The Purification And Rejuvenation Of Siraitia Grosvenorii

Siraitia grosvenorii (Swingle) C. is a speciallocal product grown in Guilin . It reproduces by asexuality which leads to the viruses accumulating from generation to generation . Almost all Siraitia grosvenorii being cultured are infected by Luohanguo Mosaic Diseases at present .The infection causes typical mosaic symptoms, local chlorotic spot ,as well as curling on leaves .Virus infection produces important reductions of quality and yield .Shoot tip culture is an effective way to eliminate the viruses and improve the qualities of many economic plants. S. grosvenorii plantlets in vitro were used as material in this experiment and the elimination luohanguo virus by combing tissue culture of shoot-tip with heat therapy were studied. MS was the basical medium ,in which each of the solid medium was added 4.5% surcose and 0.8%arger, and the medium PH was 5.8~6.0. A series of optimization experiment for cultural medium composition were investgated with a view to accelerate the propagation .of shoot-tip The results show that the best heat therapy medium wasMS+BA0.3+IBA(orNAA)0.1+GA0.1,on which the rate of survival was relative higher and the plantlets could differentiation as normal ,as well as the apical buds were taper and it was good for peeling smaller meristem tips The best medium for shooting was MS+BA1.0+NAA0.05+GA0.1, in this condition ,tips of S. grosvenorii could induce multiple shoots. The medium supplemented with BA0.5~1.0, IBA0.1 and GA0.1 was suitable for subculturing , multiple shoot clumps could produce strong plantlets .100%of the shoot-tip plantlets treated with IBA1.0 and activated carbon 0.1% could developetheir roots ,grew robustly. The survival rate of tansplanting reached 93.33% , the regenerated plantlets could adapt to environment better than the controlled ones.In order to lower the difficullties of peeling shoot tips and to set up a rapid propagation techniques of good quality S.grosvenorii seedling ,we carried out the experiment in two ways: (1)peeling the shoot tips after heat thrapy at 38.5℃ for 7 days ,10 days ,15 days. Plants derived from 0.2~0.5mm heat treated (38.5℃ ;10 days )meristems were 100% free from disease. (2) heat thrapy for 0 day ,7 days and 10 days ,then peeling 1.0~2.0mm shoot tips to cultrure until the plantlets regeneration, and then peeling the shoot tips again in the same way .The results show that heat thrapy 10days twice and peeling the size of the meristems twice from 1.0~1.5mm was suitable to get 100% virus-free plants.