| Cerasus campanulata is a good species among ornamental plants.It has the characteristics of beautiful shape,flamboyant color,long period of blooming and so on.However,the resource application of Cerasus campanulata is limited to low bearing,short and difficult seed collection and restricted cutting and propagation.This paper studied the in-vitro propagation of Cerasus campanulata,including sterilization of explants,initiation,proliferation and rooting culture and domestication and transplantation. These studies aimed 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 Cerasus campanulata,and also offer a technique theory for its tissue culture propagation, so this study had an important economic and scientific worth.The main results were as follows:1 There were significant differences between sterilization of explants.The apical buds were disinfected easily,the leaves were difficult and the stems were in the middle.The best sterilization procedure of apical buds was 0.1%HgCl2 for 5 minutes after 70%alcohol for 30-45 seconds,its survival rate was 74.2%;the best sterilization procedure of stems was 0.1%HgCl2 for 7 minutes after 70%alcohol for 1 minute,its survival rate could reach 65.5%;the best sterilization procedure of leaves was 0.1%HgCl2 for 8 minutes after 70%alcohol for 30-45 seconds,but its infected rate was up to 60.7%and its survival rate was only 14.3%.2 The results of initiation culture showed that:(1)Using young branches of Cerasus campanulata as explants,the callus could be induced on MS medium with different concentration of NAA,but the shoot could not.The concentration of NAA had greatly significant effect on the initial culture speed.When the concentration of NAA was 0.1mg·L-1,the initial culture speed reached the fastest,and the average speed was 10.71 days.(2)The callus and shoot both could be induced on MS medium adding different concentration of 6-BA 0.1-5.0mg·L-1.The concentration of 6-BA had greatly significant effect on the initial culture speed, differentiation rate of callus and shoot induction rate.When the concentration of 6-BA was 5.0mg·L-1,the initiation culture speed of explants and differentiation rate of callus achieved their maximum,respectively for 11.07days and 89.47%;while it was 4.0mg·L-1,the shoot induction rate was up to the highest with 52.60%.(3)All treatments had more or less callus formation on the MS,modified WH and modified MS medium containing different concentration of NAA and 6-BA.The statistical analysis showed that basal medium and 6-BA had significant influence on differentiation rate of callus.However,NAA had nothing to do with the speed.They also had obvious effect on shoot induction rate and average number of shoots. The optimal medium for initiation culture was MS+6-BA 2.0mg·L-1+NAA 0.1mg·L-1,which was in favor of growth.The differentiation rate of callus was lower and decreased to 38.89%.At the same time,the shoot induction rate and average number of shoots both reached maximum separately at 94.44%and 3.78.3 In the proliferation culture,the concentration of 6-BA and NAA significantly affected multiplication coefficient.According to the range analysis,the sequence of influential factor of proliferation culture was found to be 6-BA＞NAA＞sucrose.The best combination of medium was MS+6-BA 3.0mg·L-1+NAA 0.01mg·L-1+sucrose 30g·L-1,with which the multiplication coefficient was up to 7.44.4 The suitable medium to promote growth was MS+NAA 0.1 mg·L-1+GA3 0.3mg·L-1.After strong seedling culture,the buds had good growth vigor and higher lignified degree,and the rooting rate and survival rate had been promoted too.5 The results of rooting culture showed that:(1)The effects of the three factors on the rooting rate were IBA＞IAA＞basic medium,and they all had significantly influence.The medium of the highest rooting rate was 1/2 MS+IBA 1.0mg·L-1+IAA 0.5mg·L-1+sucrose 20g·L-1with 82.35%rooting ratio.On this medium,the plantlets had good growth vigor, accelerated rooting speed and the root length was 3-4cm.(2)The concentration of ABT1 and ABT3 could all induce rooting.The treatment of 1/2MS+ABT1 1.5mg·L-1+sucrose 20g·L-1could achieve the highest rooting rate of 93.05%.The following was 1/2MS+ABT3 3.0mg·L-1+sucrose 20g·L-1with 71.30%rooting ratio,but the growth vigor was poor.6 Acclimatization and transplantationDifferent methods of training seedling had significantly effect on the survival rate of tissue culture seedlings.At first,the rooting seedling was moved from the culture chamber,placed under the condition of normal temperature for six days,and then the lid was opened.After six days,the average survival rate reached the highest of 93.81%.Different transplanting mediums had significant effect on the survival rate of seedlings.The optimal transplanting substrate was the perlite and vermiculate which mixed with 1:1,in which the average survival rate was up to 94.07%.
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