Study On Tissue Culture Of Three Succulent Plants Of Haworthia In Lilicaceae

Haworthia is a succulent plant of Liliaceae.It becomes an expensive species of orn amental plants due to the unique leaf pattern,crystallinity and rarity.The genus has disad vantage of germination difficulties and low reproductive coefficient by conventional meth ods.In order to preserve the germplasm resources and rapid propagation of fine varieties,it is particularly important to set up tissue culture system of succulent plant of Hawort hia.In this study,H.truncata,H.cooperi var.pilfera and H.bayeri j.D.V enter&s.a.Hammer,which are the kinds of representative plants of Haworthia,has been used as the experimental material.With scapes and leaves as explants,the key factors influencing disinfection,Callus induction,Callus differentiation,plantlets rooting and transplanting ha ve been researched.The main results are as follows:1.With scapes as explants at the stage of explant sterilization.Treatment in 75%etha nol for 30s and 0.1%HgCl₂ for 3min was the optimum scheme for explants sterilization.and the contamination rate could be controlled within 3.5%;With leaves as explants,Treat ment in 75%ethanol for 30s and 0.1%HgCl₂ for 6-9min,The disinfection effect was go od,and the contamination rate could be controlled within 6.5%.2.With scapes as explants at the stage of callus induction,the callus quality was bet ter and the culture time was shorter.The optimum culture medium for callus induction for H.truncata scapes was MS+1.0 mg·L^-1 6-BA+0.1 mg·L^-1 NAA+0.5 mg·L^-1 KT.Whereas t he optimum culture medium of callus induction for H.truncata leaves was MS+0.3 mg·L^-1 NA A+1.5 mg·L^-1 KT.The optimum culture medium of callus induction for H.cooperi var.pilfe ra scapes was MS+1.0 mg·L^-1 6-BA+0.3 mg·L^-1 NAA+1.5 mg·L^-1 KT.Whereas the optimu m culture medium of callus induction for H.cooperi var.pilfera leaves was MS+1.0 mg·L^-16-BA+0.3 mg·L^-1 NAA+1.0 mg·L^-1 KT.The optimum culture medium of callus induction for H.bayeri J.D.Venter&S.A.Hammer scapes was MS+2.0 mg·L^-1 6-BA+0.3 mg·L^-1NAA+1.0 mg·L^-1 KT.Whereas the optimum culture medium of callus induction for H.bayeri J.D.Venter&S.A.Hammer leaves was MS+3.0 mg·L^-1 6-BA+0.5 mg·L^-1 NAA+1.0 m g·L^-1 KT.3.At the stage of callus differentiation,the optimum culture medium of callus differentia tion for H.truncata was MS+1.0 mg·L^-1 6-BA+0.1 mg·L^-1 NAA+0.5 mg·L^-1 KT.The opti mum culture medium of callus differentiation for H.cooperi var.pilfera was MS+1.0 mg·L^-16-BA+0.5 mg·L^-1 NAA+1.0 mg·L^-1 KT.The optimum culture medium of callus differentiat ion for H.bayeri J.D.Venter&S.A.Hammer was MS+1.0 mg·L^-1 6-BA+0.1 mg·L^-1 N AA+1.5 mg·L^-1 KT.4.At the stage of rooting induction,the optimum rooting culture medium for H.truncat e was 1/2 MS+0.5 mg·L^-1 NAA+3.0 mg·L^-1 IBA+10.0 g·L^-1 sucrose+7.0 g·L^-1 activated carbo n.The optimum rooting culture medium for H.cooperi var.pilfera was 1/2 MS+0.5 mg·L^-1NAA+1.5 mg·L^-1 IBA+50.0 g·L^-1 sucrose+7.0 g·L^-1 activated carbon.The optimum rooti ng culture medium for H.bayeri J.D.Venter&S.A.Hammer was 1/2 MS+1.5 mg·L^-1 IB A+30.0 g·L^-1 sucrose+7.0 g·L^-1 activated carbon.Add appropriate amount of activated ca rbon when rooting induction.It can significantly increase the rooting rate of the plantlet and make the plants strong and full.5.At the stage of plantlet refining and transplanting.The regenerated plants have bee n transplanted into cultivation medium was composed of volcanic rock and peat soil an d Perlite（v:v:v=2:1:1）.The survival rate of regenerated plants was 86.0%.