Study On The Interspecific Promotion Of The Growth Of Mixed Planting Camptotheca Acuminata And Taxus Chinensis Var.mairei

Camptotheca acuminata and Taxus chinensis var.mairei are national key endangered plants.Camptothecin compounds contained in C.acuminata and taxane compounds contained in T.chinensis var.mairei can significantly inhibit the growth of cancer cells.These two plants are important raw materials for the production of plant-derived antitumor drugs.In order to obtain a large amount of raw materials for the production of anti-tumor drugs,it is urgent to carry out cultivation of C.acuminata and T.chinensis var.mairei plantations.This paper compares the changes in plant photosynthesis,soil enzyme activity,and soil microbial community structure of three planting models of mixed planting of C.acuminata-T.chinensis var.mairei,single planting of C.acuminata,and single planting of T.chinensis var.mairei in a growing season under indoor control conditions.In order to clarify the interspecific promotion mechanism of C.acuminata and T.chinensis var.mairei from the perspective of soil enzyme activity and changes in soil microbial community structure,the main research results are as follows:1.The plant heights and ground diameters of C.acuminata and T.chinensis var.mairei under the three planting modes of mixed planting of C.acuminata-T,chinensis var.mairei,single planting of C.acuminata,and single planting of T.chinensis var.mairei show that the mixed planting of C.acuminata and T.chinensis var.mairei,the plant height and ground diameter of T.chinensis var.mairei were higher than that of the corresponding single purebred planting group.The net photo synthetic rate(Pn),stomatal conductance(Gs),intercellular C02 concentration(Ci),transpiration rate(Tr)of three model plants under three different light intensities(30%,50%and 100%)were determined.The net photosynthetic rate(Pn)size of C.acuminata and T.chinensis var.mairei treated by each group showed the same rule,that is,the C.acuminata Pn in the mixed group>single planted C.acuminata;T.chinensis var.mairei Pn in the mixed group>single planted T.chinensis Pn.Chlorophyll content in leaves:C.acuminata in the mixed group>single planted C.acuminata;T.chinensis var.mairei in the mixed group>T.chinensis var.mairei single planted.The organic carbon content in the soil under the three planting modes:mixed group>single plantation of C.acuminata>single plantation group of T.chinensis var.mairei;total nitrogen content of soil:mixed group>single plantation group of C.acuminata>single plantation group of T.chinensis var.mairei.2.At different time during the growing season,the main secondary metabolites of the two plants under three planting modes-the contents of paclitaxel,cephalomannine,10-DAB,10-DAT and camptothecin in the leaves of T.chinensis var.mairei showed that the content of camptothecin in the mixed group of camptotheca leaves>camptothecin in single planted leaves Content;the content of taxanes in leaves of T.chinensis var.mairei in the mixed group>the content of taxanes in leaves of T.chinensis var.mairei in single planting.3.From the perspective of the soil microbial community structure of the three planting models,the number of bacteria is relatively large,and the number of fungi is relatively small.However,no matter what period of the growing season,the number of soil bacterial and fungal populations in the mixed group was significantly higher than that in the single planting group;the fungi/bacterial ratio in the mixed group was greater than that in the single planting group.4.The enzyme activities of urease,sucrase,dehydrogenase,protease,and phosphatase in the soil of the three planting modes were determined,indicating that:(1)No matter what period of the growing season,the activities of the above five enzymes are the highest in the soil of the mixed planting group;(2)Soil urease and sucrase activities in two single planting groups:T.chinensis var.mairei single planting group>C.acuminata single planting group;Soil dehydrogenase activity:C.acuminata single planting group>T.chinensis var.mairei single planting group;the soil protease and phosphatase activities of the two single planting groups were different from each other during the whole growth period;(3)Mixing has a greater impact on soil phosphatase and protease activities.In July,the peak growing season,the soil phosphatase activity of the mixed group was 1.57 times and 1.74 times of the single plant group of C.acuminata and the single planting group of T.chinensis respectively.The activity of soil protease was 1.42 times and 1.43 times that of C.acuminata single planting group and T.chinensis single planting group,respectively.In conclusion,the results of the study showed that the growth and main secondary metabolite content of the two plants in the mixed group of C.acundinata and T.chinensis var.mairei and the T.chinensis var.mairei were both increased compared with the single planted C.acuminata and T.chinensis var.mairei.At the same time,mixing improves the total amount of soil bacteria and fungi?the ratio of fungi/bacteria,and enhances the activity of five soil enzymes,especially soil phosphatase and protease.Therefore,the changes of soil microbial community structure and the increase of soil enzyme activity caused by mixing may be an important reason for the mutual promotion of the growth of mixed C.acuminata and T.chinensis var mairei.