| 10-deacetylbaccatinIII(10-DAB)is an important parent nucleus of semi-synthetic anti-cancer drugs taxol and docetaxel.It is widely distributed in the leaves,branches,bark,roots and seeds.Different species,harvest site and time affected the content of 10-DAB.This study used BP neural network model,established a model to prediction the whole plant biomass of 8-year-old Taxus media var CL,to provide a theoretical method for estimating the total biomass of Taxus media var CL.The content of 10-DAB was determined by high performance liquid chromatography(HPLC),analysis the year dynamic changes of la branches and 2a branches biomass,the year dynamic changes of the contents of 10-DAB in 1a branches and 2a branches,the correlation between the branches biomass and the content of 10-DAB.Analysis the contents of 10-DAB in 1a branches on the 1-9 years old plants.The mam findings are as follows:(1)The model used 85 group data as the network input,based on the plant height,ground diameter,crown width,1a branches and 2a branches biomass from 8-year-old Taxus media var CL,the whole plant biomass as the network output,established the BP neural network model,the structure is(5:15:1).Through several network training,when the model of the hidden layer of neurons is 15 layers,the training network was convergence,the training performance error was minimal,only 0.0018.Using the remaining 15 sets of data,tested the training of the neural network,the maximum absolute error of its 15 sample simulations was 341.4,the minimum absolute error was 5,the average absolute error was 2.7731%.The error of the sample is small,the network of new data recognition capabilities,simulation results have reached the desired results,the network has a good generalization ability,can be used to estimate the biomass of Taxus media var CL in the whole park.(2)8-year-old Taxus media var CL,1a branches and 2a branches biomass from the April beginning increments,after September,the growth of branches began to slow down or stop.April to June,the la branches biomass was doubled increase,July to August,the 1a branches biomass was increase about 50%,then gradually reduced.The variation rule between branches biomass and growth time are as follows:1a branches biomass:y =-0.0035x2 + 1.8698x-28.115,(R2=0.9635,p<0.01);2a branches biomass:y =-0.0006x2 + 0.2898x + 205.72,(R2=0.8307,p<0.01).(3)In the 8-year-old Taxus media var CL,the content of 10-DAB in the 1a branches and 2a branches was the highest in April,then gradually reduced,in October the content of 10-DAB basically stable down.In April,the content of 10-DAB in the 1a branches was 0.1511%,the content of 10-DAB in the 2a branches was 0.0261%.From April to November,the content of 10-DAB in the 1a branches was reduced about 88%.the content of 10-DAB in the 2a branches was reduced about 49%.The variation rule between 10-DAB content and growth time are as follows:The content of 10-DAB in the 1a branches:y = 2E-06x2-0.0013x +0.1983,(R2=0.9589,p<0.01);The content of 10-DAB in the 2a branches:y = 2E-07x2-0.0001x +0.0287,(R2=0.8075,p<0.01).(4)The content of 10-DAB in branches was very significant linear negatively correlated with its biomass(p<0.01).The content of 10-DAB decreased with the increase of branches biomass.The total content of 10-DAB in 1a branches reached the highest in June,the total amount of extraction in the sample reached 132.3mg,followed by July,the total amount of extraction in the sample reached 124.278mg.The total content of 10-DAB in 2a branches reached the highest in April,the total amount of extraction in the sample reached 55.4865mg,less than 50%of the highest point of total extraction of la branches.1-9 years old Taxus media var CL,the content of 10-DAB in the 1a branches change was small in June to August,the content of 10-DAB remained stable,respectively were about 0.12%?0.08%?0.036%.The age less than 10 years old,the content of 10-DAB in the 1a branches is remained stable.The content of 10-DAB in branches was very significant negatively correlated with its biomass.The harvest site is 1a branches,harvest time is in June. |
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