Tissue Culture And Rapid Propagation Of Callistemon Viminalis

Callistemon viminalis,endemic to Australia,is kind of evergreen shrub or small arbor belonging to Mytaceae.It is an excellent ornamental plant of high economic value with bright and bottle-brush-like flowers and a long ornamental period.In this paper,using tender stem segments and leaves as explants,rapid propagation system and regeneration system of Callistemon viminalis were established based on a series of researches on explants sterilization,axillary buds germination,shoots proliferation culture,rooting culture,calli induction and shoots differentiation.The main results were as follows:(1)Sterile system was established from stem segments with buds.It was best to pick up explants in April and May.Soaking the explants in detergent solution for 3-5 minutes,then flush in water for 2?3 hours,immerse in 70%alcohol for 30 seconds,and then disinfect with 0.1%HgCl2 for 8 minutes.These sterilization could achieved the results of 24.44%pollution percentage,20%browning percentage and 56.67%germination percentage.(2)The best medium for axillary buds initial culture was MS + 6-BA(0.2mg/L)+NAA(0.05mg/L),the germination rate was 84.44%,the shoots grew well and the average shoot height was 1.99cm.(3)The best shoot proliferation medium was MS + 6-BA(1.0mg/L)+ NAA(0.15mg/L),the proliferation times was 3.77,the effective shoots rate was 73.33%,and the shoots were robust.(4)The best rooting medium was 1/2MS + IB A(0.25 mg/L)+ NAA(0.2 mg/L)+sucrose(lOg/L),the rooting rate was 94.44%,the average root length was 3.03cm and the average root number was 6.6.(5)The rooted plantlets were grown in water for 3-5 days,and were then transplanted into a cup containing substrate(peat:Perlite =1:1)and cultured in glass house.100%of the transplanted plantlets surved.(6)The best medium for calli induction from leaf explants was MS + 6-BA(2.5mg/L)+ NAA(0.3mg/L)+ sucrose(30g/L)+ agar(7.5g/L)and the induction rate reached 82.22%.The calli were green,moist and condense.The optimum medium for shoots differentiation from calli was MS + 6-BA(3.5mg/L)+ NAA(0.25mg/L),the differentiation rate reached as high as 91.11%,and the shoots grew fast and robustly.(7)When stems segments were used as explants for calli induction,the better induction medium was MS + TDZ(1.5mg/L)+ 2,4-D(0.1mg/L),induction rate was 83.34%.