Effects Of Cytokinin And Ginsenoside On Adventitious Root Growth And Development Of Panax Quinquefolium

Objective:（1）To clarify the name,origin,place of production and quality of American ginseng in the materia medica,and to provide literature basis for quality evaluation,domestication and resource assessment of authentic Panax quinquefolium L.herbs;（2）To compare and study the differences of"excellent characters and high quality"between imported and domestic American ginseng,so as to lay a foundation for revealing that the authenticity of traditional Chinese medicine has its unique material basis,namely,the unique"chemical type of genuine medicinal materials";（3）To study the influence of phytohormones and ginsenosides on the growth and development of adventitious roots using the controlled platform of Panax quinquefolium L.,and to provide scientific basis for the participation of secondary metabolites in the regulation of"excellent characters and high quality"of American ginseng.Methods:（1）Based on literature examination and literature research,the application history and"excellent characters and quality"of Panax quinquefolium L.were studied;（2）By counting the number and diameter of lateral roots of imported domestic American ginseng,the difference in the"excellent characters"of American ginseng from different origins was clarified;UPLC-Q-TOF-MS was used to compare the chemical composition of main root,lateral root and whole root between imported and domestic American ginseng,so as to clarify the difference in the"high quality"of American ginseng from different origins;（3）Establish the adventitious root platform of Panax quinquefolium L.and draw the adventitious root growth curve;UPLC-Q-TOF-MS was used to determine and clarify the chemical composition differences between the adventitious root of Panax quinquefolium L.and the main root and lateral root of Panax quinquefolium L.original plant;Provide a scientific basis for the subsequent verification of"excellent characters and high quality"by using the adventitious root platform;（4）The adventitious roots of Panax quinquefolium L.were treated with plant hormone cytokinin and ginsenoside.The number of branches and average diameter of adventitious roots were measured by root panoramic scanner and image processing software;UPLC-MS/MS technology was used to detect the content changes of Rg₁,Rb₁and Re in Panax quinquefolium L.adventitious roots after each treatment,and further determine the changes of plant hormones in Panax quinquefolium L.adventitious roots after treatment;Analysis of the effects of cytokinins and ginsenosides on the growth and development of adventitious roots of Panax quinquefolium L..Results:（1）The literature study concluded that Panax quinquefolium L.originated in North America and was successfully cultivated in China in the 1980s.The later cultivation area has been expanding.The modern production areas are mainly concentrated in Northeast China,Shandong,Beijing and other places;The origin of Panax quinquefolium L.has changed to some extent,and the utilization and evolution of its resources has roughly gone through three stages:wild,domestication and introduction;Wild American ginseng has a horizontal spirit body,grayish brown surface,tight horizontal lines,yellowish white section,light and hard body,clear gas,strong fragrance,bitter and slightly sweet taste.It is better to cultivate American ginseng with uniform root strips,tight horizontal lines,solid weight and strong smell.（2）Compared with domestic American ginseng,the number and diameter of lateral roots of imported American ginseng increased significantly;The contents of Ro,Rd₂,F2,Rg₁ and Rh₁ in the taproot of imported American ginseng were significantly higher than those of domestic American ginseng;The contents of Ro,Rd₂,F2 and Rg₁ in the lateral roots of imported American ginseng were significantly higher than those of domestic American ginseng;The contents of Rd,Ro,Rd₂,F2,Rg₁,Rh₁ and Rh₂ of the whole root of imported American ginseng（excluding reed head and fibrous root）were significantly higher than those of domestic American ginseng.Compared with domestic American ginseng,Rg₁/Re and Rg₁/Rb₁of the main root,lateral root and whole root（excluding reed head and fibrous root）of imported American ginseng were significantly increased.（3）The adventitious root growth curve of Panax quinquefolium L.showed an"S"shape.The incubation period was within 20 days after inoculation,and the growth rate was slower,after 10 days for the index growth period.The adventitious root of Panax quinquefolium L.grew actively and proliferated,entered the plateau period from the 35th day,and the increase of fresh weight（FW）and dry weight（DW）reached the peak value and lasted until the 65th day;The results of chemical composition analysis showed that the Rg₁/Re and Rg₁/Rb₁ ratios of adventitious roots were significantly higher than those of Panax quinquefolium L.,and the content of ginsenoside Rf in Panax quinquefolium L.adventitious roots was significantly higher than that of main roots and lateral roots of Panax quinquefolium L..（4）When exogenous cytokinin was added to Panax quinquefolium L.adventitious roots,the adventitious root branches were significantly inhibited and the diameter became thicker at 10μM ZT,the phenotype is in general agreement with that of domestic American ginseng;The contents of ginsenoside Rb₁,Re and Rg₁ in Panax quinquefolium L.adventitious roots decreased after different concentrations of treatment;The content of endogenous cytokinin increased.（5）After treatment with different concentrations of Ginsenoside Rg₁,Re and Rb₁,the number and diameter of adventitious roots of Panax quinquefolium L.increased at low concentration,and the content of ginsenoside and endogenous hormones also changed in varying degrees.Conclusion:（1）By comparison the comparison of the phenotype,component composition and component composition ratio of imported and domestic American ginseng,it is concluded that the number of lateral roots and the diameter of 1 cm under the head of reed of imported American ginseng are larger than those of domestic American ginseng,Rg₁/Re and Rg₁/Rb₁ of imported American ginseng are significantly higher than those of domestic American ginseng,it can be used as the characteristic index of"excellent characters and quality"of authentic herbs;（2）The adventitious root platform of Panax quinquefolium L.is stable and controllable.Ginsenosides Rg₁,Re,Rb₁,and Rf were detected in the indeterminate roots,where the content of ginsenoside Rf in the adventitious root is significantly higher than that in the main root and lateral root of Panax quinquefolium L..The content of Rg₁,Re and Rb₁ is lower than that in the original medicinal material.Due to the short growth cycle and single genetic background of adventitious root,it can be used as an ideal material for controlled experiment;（3）Using the controlled platform experiment of Panax quinquefolium L.adventitious root,it is verified and preliminarily concluded that the interaction between plant hormone cytokinin and ginsenoside regulates the growth of Panax quinquefolium L.root,which lays a foundation for further explaining the genetic mechanism of"excellent characters and quality"of genuine medicinal materials.