Optimization Of Virus-free And Rapid Propagation System For Tissue Culture Of Ginger

Xiaohuang ginger（Zingiber officinale Roscoe）is a local variety that is widely cultivated in the southwest of China.Xiaohuang ginger has a stronger spicy flavor,lesser fiber,and higher medical and economic value than other cultivated varieties.But there are still many limitations in the cultivation,such as growth slow,yield reduction,and degradation of germplasm resources.Plant tissue and cell culture are used to solve these problems.In this study,adopting a variety of methods combined with the experimental techniques of disinfection of ginger bud explants,one-step culture,and induction of microrhizome techniques,we cultured the meristem of ginger bud to obtain complete virus-free ginger plantlets.Then,the disinfection method and culture system conducive to the industrial production of virus-free Xiaohuang ginger were selected.The main conclusions are listed as follows:（1）The ginger buds at the early germination stage were disinfected with 75%ethanol for 1 min and then disinfected with 0.1%g/L Hg Cl₂ for 8 min in spring or winter.The contamination rate of the disinfected explants in the primary culture was the lowest,only16.67%.（2）Ginger buds were soaked in 50oC water for 10 minutes.Then,the virus activity in the explants decreased when 20 mg/L ribavirin was added to the primary medium for the induction of the stem tip.The meristem of the stem tip with a diameter of 2.0 mm was cut from ginger buds,and the growth of stem tips was initiated in filter paper liquid medium,and then transferred to a semi-solid medium containing MS+2.0 mg/L KT+0.2 mg/L NAA+3%sucrose+0.6%agar for culture.After 60 days of culture,the virus-free tissue culture plantlets of ginger were obtained.（3）For the subculture of virus-free plantlets,the optimal subculture medium was MS+2.5 mg/L 6-BA+0.3 mg/L NAA+3%sucrose+0.6%agar,and the propagation coefficient of virus-free plantlets was 5.67.Adding 1.0×10³ Sarocladium strictum conidia could significantly promote the growth and proliferation of tissue culture plantlets during subculture.After 5 times of subculture,virus-free plantlets could be produced in large quantities without any detectable variation in the genetic material of tissue culture plantlets.（4）Microrhizome plantlets with a mass of 125.30 mg could be induced in a tissue culture bottle when 3.0 mg/L paclobutrazol was added into the MS medium.The tissue culture plantlets with microrhizome could be transplanted into the field without acclimatization,and the rate of survival reached 100%after 30 days of transplantation.（5）After 20 days of cultivation in vermiculite:nutrient soil:perlite（2:1:1）,the tissue-cultured plantlets grew well,and the rate of transplanting survival was 100%.In conclusion,in this study,the tissue detoxification and rapid propagation system of ginger was optimized.The system has high efficiency and simple experimental procedure and could be used for the production of virus-free plantlets of Xiaohuang ginger.