Study On The Rapid Propagation Technology Of Paulownia Fortunei

Paulownia fortunei is a plant of the Paulownia genus of the Scrophulariaceae family.It is a fast-growing tree species with high economic value.It is used for timber,medicinal and ornamental purposes and has a wide range of uses.In this paper,the young shoots of Paulownia fortunei were used as experimental materials,and rapid tissue propagation technology was used to carry out the selection and disinfection of explants,the selection of medium and hormone ratios,and the selection of transplanting substrates in the process of Paulownia fortunei tissue culture.The preliminary establishment of a rapid tissue propagation technology system for Paulownia fortunei with a good induction effect and a high survival rate was of great significance for maintaining the excellent traits of Paulownia fortunei and improving the quality of tissue culture seedlings.At the same time,the changes of physiological indicators during the shoot proliferation and rooting of Paulownia fortunei were measured,and the factors affecting the shoot proliferation and rooting of Paulownia fortunei were revealed.The main research results were as follows:1.In the selection and disinfection of explants,the young,strong,middle and lower stems growing in the very year should be selected.The best disinfection method was to disinfect with 75% alcohol for 25 s and then disinfect with 0.1% mercuric chloride for 10 min.With this method,the induction rate of Paulownia fortunei reached 86.67%,while the pollution rate was 30.22%,and the browning rate was 12.89%.2.Through conducting experiments on the effect of different basic media on the induction of Paulownia fortunei initial buds,it was found that the most suitable medium for Paulownia fortunei initial buds induction was MS medium;the optimal ratio of medium and hormones for Paulownia fortunei initial bud induction rate was: MS+6-BA 1.5 mg/L+NAA 0.2 mg/L,the induction rate was91.17% and the browning rate was 8.31%.3.The optimal ratio of medium and hormone for Paulownia fortunei subculture was: MS+6-BA 1.5 mg/L+NAA 0.2 mg/L,and the proliferation coefficient was 4.16.In the process of the subculture,the physiological activity changed correspondingly,among which the soluble sugar content increased slowly in the early stage of proliferation and accelerated in the late stage.The soluble protein content showed a trend of ‘down-up-down’.The changing trends of POD enzyme activity and SOD enzyme activity were consistent;both increased first and then decreased,and the enzyme activity reached its peak at21 d of culture.4.The best medium for Paulownia fortunei rooting was 1/2 MS+IBA 0.2mg/L +NAA 0.2 mg/L.During the rooting process of Paulownia fortunei,the content of soluble matter and enzyme activity both changed with the extension of rooting time.The soluble sugar content and the soluble protein content changed consistently,showing a trend of first decreasing and then increasing,and the lowest value was on the 4th day of rooting.POD activity and SOD enzyme activity showed a trend of increasing first and then slowly decreasing,and the enzyme activity reached its peak on the 4th day of rooting.5.In the contrast experiment of different transplanting media,after 30 days of cultivation,the highest transplanting survival rate of Paulownia fortunei was98.89%,the seedling height was 8.17 cm and the basal stem was 3.69 mm when the mixing ratio of the transplanting medium was to be yellow heart soil:coconut bran: river sand=1:2:2.Comprehensive analysis showed that the best plan for Paulownia fortunei tissue culture was as follows: the thicker Paulownia fortunei shoots growing in the very year should be selected as the explants,and the sampling site should be the middle and lower part of the branches.After disinfecting with 75% alcohol for 25 s and 0.1% mercuric chloride for 10 min achieved a good sterilization effect.The optimal ratio of medium and hormone for initial bud induction rate was MS+6-BA 1.5 mg/L+ NAA 0.2 mg/L.The optimal medium and hormone ratio for subculture was: MS+6-BA 1.5 mg/L+NAA 0.2 mg/L,30 days as a subculture cycle.The medium for the best rooting effect was: 1/2 MS+IBA 0.2mg/L+NAA 0.2 mg/L.The mixing ratio of the substrates for transplanting medium was optimized to be yellow heart soil: coconut bran: river sand=1:2:2.