Optimization Of Tissue Culture And Rapid Propagation Technology Of Dendrobium Candidum And Dendrobium Officinale

Bletilla striata is a perennial herb of Orchidaceae,also known as ginger,purple orchid,Gangen,etc.In China,it is mainly distributed in Shanxi,Gansu,Guangxi,Fujian,Sichuan,Zhejiang,Guangdong,Yunnan and Guizhou,etc.The most suitable area is Guizhou Anlong and Xingyi.Using dried tuber as medicine,It can also be used to stanch bleeding,subsidence of swelling and muscle producing,vomit bleeding,traumatic hemorrhage,sore swelling and skin cracks,etc.Dendrobium officinale is a perennial biophytic herb of Dendrobium Sw.Orchidaceae.It is produced in southern Anhui（Dabie Mountains）,eastern Zhejiang,western Fujian,northwest Guangxi,southeast Yunnan and Guizhou.The dried stem is used as medicine,which has the functions of benefiting stomach,generating body fluid,nourishing yin and clearing heat.It is used for heat disease,body injury,dry mouth,thirst,insufficient stomach yin,less food,retching,deficiency heat after disease,excessive fire due to yin deficiency,bone steaming,fatigue heat,dark eyes,flaccid muscles and bones.Bletilla striata and Dendrobium officinale have high medicinal value.In the past,they mainly relied on wild resources.Excessive mining and digging led to the extinction of wild resources.In recent years,tissue culture and rapid propagation of seedlings and artificial cultivation have been carried out,gradually realizing the transformation from wild to domestic,and the market price per kilogram has returned from the high price of 1000 yuan in the wild period to 100 yuan for artificial cultivation.The price will inevitably require the cost of artificial planting of Bletilla striata and Dendrobium officinale to be reduced to a reasonable range.Now the seed and seedling cost accounts for more than 60%of the total cost,and reducing the seed and seedling production cost has become the bottleneck problem restricting the sustainable and healthy development of the industry.Based on plant tissue culture,this study carried out optimization studies on aseptic germination,proliferation and differentiation of procorms,rooting and planting of strong seedlings,and established a set of low-yield seedlings production technology for Bletilla striata and Dendrobium officinale,providing technical support for low-cost seedlings production of Bletilla striata and Dendrobium officinale.The experimental results are as follows:1.Establishment of efficient and rapid propagation technology of Bletilla striataBy adding different Ca²⁺concentration stress,natural additives and growth hormone in the stages of aseptic germination of seeds,strong seedling cultivation and corm induction,etc.The production cycle of Bletilla striata tissue culture was shortened from 10 months to 7 months,In order to gain favorable time for the domestication of Bletilla striata"saddle type"seedlings in the greenhouse from March to May and ensure the emergence of seedlings in the same year,the domestication time in the greenhouse was shortened from 10-15 months to 6-8months.The production cost of Bletilla striata seedlings was reduced by 35%.（1）Germination stage of seed asepsis.Through the selection of natural additives,single hormone,combination hormone and Ca²⁺concentration,the results showed that the most suitable medium for seed aseptic germination was1/2MS+2.47g/LCa Cl2+0.6mg/LNAA+40g/Ll Banana+3%Sucrose+7%Agar.（2）Strong seedling cultivation stage.Through the screening of natural additi-ves,single hormone,combined hormone and Ca²⁺concentration,he most suitable medium for white and strong seedlings was 1/2MS+4.12g/LCa Cl₂+0.5mg/LNAA+40g/L Banana+3%Sucrose+7%Agar.Corm formation stage in tissue culture.The results of natural additives,single hormones,combined hormones and Ca²⁺stress showed that the optimal medium for corm formation stage of tissue culture was1/2MS+4.12g/LCa Cl₂+2.0mg/LNAA+0.5mg/LIBA+40g/L Banana+3%Sucrose+7%Agar.The diameter of corm was large,the growth of tissue culture seedlings was uniform,and the color was bright green.2.Establishment of rapid propagation technique and transplanting technique of Dendrobium officinale（1）The aseptic germinating medium was MS+0.5mg/LNAA+30g/L potato juice,the germinating rate was 97.5%,and the protocorm was dark green with full base.（2）In the process of protocorm increment,the increment medium was1/2MS+0.5mg/LNAA+2.0mg/L6-BA+1.0g/L activated carbon.The protocorm grew well with the best increment degree,many clusters,dark green color and uniform growth.（3）In the process of protocorm differentiation,the differentiation medium was 2/3MS+0.5mg/L NAA+2.0mg/L6-BA+1.0g/L Activated carbon.The average differentiation rate was 96%.The shoots grew well,the stems were strong and the leaves were dark green.（4）In the process of rooting,the rooting medium is 2/3MS+0.5mg/L NAA+30g/L Banana+1.0g/L Activated carbon,the rooting rate is 100%,the rooting plants are strong and the necrosis rate is low.（5）In order to refine the seedlings of Dendrobium officinale,the bottle seedlings were placed in the substrate of greenhouse,the substrate ratio was sawn surface:sawdust=2:1,the survival rate was 100%,the stem was thick,the leaves were expanded,the growth was good,and there was no rotten root.（6）Attached tree cultivation.The height above ground of pear trees attached to Dendrobium officinale was less than 60 cm and more than 60 cm,and there were significant differences in stem length and internode number,but there were no significant differences among the three treatments above 60 cm;There was no significant difference in stem length among different DBH,but there was significant difference in internode number between DBH above 80mm and DBH below 80 mm.Combined with the production practice,the suitable height of pear tree is 0.6～1.5mm,and the suitable DBH condition is more than 80mm.（7）Attached stone cultivation.The stem length,internode number,leaf number and basal diameter of Dendrobium officinale showed certain significant differences under the four treatments;Among them,when the moss thickness was 3-4cm,the stem length of Dendrobium officinale was the longest,with an average of 11.42cm,the number of internodes was the largest,with an average of 11.03,and the basal diameter was the thickest,with an average of 4.49mm,which was significantly different from the other three treatments（P<0.05）,It is proved that the moss thickness of 3～4cm is beneficial to the growth of Dendrobium officinale.