System Establishment Of Virus-free Regeneration For Apple Cultivars And Rootstocks

Apple chlorotic leaf spot vitus (ACLSV)、Apple stem grooving virus (ASGV) and Applestem pitting virus are three economically important viruses infecting apple trees worldwide.In this research, the tissue culture seedlings of Fuji Nagafu No.2were used as experimentalmaterials, after light treatment of42℃/16h and darkness treatment of34℃/8h, the stemapex with heating treatment of28、36、44、52and58days were selected, and the growingpoint was used for culture and proliferation propagation. The results indicated that thesurvival rate of the stem apex growing point decreased with the time of heating treatmentpassing by, but the elimination rate increased with that. After heating treatment of58days,ACLSV elimination rate was83.30%, ASGV elimination rate was66.70%, ASPVelimination rate was66.70%.The isolated culture of different apple cultivars (‘Yuhua Precocious Fuji’‘Yanfu6Fuji’)and rootstocks (‘MM116’‘T337’) was studied from primary culture, subculture, rootingculture to transplantation, using MS as basal medium. The results indicated that:(1) Duringthe primary culture, the optimum medium of the four materials was MS+6-BA0.5mg/L+IBA0.1mg+PVP500mg/L. When adding the PVP (500mg/L) into the medium, thecontamination rate and the browning rate of the new explants growth was significantly lowerbelow other concentration, and the survival rate was significantly above the others.(2) In thesubculture, making the concentration of6-BA at0.5and0.6mg/L, the differentiationcoefficient was significantly above others.(3) As the concentration of IBA increased, therooting rate first increased and then decreased.(4) When using saw dust as transplantedmatrix, the survival rate was significantly above other treatments; in addition, the stock hadgreater ability to survive than apple cultivars.In T337explants established system, a high degree of vitrification tissue culture,seriously affecting the propagation system established. we did research on the factors, such asagar, hormone,NH4+and NO3-concent ration, light, which affected the vitrification of tissuecultured microcuttings. Come to a more suitable T337tissue culture propagation methods,MS (NH4+0.75mg/L，K+2.2mg/L)+6-BA0.6mg/L+IBA0.5mg/L (agar8g/L, light2000lux).Not only maintained a high tissue culture propagation coefficient is also significantlyreduced the extent of the glass, to the establishment T337tissue culture propagation system.