The Preliminary Studies On Callus Induction And Redifferentiation Smallanthus Sonchifolius

The strains of Smallanthus sonchifolius were selected as the experimental materials,Tender leaves,axillary buds and crown buds were used as explants.The explants were studied with surface-sterillized with 0.1%HgCl₂,method for screening,callus induction, induction of adventitious bud differentiation,subculture and rooting induction of plantlets,etc. The conclusions were as follows:Study on disinfecting methods of explant.The experimental results show that the sensitivity of explant on 0.1%HgCl₂ was not the same,but the disinfection effects were good. The disinfection processes as follows:The explants were washed in water for 2～3hours, before putting in 70%～75%ethanol for 10～15s and rinsed 3～5 times with sterile deionized water,then the explants were surface sterilized with 0.1%HgCl₂ for 8mins and rinsed 3～5 times with sterile deionized water.Study on induction tests of explant and callus.The results showed that the most suitable explant materials are leaves,axillary buds,tubers crown buds,etc.The study found that there are at least three ways of seedlings differenttiation of explants of Smallanthus sonchifolius,namely,aseptic cuttage type,organogenesis type,organ type.The study results of inducing callus of explant showed that The optimum medium for inducing callus is MS with 1.0～1.5 mg·L^-16-BA+0.5～1.0 mg·L^-1IAA,3%sucrose and 0.6% agar,pH5.8.the most appropriate time of inducing callus is 7～10 daysThe study results of inducing adventitious bud showed that induced effects callus of different explants on different hormones and the ratio are not the same as.The optimum medium of inducing adventitious buds is MS with 1.0 mg·L^-16-BA +0.1 mg·L^-1IAA,3% sucrose and 0.6%agar,pH5.8,and the inducing rate is 79.28%.the most appropriate time for inducing adventitious buds is 60～80 daysThe results for multiplication of adventitious buds show that the callus browning and death can easily happen at the proliferation of cultured.6-BA,NAA,GA3 to the proliferation of adventitious buds the impact of the order are 6-BA,GA3 and NAA.6-BA,NAA,GA3 to the growth the impact of the order are 6-BA,GA3 and NAA.The optimum medium for proliferation of adventitious buds is MS with 1.0 mg·L^-16-BA+0.1 mg·L^-1IAA,3%sucrose and 0.6%agar,pH5.8,and the proliferation rate is 567%.The experimental results for rooting induction show that plantlet of Smallanthus sonchifolius is easily rooting,Major element in medium was more effective in inducing rooting,1/2MS+NAA0.01 mg·L^-1was optimum for rooting,with rooting percentage more than 88.89%.NO obvious effect on the rooting of the different concentrations of NAA was seen, but The NAA could certainly promote the strong seedling,and can sped up the rooting speed.