In Vitro Culture And Plantlet Regeneration Of Betula Pendula Roth.'Dalecarlica'

Betula pendula Roth.is Blaceaeetu Betula deciduous tree.At present,most of Betulaceae plants use seedling breeding methods,and seedling propagation is easy to produce large genetic variation,in order to obtain more genetic traits consistent plant,plant tissue culture is one of the best way to reproduce.This study uses lignited stems,young stems and young leaves as experiment material to establish in vitro rapid propagation system by primary culture,subculture,multiplication culture,rooting culture,transplanting and domestication,The conclusions have obtained from the experiment:(1)Using 70%alcohol and 0.1%HgCl2 as disinfection reagent to screen for disinfection time on lignited stems(6,8,10,12,15 min)and young stems(2,3,4 min)of Betula pendula Roth.'Dalecarlica',the best sterilization time of young stems is 10 min and the lignited stems is 3 min.(2)Using WPM,MS and 1/2 MS medium as basic medium,exogenous hormones 6-BA.NAA and GA3 are added with different concentrations,and various concentrations of sucrose and agar are added to culture in vitro.The study found that the most suitable medium of lignited stem segments is MS + 0.2 mg/L 6-BA + 0.2 mg/L NAA + 0.2 mg/L GA3 + 20 g/L sucrose + 6 g/L agar,and its differentiation rate is 83.3%.The most suitable medium of young stem segments is MS + 0.5 mg/L 6-BA+ 0.05 mg/L NAA + 0.2 mg/L GA3 + 20 g/L sucrose + 6 g/L agar,and its differentiation rate is 73.3%.The best medium and hormone concentration combination is 1/2 MS + 0.5 mg/L 6-BA + 0.2 mg/L NAA + 2.0 mg/L 2,4-D +20 g/L sucrose + 6 g/L agar,and the highest callus induction rate is 82%.(3)The proliferation of Betula pendula Roth.'Dalecarlica' is mainly by axillary buds,terminal buds grow well,but they have no multiplication.The growth of aseptic seedlings are good in WPM +1.0 mg/L 6-BA + 0.5 mg/L NAA + 20 g/L sucrose + 6 g/L agar,and the multiplication coefficient could reach 4.(4)The seedlings of Betula pendula Roth.'Dalecarlica' are inoculated on 1/2 MS medium of auxin NAA and IBA of 0,0.05,0.1,0.5 mg/L respectively,observation and analysis show that the rooting effect of NAA is better than that IB A of the same concentration,the species and concentration of the best rooting hormone is 0.1 mg/L.The sterile plantlets are transplanted to vermiculite:perlite:the Peat soil is 1:1:2,the survival rate is more than 80%after 15 d.