Research The Response Mechanism Of Acanthopanax Giraldii Harms On Different Cutting Modes And Shading

Objective:To Study the response mechanism on different cutting modes and intensity of shading of Acanthopanax giraldii to guide the artificial cultivation.Methods:Based on analyse of wild and cultivated populations of Xiaojin County and Maoxian County,established different cutting mode interference group,and determined the annual branch number,annual branch length of each group before and after cutting,Calculated the ratio of after cutting to before cutting of them;Analysised and compared the effects of different cutting patterns on population growth;The wild and cultivated Acanthopanax giraldii of the Maoxian were as the research object,compared the the differences in morphology,photosynthesis,spectrum,and the content of index components,in order to explore the different adaptation mechanism of Acanthopanax giraldii Population to field and cultivation environment;The cultivated Acanthopanax giraldii in Maoxian was as the research object,set up different shading treatment groups,analyzed the growth,photosynthesis,physiology,accumulation of index components,submicroscopic structure to explore the response mechanism of Acanthopanax giraldii to different light intensity.Results:?1?the wild population at an altitude of 3500 meters required a year of convalescence in all cutting mode;is good tolerance for mild,moderate cutting interference;Over harvesting modes such as the cutting in the early stage can promote the germination of new shoots,However,the survival rate of shoots is low,which is not conducive to the sustainable development of Acanthopanax giraldii.In the short term after felling,cultivated population growth is affected,However,cutting new branches can promote the germination of lateral bud of ganglion and internode?2?leaf thickness,leaf area increased,leaf length and width proportion of cultivated populations at lower elevation significantly reduced.the palisade tissue is thick and sponge tissue is thin,when compared with wild populations;photosynthetic rate and light utilization rate are higher;The reflectivity of leaf and canopy spectral in near infrared band are higher,red edge amplitude and red edge area in the first derivative spectra is larger,the position of red edge redshift 10nm;The content of chlorogenic acid and Eleutheroside E in cultivated populations of stem bark in 2009 were lower than the wild population,the two component contents of cultivated populations increased after 6 years.?3?During 8:30¹0:30 and 14:30¹8:30 periods,the reduction of Pn of the CK group was individually caused by stomatal limitation and non stomatal limitation factors;During 14:30¹8:30 period,the reduction of A₁ and A₂ of Pn was caused by non stomatal limitation factors,Light was the main influencing factor to photosynthetic rate.LSP,LCP,Rd of A₁ group and A₂ group were significantly lower than those of group CK,The activities of SOD and POD of them was higher than that of CK group,CAT activity of A₁ and POD activity of A₂ were relatively higher In their respective free radical scavenging system;The contents of chlorogenic acid and Acanthopanax senticosus E were declined after Shadind;Starch grain numbers of A1 and A₂ were less than CK,and the volume of chloroplast of A₁and A₂ were smaller than CK,Significant tacked grana can be observed in A₁ and A₂,Intensive stroma lamellae and a spot of grana can be observed in CK.Conclusion:The wild Acanthopanax giraldii should be harvested in the secondof May after harvesting shoot,namely harvested in every other year once every other year or every two years;excessive harvesting should be eliminated,the cultivated Acanthopanax giraldii can harvested in that year;Light is an important environmental factor that limits the sustainable development of wild Acanthopanax giraldii;severe shading is obviously not conducive to the growth of Acanthopanax giraldii,moderate shading can effectively avoid photoinhibition caused by strong light and protect leaf from being damaged,and the wild Acanthopanax giraldii show some shade tolerance.Therefore,in practice,it is necessary to build a layer of shade nets whose photopermeability rate is 50%,when the light is stronger in summer,dismantle shading network,demolite shading network when the light is weak or in the germination season of new branches,so as to ensure the normal growth of Acanthopanax giraldii.