Study On Hardseedness Release And Tissue Culture Of Albizia Odoratissima(L.f.)benth

Albizia odoratissima(L.f.)Benth not only has beautiful tree shape,straight trunk,strong stress resistance,beautiful wood,but also has effect of improving soil.It has high value in landscape,economic and ecological.However,due to its distribution is less and hard degree of seeds is high,it can't meet the needs of popularization and utilization.Therefore,this paper studies the hardseedness release and tissue culture of Albizia odoratissima(L.f.)Benth.It provides a theoretical basis for the seed propagation and tissue culture of Albizia odoratissima(L.f.)Benth in the future.The hard seeds are treated by hot water and concentrated sulfuric acid.The tissue culture is carried out on the young shoots of aseptic seedlings and the young stem segments of half-year old seedlings.To conduct research on sterilization,initial culture,subculture,strong seedling culture and rooting.The main research results are as follows:1.Effect of seed coat integrity on water absorption and germination of s eeds: after soaking in room temperature water(25?)for 26 h,the seed quality of untreated Albizia odoratissima(L.f.)Benth seeds hardly changed,while that of seeds treated with scrub and acupuncture increased significantly during the whole soaking process.The germination rate of the seeds treated by abrasive paper is 92.22%,the germination rate of the seeds treated by acupuncture is 94.44% and the germination rate of the untreated seeds is 12.22%.According to the preliminary analysis,one of the main reason for the low germination rate and dormancy of Albizia odoratissima(L.f.)Benth seeds is that the seed coat prevents the water from entering the seeds.2.Method of hardseedness release: it is found in the test that the best method of hot water treatment is soaking seeds at 85? hot water,and cooling the water naturally and placing the seeds for 24 hours.In this way,the germination rate,germination potential and germination index are 80.00%,95.56% and 16.17.When the seeds are treated with concentrated sulfuric acid,the optimal treatment time is 20 minutes.By this way,the germination rate and germination potential of Albizia odoratissima(L.f.)Benth are both 100%,and the germination index is 17.37.However,the concentrated sulfuric acid treatment has a negative effect on the peroxidase activity of Albizia odoratissima(L.f.)Benth seedlings.3.Influence of temperature on seed germination: the constant temperature of 25? is the most suitable temperature for seed germination of Albizia odoratissima(L.f.)Benth.In this environment,the germination rate,germination potential and germination index of Albizia odoratissima(L.f.)Benth seeds are 95.56%,80.00% and 16.17.4.Surface sterilization: on the one hand,Albizia odoratissima(L.f.)Benth seeds are protected by the peel during the growth and development and the seed coat surface is smooth,which can reduce the attachment of bacteria.On the other hand,the seeds are treated with 85? hot water before sterilization,which has certain sterilization effect.Therefore,the method that after the seeds were soaked with 75% ethanol for 30 s,they were sterilized with 6% sodium hypochlorite solution or 0.1% mercury chloride solution from 5 to 20 minutes can also get wonderful effect.The maximum contamination rate is only 4.44%.The best way to sterilize the young stem section of Albizia odoratissima(L.f.)Benth is to soak it in 75% ethanol for 30 s and then sterilize them with 0.1% mercury chloride solution for 2 minutes.By this way,the pollution rate is the lowest(2.22%),the Browning rate is lower(6.67%),and the survival rate is the highest(91.11%).5.Initial culture: when cluster bud induction is carried out on the buds of Albizia odoratissima(L.f.)Benth,the optimal medium is MS+6-BA1.0mg/L+ NAA0.3mg/L+30g/L sucrose+7g/L agar.By this way,the tissue culture seedlings grow well,the clubbing bud induction rate is 94.44%,and the proliferation coefficient is 4.57.In the process of cluster bud induction,the number of adventitious buds basically increases at a constant rate.It is found that the peroxidase activity of cluster buds is nearly related to the nitrogen content of the medium.In the medium with high nitrogen content,the peroxidase activity of tissue culture seedlings is also high.In addition,the chlorophyll content of cluster buds is affected by the nitrogen content of the medium and the growth rate of explants.The optimal medium for axillary bud growth in the young stem segment of Albizia odoratissima(L.f.)Benth is MS+6-BA1.0mg/L+NAA0.1mg/L.Under this treatment,the rate of axillary sprout growth is 47.46%.Compared with the young stem segments of Albizia odoratissima(L.f.)Benth,the buds of Albizia odoratissima(L.f.)Benth have the advantages of large proliferation coefficient and fast propagation speed.So the cluster bud induction is the initial culture model which is more suitable for the requirements of tissue culture of Albizia odoratissima(L.f.)Benth.6.Subculture: the most appropriate medium component for subculture of Albizia odoratissima(L.f.)Benth is MS+6-BA1.5mg/L+NAA0.2mg/L+30g/L sucrose+7g/L agar.And the most suitable mode of proliferation is mainly divided into sections and supplemented by plant division.In the process of subculture,in the first 14 days,the plant height of adventitious buds increased slowly.In 15 to 28 days,the plant height of adventitious buds increased rapidly.7.Strong seedling culture: the most appropriate medium formula for strong seedling culture of advant buds of Albizia odoratissima(L.f.)Benth is WPM+ 6-BA 0.1mg /L+ NAA 0.5mg /L.The treated tissue culture seedlings not only perform well in plant height,but also grow well.In addition,The plant have dark green leaves.8.Rooting culture: induced adventitious roots of Albizia odoratissima(L.f.)Benth,the optimum medium formula is 1/4 MS +IBA0.5 mg/L +NAA1.0 mg/L.The explant can directly induce adventitious roots or basal callus is less.The rooting rate is 30.95%.Root length and root number are good.And the roots with lateral roots,which is suitable for transplanting.