 2) the correlation between the morphological indexes of rooting and the number of root tips, which can gives references about the orientational culture of Eucalyptus sp. during the rooting period of the photoautotrophic micro-propagation , 3) the comparison between the photoautotrophic micropropagation technique and traditional tissue culture, which can show that the micro-propagation technique is more superior than traditional tissue culture. These are the main results as follow:1) The diameter of sand medium affects the rooting of photoautotrophic micropropagation differently, and has very significant influence on the rooting rate and the rooting activity(p<0.01). Among 4 diameters for tests, the class of 0.5～1.0 mm behaves best in the rooting rate(66.67%) and the rooting activity(118.94μg/(g·h)), which is higher than the non-selected one by 25.014% and 14.201%.2) In the ex-vitro microenvironment condition of G1(light intensity of 9000 lux,CO2 concentration of 1200 ppm, temperature of 22℃, relative humidity of 75%, photoperiod of 17 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G1A1 (clear water), G1A2 (NAA 2.0 mg/L + VB12 10 mg/L), are better than other ones. The G1A1 formula can makes many root tips, big root surface area, long root length and great root volume, and the G1A2 formula can makes many root underground biomass and high rooting rate.3) In the ex-vitro microenvironment condition of G2(light intensity of 3000 lux,CO2 concentration of 1200 ppm, temperature of 27℃, relative humidity of 95%, photoperiod of 12 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G2A1 (NAA 2.0 mg/L + pre-dipping time of 2 seconds), G2A2 (NAA 2.0 mg/L + VB12 10 mg/L), and G2A3 (NAA 2.0 mg/L + VB12 10 mg/L + pre-dipping time of 2 seconds), are better than other ones. The G2A1 formula can makes many root tips, big root surface area and long root length, the G2A2 formula can makes many root underground biomass and high rooting rate, while G2A3 can makes big root volume.4) In the ex-vitro microenvironment condition of G3(light intensity of 9000 lux,CO2 concentration of 1200 ppm, temperature of 27℃, relative humidity of 75%, photoperiod of 12 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G3A1 (clear water), G3A2 (NAA 2.0 mg/L + VB12 10 mg/L), G3A3 (IBA 3.0 mg/L + NAA 3.0 mg/L + VB12 20 mg/L + pre-dipping time of 2 seconds), and G3A4 (IBA 3.0 mg/L + NAA 3.0 mg/L + VB12 10 mg/L + sucrose 2% + pre-dipping time of 2 seconds), are better than other ones. The G3A1 formula can makes many root tips, big root surface area and great root volume, the G3A2 formula can makes long root length, and the G3A3 formula can makes high rooting rate, while G3A4 can makes many root underground biomass.5) In the ex-vitro microenvironment condition of G4(light intensity of 9000 lux,CO2 concentration of 450 ppm, temperature of 22℃, relative humidity of 95%, photoperiod of 12 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G4A1 (1/4 MS), G4A2 (sucrose 2%), G4A3 (IBA 3.0 mg/L + NAA 2.0 mg/L + pre-dipping time of 2 seconds), and G4A4 (clear water), are better than other ones. The G4A1 formula can makes many root tips, the G4A2 formula can makes long root length, and the G4A3 formula can makes high rooting rate, while G4A4 can makes big root surface area and many root underground biomass.6) In the ex-vitro microenvironment condition of G5(light intensity of 9000 lux,CO2 concentration of 450 ppm, temperature of 27℃, relative humidity of 95%, photoperiod of 17 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G5A1 (IBA 3.0 mg/L + pre-dipping time of 2 hours), G5A2 (IBA 3.0 mg/L + NAA 2.0 mg/L + VB12 20 mg/L + pre-dipping time of 5 hours), G5A3 (IBA 3.0 mg/L + NAA 2.0 mg/L + sucrose 2% +1/2 MS + pre-dipping time of 5 hours), and G5A4 (pre-dipping time of 5 hours), are better than other ones. The G5A1 formula can makes high rooting rate and great root volume, and the G5A2 formula can makes many root underground biomass, and the G5A3 formula can makes long root length and big root surface area, while G5A4 can makes many root tips.7) In the ex-vitro microenvironment condition of G6(light intensity of 3000 lux,CO2 concentration of 450 ppm, temperature of 22℃, relative humidity of 75%, photoperiod of 12 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G6A1 (IBA 3.0 mg/L + NAA 2.0 mg/L), G6A2 (IBA 3.0 mg/L), G6A3 (clear water), G6A4 (IBA 3.0 mg/L + NAA 2.0 mg/L + sucrose 2%) and G6A5 (IBA 3.0 mg/L + VB12 20 mg/L), are better than other ones. The G6A1 formula can makes many root tips, the G6A2 formula can makes long root length, the G6A3 formula can makes many root underground biomass, and the G6A4 can makes high rooting rate, while the G6A5 can makes great root volume and big root surface area.8) In the ex-vitro microenvironment condition of G7(light intensity of 3000 lux,CO2 concentration of 1200 ppm, temperature of 22℃, relative humidity of 95%, photoperiod of 17 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G7A1 (VB12 20 mg/L), G7A2 (VB12 20 mg/L + sucrose 2%) and G7A3 (clear water), are better than other ones. The G7A1 formula can makes many root tips and long root length, and the G7A2 formula can makes high rooting rate, while the G7A3 formula can makes big root surface area, great root volume and many root underground biomass.9) In the ex-vitro microenvironment condition of G8(light intensity of 3000 lux,CO2 concentration of 450 ppm, temperature of 27℃, relative humidity of 75%, photoperiod of 17 h/d), the primary photoautotrophic propagation formulas for the rooting of seedling of Eucalyptus sp., G8A1 (clear water), G8A2 (IBA 1.5 mg/L + NAA 2.0 mg/L + 1/2 MS + sucrose 2%) and G8A3 (IBA 1.5 mg/L + NAA 4.0 mg/L + sucrose 2%), are better than other ones. The G8A1 formula can makes many root tips, long root length, big root surface area and great root volume, and the G8A2 formula can makes many root underground biomass , while the G8A3 can makes high rooting rate.10) The results about correlation between the photoautotrophic micropropagation indexes for the rooting of seedling of Eucalyptus sp. and the root tips number indicates that the correlation between root length and root tips takes NO.1 position in the micro-environmental condition of G1, G3, G4, G6, G7, G8. In different ex-vitro micro-environmental conditions, the correlation order between the rooting indexes and root tips behaves some differences. In the micro-environmental condition of G1 and G2, the orders are same, behaves as follow: root length>root surface area>root volume>root underground biomass>rooting rate. And in the micro-environmental condition of G3 and G4, the orders which is root length>rooting rate>root underground biomass>root surface area>root volume are also same.11) Different ex-vitro microenvironment conditions has very significant influence on the rooting rate and the rooting activity(p<0.01). the condition of G1(light intensity of 9000 lux,CO2 concentration of 1200 ppm, temperature of 22℃, relative humidity of 75%, photoperiod of 17 h/d), which is the best ex-vitro microenvironment condition.12) Compared to traditional tissue culture, the photoautotrophic micro-propagation technique takes obvious advantage at increasing root length, root surface area and root volume. The tests results shows that in the ex-vitro micro-environmental condition of G3(light intensity of 9000 lux,CO2 concentration of 1200 ppm, temperature of 27℃, relative humidity of 75%, photoperiod of 12 h/d), after 25 days propagation, the indexes of No.18 treatment including rooting rate, root underground biomass, root length, root surface area and root volume, are higher than the traditional tissue culture with sucrose by 7.143%, 14.715%, 182.638%, 718.289%, 2559.459% and 36.793%, and are higher than the traditional tissue culture without sucrose by 133.334%, 2456.767%, 642.678%, 2380.907%, 10150.000% and 310.613%. |
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