| The present study analysis and explored the rapid propagation technique system of explant induction, subculture, root induction and transplanting for 3 clones of Eucalyptus urophylla x E. grandis (DH32-26, DH32-28, DH32-29) which as testing materials of the tissue culture and rapid propagation research. Major results were as follows:1. This research concluded the optimal season for the explant induction and clarified the effects of different parts and different disinfection duration of the explant sampling on the induction rate of those 3 clones of Eucalyptus urophylla x E. grandis. The spring and autumn were the optimal seasons for the explant induction, semi-lignified branches was the most suitable part of explant sampling, the most appropriate disinfection duration with mercuric chloride is 7 minutes for DH32-26 and DH32-28, and 5 minutes for DH32-29.6-BA1.0mg/L and NAA0.4mg/L as plant growth regulator combination was good for explant induction which with the best germination rate.2. There were optimal hormone ratio respectively of the subcultures of 3 clones of Eucalyptus urophylla x E. grandis. the suitable plant growth regulators for the subculture of DH32-26 are 0.5 mg/L 6-BA and 0.2 mg/L NAA, for the subculture of DH32-28 are 0.4 mg/L 6-BA and 0.2 mg/L NAA, and for the subculture of DH32-29 are 0.3 mg/L 6-BA and 0.2 mg/L NAA.3. There was no significant differences between the mediums containing carrageenan and agar as coagulators of subculture proliferation rates of DH32-26, Whereas, there was 8% increased of the subculture proliferation rates of DH32-28 and DH32-29 in the medium containing carrageenan as compared with the medium containing agar. During root induction, induced root in the medium containing carrageenan was far superior to the medium containing agar.4. During the early stage of subculture,5 to 10 days of dark shading was necessary for DH32-26 and DH32-28, opposite the dark shading was unnecessary for DH32-29.5. Wild-mouth bottle was suitable for the subculture of DH32-29 which decreased the cost of nursery stock production, however, it was not good for the subculture of DH32-26 and DH32-28.6. Research revealed differences in inoculation density among different clones, the optimal inoculation density for DH32-26 and DH32-28 was 25 plants per bottle, and 30 plants per bottle was suitable for DH32-29.7. The most suitable root-inducing hormones for DH32-26 were 1.5 mg/L ABTj+0.2 mg/L IBA, and for DH32-28 and DH32-29 were 1.0 mg/L AB1 + 0.2 mg/L IBA.8. The effects of ammonium nitrate (NH4NO3) and nitrate nitrogen (KNO3) at different levels were the same for the rootage of those 3 clones of Eucalyptus urophylla x E. grandis. However, the NH4NO3 of high levels was always inhibits the root growth, and the KNO3 of high levels was good for callus produce in the roots.9. There was no apparent effect of root-promoting in DH32-26, DH32-28 and DH32-29 by using activated carbon, and excessive levels of activity carbon will inhibit the root growth. 10. Two weeks was the best time for rooting and transplanting of those 3 clones which with good survival rate,92.4% of DH32-26,90% of DH32-28,94.4% of DH32-29. The 3 clones of the best transplanting survival rate by using 0.3% potassium permanganate under the big sunshine for 2 days,75.3% of DH32-26, 70.3% of DH32-28,80.7% of DH32-29. The substrate conclude of 60% Coconut bran,25% peat soil and 5% coking chaff was good for transplanting survival rate by compared two different substrates. |
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