Study On The Initial,Subculture And Browning Of Tissue Culture Of Smoke Tree(Cotinus Coggygria Scop.)

Cotinus coggygria is an important landscape plant in northern China,is the main tree species of Red-leaf landscape in Xiangshan,Beijing.In recent years,the occurrence of Verticillium wilt has seriously affected the safety of Red-leaf landscape and the health of Cotinus coggygria forest.At present,cotinus coggygria mainly propagates through seed germination,but the low germination rate,long cycle and other factors restrict the production of fine seedlings of Cotinus coggygria.Although some domestic scholars have carried out some explorations on tissue culture of Cotinus coggygria,there are still some key technical problems such as browning,differentiation and so on.So far,no tissue culture system of Cotinus coggygria has been established.In this study,one-year-old tender buds,shoot tips or dormant branches of Cotinus coggygria were used as explants to carry out tissue culture technology exploration.The most suitable medium formula for primary generation,subculture and differentiation of tissue culture process of Cotinus coggygria was screened out.The technical problems such as browning and differentiation were effectively solved,and aseptic culture system was established to provide technical support for obtaining excellent disease-resistant seedlings of Cotinus coggygria.The main experimental results are as follows:(1)In the process of disinfection of explants,0.1%mercuric chloride had better disinfection effect,2%sodium hypochlorite was the second,and 10%hydrogen peroxide had the worst disinfection effect.(2)In germination stage,0.1%mercury was the best disinfectant for 5 minutes,while in growth stage,0.1%mercury was the best disinfectant for 10 minutes.The dormant branches were not suitable for tissue culture as explants.(3)WPM was the best basic medium for primary culture,followed by 1/2MS,and MS had the worst effect.(4)The optimum pH of tissue culture was 5.7.(5)the best medium for inducing differentiation was WPM medium+0.8 mg/L 6-BA+0.4 mg/L NAA+0.01 g/L PVP+1 g/L activated carbon+30 g/L sucrose+2.5 g/L plant gel.(6)Browning can be effectively reduced by adding 0.01%PVP or 0.1 g/L Vc to the medium.