| This paper centers on the in-vitro propagation of Magnolia officinalis Rehd. et Wils,including sterilization of explants, initiation,callus induced shoot culture, proliferation and rooting culture and domestication and transplantation. The purpose is to find out the best composition of medium and propagation procedure, which would lay a foundation for genetic transformation and variety improvement and application of other biotechnology of Magnolia officinalis Rehd. et Wils , as well as offer a technique theory for its industrial culture of seedling, which in turn makes this research has both economic value and scientific interest. The following are the main results:1.The explants are not only difficult to sterilize but also easily affected by the seasonal factor. According to the collection time and parts of collection, it receives best effect to get the seeds germinating stem of Magnolia officinalis Rehd. et Wils in April, May and June. The best sterilization procedure of the explants is 0.1%HgCl2 for 6minutes after 70% alcohol for 30-45seconds. The average Contamination Rate is only 17.1% while the medial survival rate reaches 70.1%. When refer to the apical buds and the lateral buds, the best sterilization procedure is 0.1%HgCl2 for 8 minutes after 75% alcohol for 30-45seconds. But the average Contamination Rate is 30.3% while the medial survival rate is 69.3%. The most difficult time to disinfect is from July to September, especially for the sterilization of leaves, leafstalks and lateral buds, with the average Contamination Rate reaching up to 60.4% while the medial survival rate is only 17.5%.2.The results of initiation culture indicates that:(1) The best time to catch explants is from April to June and the best parts of collection are apical buds, lateral buds and seeds germinating stem.(2) Using Magnolia officinalis Rehd. et Wils as explants, the callus could be induced on B5 medium with different concentration of NAA. The initial culture speed is greatly affected by the concentration of NAA. When the concentration is 0.1mg·L-1, the initial culture speed comes to the maximal figure, and the medial speed is 9.55days. It can be seen from the above that lower concentration of NAA does good for speeding up the initiation while higher concentration of NAA is preferred by the formation of callus.(3) Together with the addition of differently concentrated 6-BA on MS medium and B5 medium, the average speed of explants on B5 medium reaches 15.85days, which is apparently faster than that of MS medium. B5 medium and MS medium significantly affect the shoot differentiation rate, but the effect on the differentiation rate of callus is not obvious. B5 medium receives better effect in differentiating the shoot and the average differentiation rate is 15.39%, which is higher than that of MS medium. The research on the effect of differently concentrated 6-BA proves that the concentration of 6-BA has a great effect on initiation speed. When the concentration is 4.0 mg·L-1, it obtains the fastest speed and the average speed is 14.28days. Meanwhile, the average callus differentiation rate gets to the highest level, up to 45.95%. (4) All treatments have certain callus formation and a little shoot differentiation on the B5 medium containing different concentration of 6-BA and 2,4-D. The statistical analysis indicates that the concentration of 6-BA and 2,4-D have an extremely apparent effect on the callus differentiation rate. Therefore, the best integration to induce the callus is B5 + 6-BA 3.0mg·L-1 + 2,4-D 3.0mg·L-1. Different concentration 6-BA greatly impacts the shoot differentiation rate, and so does the 2,4-D. Consequently, the best integration to induce shoot differentiation is B5 + 6-BA 4.5mg·L-1 + 2,4-D 2.0mg·L-1。(5) All treatments have certain callus formation and shoot differentiation on the B5 medium containing different concentration of 6-BA and NAA. The statistical analysis indicates that the concentration of 6-BA and NAA have an extremely apparent effect on the callus differentiation rate. Therefore, the best integration to induce the callus is B5 + 6-BA 4.5mg·L-1 + NAA 1.0mg·L-1. Different concentration 6-BA greatly impacts the shoot differentiation rate, and so does the NAA. Consequently, the best integration to induce shoot differentiation is B5 + 6-BA 5.0mg·L-1 + NAA 1.0mg·L-1.3.The experiment on callus shoot inducement culture shows that the concentration of 6-BA and NAA affects callus shoot inducement significantly while the concentration of 2,4-D has nothing to do with it. The concentration of 6-BA is the most important factor to the effect of callus shoot inducement, and then the concentration of NAA, the concentration of 2,4-D is the least important. The best integration of callus shoot inducement is B5+6-BA 5.0mg·L-1+NAA 1.0mg·L-1+2,4-D1.0mg·L-1, by which the shoot induced rate is as high as 61.66%.4.In the proliferation culture, the concentration of 6-BA and NAA significantly affect multiplication coefficient, while the concentration of sucrose doesn't affect it. According to the range analysis, the sequence of influential factors of proliferation culture is found to be 6-BA>NAA>sucrose. The best combination of medium is B5+6-BA 5.0mg·L-1+NAA 0.1mg·L-1+sucrose 15g·L-1, with which the multiplication coefficient gets up to 4.89.5.In accordance with the experiment, it is propitious to promote growth by combining B5 + NAA 0.5 mg·L-1 + GA3 0.3mg·L-1.6.The results of rooting culture reflects that:(1) Basic medium is the primary factor affects the rooting rate, and then IBA followed by NAA. Except NAA, both basic medium and IBA have distinct effect on rooting rate. B5 basic medium has the greatest effect on the seedlings culture rooting rate, the average rooting rate can reach 45.71%. The best combination is B5+IBA 1.0mg·L-1+NAA 1.0mg·L-1, with which the rooting rate climbs up to 62.66%.(2) ABT1 and ABT3 can induce rooting at all concentration. The treatment of HG14:B5 + ABT3 1.5 mg·L-1+ sucrose 20g·L-1 can obtain the highest rooting rate of 61.23%, followed by HG12:B5 + ABT1 3.0 mg·L-1+ sucrose 20g·L-1 of 60.01%. 7.Different methods of training seedling have obvious effect on the survival rate of tissue culture seedling. The best way to cope with them is that: place it 6 days without opening the lip, and then open the lip for 6 days, the average survival rate reaches the top of 92.19%. The second best is to place it 6 days without opening the lip, and then open the lip for 3 days, the average survival rate is 87.02%. Different transplanting mediums have significant effect on the survival rate of seedlings. The favorable transplanting substrate is the sand and garden soil, which should be mixed according to the proportion 1:1, which lead a high average survival rate 86.03%. Another option is the sand, in which the average survival rate is 52.15%.
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