| Dictamnus dasycarpus Turcz is a perennial herbaceous plant of the family Rutaceae.It is called Dictamni Cortex after drying.It is a traditional Chinese medicine with hurricane dehumidification,detoxification and detoxification.Many years of excavation caused the depletion of wild resources,and lack of artificial cultivation environment resulting in poor quality of medicinal materials and low content of medicinal ingredients.Therefore,it is urgent to carry out research on the influence of environmental factors on the main medicinal components of Dictamnus dasycarpus Turcz,and guide the environmental factors in the process of artificial cultivation.Regulating and realizing the quantity and quality of Dictamnus dasycarpus Turcz medicinal ingredients.In this study,two-year Dictamnus dasycarpus Turcz was used as the research object.Under different ultraviolet radiation intensities(UV-A radiation intensity:200 ?W/cm2 and 400 ?W/cm2;UV-B radiation intensity:25 ?W/cm2 and 50?W/cm2)treated for 7 days,by studying the changes of growth photosynthesis,alkaloids,limonin and phenolic compounds in Dictamnus dasycarpus Turcz,the process of plant response from receiving environmental signals to adapting to the reaction was compared,and the differences in response of different tissue sites were compared.It reveals the influence of ultraviolet radiation on the accumulation of Dictamnus dasycarpus Turcz medicinal ingredients,and provides a basis for the efficient cultivation and utilization of Dictamnus dasycarpus Turcz.Below are key research findings:(1)HPLC with acetonitrile-water as mobile phase,gradient elution,simultaneous detection of Dictamnus dasycarpus Turcz active ingredients y-fagarine,limonin,dictamnine,obacunone and fraxinellone at 210 and 236 nm The linear regression coefficient reached 0.999.The recovery rate of the five active ingredients was in the range of 94.98-96.88%.The results were accurate and the repeatability was good.(2)Environmental UV-B radiation has no significant effect on photosynthetic growth and chlorophyll fluorescence indicators such as photosynthesis rate Pn,intercellular CO2 concentration Ci,transpiration rate Trmmol,actual photosynthetic efficiency Y(?)and biomass,stomatal conductance Cond increased and the maximum photosynthetic efficiency Fv/Fm decreased(P<0.05).Increasing environmental UV-A radiation had an enhanced effect on Dictamnus dasycarpus Turcz photosynthetic index(P<0.05),and had no effect on chlorophyll fluorescence index and biomass.(3)18 different metabolites were analyzed in different parts of Dictamnus dasycarpus Turcz tissue(P<0.05),and flavonoids accounted for the largest proportion.Through the analysis of principal component Q value,the comprehensive score of phenolic compounds in stems increased under UV-B treatment,and decreased in leaves;UV-A treatment increased in leaves and stems decreased;under UV irradiation,Q values in roots decreased.The accximulation of phenolic compounds was increased under UV-B treatment.The phenolic compounds accumulated under UV irradiation,and the flavonoids increased and decreased(P<0.05).(4)Ultraviolet radiation significantly increased the content of limonin,dictamnine,obacunone and fraxinellone in Dictamnus aasycarpus Turcz plants.UV-B treatment reduced the content of obacunone in the stems of Dictamnus dasycarpus Turcz leaves;UV-A radiation decreased the content of dictamnine in leaves(P<0.05).Comprehensive analysis of the content of five medicinal ingredients is generally accumulated,and the maximum accumulation of individual medicinal ingredients in plants is 8.6 times.Through the analysis of principal component Q value,UV-A and UV-B treatments can improve the synthesis of medicinal components under different gradients.The scores and high-gradient UV-B radiation treatments showed that the comprehensive scores of the medicinal components of Dictamnus dasycarpus Turcz tissue parts increased and were the highest,indicating that this treatment is the best treatment for accumulating medicinal ingredients.In summary,UV radiation has a certain regulatory effect on the secondary metabolites of Dictamnus dasycarpus Turcz seedlings,which is conducive to the accumulation of Dictamnus dasycarpus Turcz medicinal ingredients,which is of great significance for the future cultivation of medicinal plants Dictamnus dasycarpus Turcz,and at the same time,it also has certain significance for the secondary metabolites of medicinal plants. |
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