Studies On In Vitro Micropropagation Of Three Ornamental Plants In Zingiberaceae

Zingiberaceae,distributed in the tropical and subtropical regions,are an important resources for development of new cultivars of flowers with high economic value;it is used as foods,ornamentals,drugs,spices,pigments,cosmetics,and fiber plants,etc.In present study,we investigated the effects of different explants,virus-free technology and plant growth regulators on in vitro rapid propagation of Alpinia hainanensis,Curcuma rubrobracteata and Kaempferia marginata,which are ornamental flowers in Zingiberaceae.The main results were as follows:In vitro propagation of Alpinia hainanensis,the mature seeds were used as explants.The results showed that after immersion in the water at 60 °C for one day before disinfect,the germination rate was up to 48.33% when seeds were sowed on MS medium.Seeds sterilized by immersion in concentrated sulfuric acid for 15 min can induce callus and shoots;the callus induction rate was 5.67%;the shoots induction rate was 5.36% and the average number of shoots was 3.1.The best medium for buds propagation was MS+6-BA5.0 mg/L+TDZ 0.5 mg/L+NAA 0.1 mg/L;the rate was 5.74;the time needed was about 20 days;and the average stem length was 3.45 cm.Different organs as explants can not induce callus.Howerver,the seeds can induce callus on the medium MS+6-BA 5.0mg/L+2,4-D 0.5 mg/L when they were treated with concentrated sulfuric acid for 10-15 min.The callus obtained was light yellow,damp,with green dots,and of high quality.The best medium for the callus differentiation was MS+6-BA 2.0 mg/L+TDZ 0.5 mg/L+NAA0.2 mg/L.The callus became green after 20 days;the rate of producing buds was 100%;and got 6.4 buds each callus.In vitro propagation of Curcuma rubrobracteata,buds and young rhizome tips were used as explants.The results indicated an effective protocol for sterilization of Curcuma rubrobracteata explants: firstly,young rhizome tips were served as explants,then sterilized by immersion in 0.1% potassium permanganate for 15 min,in 70% alcohol for one min,and in 0.1% mercuric chloride for 25 minutes.The best medium for buds propagation was MS + TDZ 0.5 mg/L + NAA 0.1 mg/L;the rate was 6.01;and the time needed was about 20days;and the average stem length was 6.51 cm.Root and rhizome tips can induce callus;the latter was better but the quality of the callus inducing was poor.The best medium of callus propagation was MS + 2,4-D 0.3 mg/L + 6-BA 0.5 mg/L + TDZ 0.5 mg/L.The best medium of the callus differentiation was MS + 6-BA 2.0 mg/L + TDZ 0.5 mg/L + NAA 0.2mg/L;the rate of producing buds was 93.33% and got 2.2 buds each callus.The best medium for rooting was MS + NAA 1.0 mg/L.In vitro propagation of Kaempferia marginata,axillary buds were used as explants.The results demonstrated an effective protocol for sterilization of Kaempferia marginata axillary buds: the explants were sterilized by immersion in 70% alcohol for 1 min,then in0.1% mercuric chloride for 8 minutes.The shoot proliferation rate on the medium MS +NAA 0.1 mg/L + 6-BA 2.0 mg/L was 4-5.After the tissue culture of three plants in Zingiberaceae,the most effective protocol for sterilization of Zingiberaceae explants was indicated: rhizome tips were served as explants;and the steriliztion time by immersion in the 0.1% mercuric chloride should be longer.Young reproductive organs should be used for embryonic callus induction such as the young embryo.In respect of the growth regulator,6-BA and TDZ were suitable for buds propagation and callus differentiation.The concentration of 6-BA did not show significant difference in buds propagation and callus differentiation.The appropriate concentration of TDZ was 0.1-0.5 mg/L.NAA was suitable for rooting;the appropriate concentration was0.1-1.0 mg/L.The appropriate concentration of 2,4-D for callus induction of rhizome tip explants of Curcuma rubrobracteata was 0.3-0.5 mg/L.