Research On Virus-free Technique Of Chuzhou Chrysanthemum By Tissue Culture And Application Of Virus-free Plantlets

The status of virus diseases of Chuzhou chrysanthemum [Dendranthema morifolium (Ramat) Tzvel 'chuju'] was surveyed and the main viruses infecting Chuzhou chrysanthemum were identified. Rapid propagation technical system and high yield cultivation technical system of the virus-free plantlets of Chuzhou chrysanthemum were established by stem tip meristematic tissue culture combined with improved heating treatment method. The main results were as the following.1. The main viruses infecting Chuzhou chrysanthemum include Tomato Aspermy Virus (TAV), Potato Virus X (PVX), Potato Virus Y (PVY), and Cucumber Mosaic Virus (CMV) through indicative plant identification, the determination of resistance in Vitro, ELISA, and observe of electron microscopy.2. The most suitable shoot multiplying medium was MS+1.0mg/L 6-BA +0.1mg/L NAA. The most suitable rooting medium was 1/2MS (the concentration of major elements was reduced to l/2)+0.1mg/L NAA. 30g/L sucrose and 6.5g/L agar were added to above two mediums and the PH was adjusted to 5.6. The temperature of culture room was 25±1°C, the light-dark regime was 14/10h (day/night), and the light intensity was 2500 1x.3. The improved heating method was: the rooted plantlets in bottoms were transferred to chamber. The stage-temperature-rise method (32°C ×2d,34°C ×2d,36°C×2d,38 °C×42d) was applied. Light-dark regime was 14/10h (day/night) and light intensity was 2500 lx. After 48 days, the longer stem tips (0.5-0.8mm) were cut off and cultured in multiplying medium to free virus. The stem tips' virus-free ratio was above 83% and the surviving ratio was above 42%.4. High yield cultivation technical system of virus-free plantlets of Chuzhou chrysanthemum was established by field experiments. The virus-free plantlets of Chuzhou chrysanthemum recovered to the character of fine variety. The plants were vigor and strong and no virus was found during the whole growing stage. The yield of virus-free plantlets was increased by 35%, compared with the control. The virus free plantlets was demonstrated and popularized successfully by the model of "research institute + farmer + corporation", through the cooperation with the processing enterprise. The area of the virus-free plantlets was over 100ha, and the increased incoming of farmers was over 1.2million Yuan.