| The efficient method was explored for Rhododendron delavayi Franch in propagation from seed germination and tissue culture. Used effects of different and storage temperatures on seed germination rate to choose which soak and reserve temperature was feasible for seed soak and storage. The shoot tips, stems, leaf and root of Rhododendron delavayi Franch were used as explants to find out the best medium composition and condition of culture, as well as establish a tissue culture and rapid propagation technique system. In the experiment the effective measures were found out to prevent the browning and contamination of explants. The study results were showed as follows:1) The result of different soaks showed that soaking seeds in 0.5% boric acid, distilled water (room temperature) and lukewarm distilled water (30℃) for 24 hours could promote its germination rate, and differences were not significant among the three methods. However, 0.5% boric acid soaking was the most efficient method, the seed germination rate and germination force was 71.08% and 22.9%, and seeds of Ma-xiong Mountain population had the highest germination rate and germination force. The result of different storage temperatures for seeds showed that the room temperature was suitable for short-term (about one month) and 4±1℃was suitable for long-term (about one year) storing seeds of R. delavayi.2) The best medium for seed aseptic germination was 1/4MS + KT 1.0mg/L + CH 300mg/L + sugar 25g/L + carrageenan5g/L. After 45 days culture, the seed germination rate was 73.33%.3) The result of phytocytomine selection was that 1.0mg/L 6-BA and KT could promote growth of terminal bud and axillary bud, but no multiplication, simultaneity, 6-BA could not poison the explants, 0.2mg/L TDZ could not promote growth of terminal bud and axillary bud, but could promote sprout clump growth and form callus.4) Selecting explants: When used the stems of aseptic seedling as explants, the survival rate and multiplication rate were the highest. When used wild plants as explants, the bottom axillary buds were the best, it was effective to reduce pollution. The best time for explants acquisition was in late March to early April. Cutting of shoot tip, the larger was effective. 5) Explants disinfection: 0.1% mercury dichloride and a few drops of Tween as disinfectant solution for 15 min was fit for seedlings. It was fit for shoot tip of wild plant to use 70% alcohol surface disinfection 20s at first, and then use 0.1% mercury dichloride and a few drops of Tween solution for 10min. It was fit for stems of wild plant to use 70% alcohol surface disinfection 30s at first, and then use 0.1% mercury dichloride and a few drops of Tween solution for 15min.6) The best medium for growing on subculture was WPM + TDZ 0.8mg/L + IBA 0.2mg/L + KT 0.0mg/L. After 60 days culture, the increasing coefficient was 6.22.7) The best medium for growing on subculture of shoot tip and stems of aseptic seedlings was WPM + TDZ 0.8mg/L + IBA 0.2mg/L + KT 0.0mg/L. After 60 days culture, the increasing coefficient was 6.51.8) The best medium for callus induction of leaf aseptic seedlings was WPM + TDZ 0.1mg/L + IBA 0.2mg/L + NAA 0.2mg/L. After 60 days culture the inducement rate of leaf callus was 62.22%. The best medium for bud differentiation of callus was WPM + TDZ 0.2mg/L + IBA 0.4mg/L + NAA 0.0mg/L. After 60 days culture the bud rate of leaf callus and the average number of bud of budding callus was 70.59% and 7.25.9) The best medium for bud elongation was WPM+KT0.5mg/L+GA30.2mg/L+AC0.1%. After 45 days culture, the average mass growth of bud was 3.3cm.10) The best medium for making bud strong was WPM.11) The best medium for rooting culture of yang plant of tissue culture was 1/2WPM + NAA 0.50 mg/L + IBA 2.00 mg/L + AC 0.2% + sugar10g/L. After 90 days culture, the rooting rate was 100%, the average root number was 16.6, the average root length was 2.92cm.12) For transplantation of plantlets, the mixture including the soil of the rotten leaves in the forest and perlite was the best material, and the survival of plantlets could be up to 82% after transplanting soil.
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