| Caragana stenophylla is a highly resistant deciduous shrub of the genus Caragana,which has many resource and ecological values.However,there are some problems,such as decreasing seed quantity in soil seed bank year by year,defects in traditional seedling and asexual root,and cutting propagation.In order to construct an efficient rapid propagation system for Caragana stenophylla to solve many reproductive problems currently faced by it,the mature seeds of Caragana stenophylla were used as experimental materials,and tissue culture technology and relevant statistical methods were used to analyze and explore.(1)Mature seeds of Caragana stenophylla were used as explants.The effects of different concentrations of plant hormones on adventitious bud induction,proliferation and subgeneration,rooting and seedling cultivation were studied.(2)Callus induction and plant regeneration of caulicles,cotyledons and hypocotyls were investigated using anaphylactoid seedlings of Caragana stenophylla as explants.(3)The shoot induction and plant regeneration of hypocotyls and cotyledons of Caragana stenophylla were studied by using anaphylactoid seedlings as explants.The results are as follows:(1)The mature seeds of Caragana stenophylla were used as explants to study the five experimental processes of disinfection,induction,proliferation,subgeneration,rooting and seedling cultivation: 75% ethanol treatment for 30 seconds and 2%Na Cl O solution treatment for 12 minutes.The best disinfection method for Caragana stenophylla explants was seed shucking and inoculation,with contamination rate of2.23% and survival rate of 66.67%.The bud growth was the best under the conditions of6-BA 0.50mg/L + NAA 0.10 mg/L,and the induction rate was 91.11%.The optimal subculture conditions were 6-BA 0.50mg/L + NAA 0.20 mg/L,the proliferation coefficient was 3.26,and the average plant height was 3.6cm.When IBA was added 0.20mg/L and NAA 0.10 mg/L on 1/2MS as basic medium,the rooting effect was the best,and the rooting rate was 85.4%.The rooting seedlings were tested in bottles for 2-3d and then transplanted into a mixture of peat soil: perlite: vermiculite =5.5:0.5:1.The survival rate of the plants reached 95.53%.(2)In the process of callus induction and plant regeneration of caulicles,cotyledons and hypocotyls,the sterile seedlings of Caragana stenophylla were used as explants to explore the suitable callus induction of caulicles,cotyledons and hypocotyls.Hypocotyls were more suitable for callus induction under dark culture.The optimal medium was6-BA 0.50mg/L + NAA 2.00 mg/L,and the induction rate was 100%.Cotyledons and caulicles were more suitable for callus induction under light culture.The optimal medium was 6-BA 0.50mg/L + NAA 1.50mg/L,and the induction rates were 100% and 97.67%,respectively.However,with the increase of subculture times,the activity of callus decreased and the browning rate of callus increased.Among different media for bud differentiation,6-BA 2.00mg/L + NAA 0.50mg/L was the best medium for callus induction of adventitious buds.The induction rate was 15.67%.(3)The induction and plant regeneration of hypocotyl and cotyledons were investigated by using the sterile plantlets of Caragana stenophylla as explants: the suitable combination of 6-BA 0.50mg/L + IBA 0.50mg/L for hypocotyl adventitious bud induction and plant regeneration was 27.22%;The suitable combination of hormone concentration was NAA 0.05mg/L and TDZ 0.20mg/L,and the induction rate was19.45%.In this study,a complete tissue culture and rapid propagation system was constructed from mature seeds of Caragana stenophylla.In particular,the indexes of plant regeneration through seed induction of adventitious buds have reached the requirements of rapid seedling breeding.Its technical measures can be directly applied to large-scale production,and provide a theoretical basis for further genetic transformation research of Caragana stenophylla in the later stage. |
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