Techniques Of Meristem Tip Culture For Production Of Virus-free Sweet Potato

The development status and effects of virus diseases on yield and quality on sweet potato were surveyed and analyzed in this paper in Nanyang city of Henan province,the meaning for the development of virus-free of sweet potato in Nanyang city and the research process of tissue culture and virus elimination techniques were expounded.Based on this,stem section and tip shoot apex of 8 varieties of sweet potato(Ipomoea potato Lam.),including Yushu 4,Yushu 5,Yushu 7,Yushu 12,Yushu 14,Fengchan 1,Beijing 553,Xushu 18,were used as the research on culture in vitro and virus detection.1.The general survey of sweet potato virosis was carried out in 13 counties of Nanyang city and many speciments of this disease were detected by Dot blot-ELISA. The results showed that For cultivated plots and strains,the incidence of sweet potato virosis was 100%and disease plants of no virus-free and that of virus-free were 75.9%and 12.1%,resp..About 6 pathogenic virosis of this disease were identified, including SPFMV,SPLV,SPCFV,SPMMV,C-6 and C-8.2.The detection methods of seeding time a shoot from meristem tip culture of virus-elimination grafted into an indicator plant-Ipomca setosa were experimented. The result showed that Seeding time and grafting time of Ipomca setosa as an indicator plant were suitable in Spring and Autumn.Cuttage grafting and nurse grafting were all adoptable during 1-6 leaves of the stock seeding.3.Stem tip meristems of above varieties of sweet potato(Ipomoea potato Lam.) were used as explants and cultured on MS medium supplemented with different combinations of hormones at different concentrations.The optimum medium for differentiation induction was MS+6-BA 1.0 mg/L+NAA 0.1 mg/L+GA₃ 0.05 mg/L.The optimum medium for rapid propagation and rooting was MS+ NAA 0.2 mg/L.Results of meristem culture was satisfactory in the conditions of 28℃and illumination 14 h/d.Five virus-free varieties were obtained after tube derived lines were detected by means of the test of indicator plants and Dot blot-ELISA.