Establishment Of Regeneration System For Coix

Coix Lacryma-jobi L.belongs to the family Gramineae Tripasacea Coix,a one-year or perennial herb^[1].Coix is widely distributed in our country,it is a traditional food and medicine crops,and it is also a new kind of feed and has a high economic value.This experiment studies the regeneration system of Coix in order to lay the foundation for future genetic transformation of functional genes and breeding of Coix.In this study,cultivated coix（YY17）and wild coix（YY1,YY9）were used as research subjects.We established an in vitro regeneration system of Coix by indirect organogenesis.This experiment adopted the seed,the embryo,the hypocotyl,the internode,the leaf,the apice,the stem,the aerial root and the bud as explants,focus on researching the effects of five different concentrations of 2,4-D on callus induction,and the effects of hydrolyzed casein,proline,glutamine,mannitol,vitamin C,copper sulphate and silver nitrate on callus proliferation,and the effects of eighteen Differentiation Mediums consisting of 6-BA,NAA,KT,TDZ,2,4-D and GA₃ on regeneration of Coix in indirect organogenesis.Appropriate explants and suitable culture medium were used to establish the in vitro regeneration system of YY17,and regenerated plantlets were obtained.Conclusion as follows:1.The seeds of YY1 and YY9 were sterilized with 75%alcohol and then disinfected with8%sodium hypochlorite for 15 minutes and 10 minutes to obtain sterile seeds.No sterile seeds were obtained from YY17 seeds sterilized with 8%sodium hypochlorite and 0.1%mercury.2.Obtaining a simple and convenient method for gaining aseptic buds,the seeds of YY1and YY9 are directly soaked in 1%aquae hydrogenii dioxidi;YY17 is disinfected with 8%sodium hypochlorite firstly for 10 min and then in 1%aquae hydrogenii dioxidi For aseptic.3.In the callus induction,bud of YY1,YY9 and YY17 explants can induce a compact embryogenic callus,leaves failed to form callus.The remaining explant material induced callus is white or light yellow cotton-like,water stain serious,serious subculture browning.Thus,MS+1mg/L2,4-D+1mg/LNAA as induction media and the bud as explant was more appropriate for the Coix callus induction.4.Silver nitrate has some effect on improving the state of callus and reducing the browning of callus.The subculture medium of callus is MS+1mg/L2,4-D+1mg/L NAA+0.85mg/LAg NO₃.5.The callus induced by YY1 and YY9 buds was placed on different re-differentiation medium for 30 days,and only the green spots differentiation and the increase of the callus mass,and there was no differentiation of shoots.The callus induced by YY17 was inoculated on MS medium supplemented with 2mg/L 6-BA+2mg/L KT,and budding was induced after about 3 weeks of culture.6.The regenerated shoots of YY17 could be rooted on 1/2 MS medium supplemented with 0.5mg/L IBA,finally forming a complete plant.