Study On Early Bolting Differentiation And Endogenous Hormone Changes Of Angelica Sinensis

Using Angelica sinensis（Olive.）Dlies,a local Umbelliferae plant in Gansu,as the test material,this paper used paraffin section system to observe and study the flowering and differentiation process of bolting in Angelica sinensis.Determine the effect of endogenous hormone changes on bolting.In the study of plant endogenous hormone extraction methods,the current four mainstream sample preparation methods:direct extraction method,cross-linked polyvinylpyrrolidone（PVPP）method,dispersion liquid-liquid microextraction（DLLME）method,sep-park C₁₈solid phase The extraction column small column method was used for comparative analysis to determine the most suitable pretreatment method for the extraction of endogenous hormones from Angelica sinensis.The dynamic changes of endogenous gibberellin GA₃,auxin IAA,and ABA content in leaves,stems,and roots of Angelica sinensis at various growth stages were determined by HPLC.Based on this,the relationship between endogenous hormone formation and bolting differentiation during the bolting morphology of Angelica sinensis was determined,and research data was provided for bolting inhibition.The results showed that:（1）Observation of the growth points of Angelica sinensis through the preparation of paraffin sections revealed that the bolting and differentiation process of Angelica sinensis flower buds is roughly divided into four main periods in turn:the leaf primordium differentiation period（undifferentiated period）and the reproductive growth point formation period（bracts and bracts）.Inflorescence primordium differentiation period),inflorescence differentiation period,floral organ differentiation period.（2）The morphological characteristics of the growth points in the four periods are as follows:during the leaf primordium differentiation stage,the growth cones are clustered in the middle of the extremely short and undifferentiated basal stems,and the morphology is flat and no protrusions;During the formation period of the reproductive growth cone,the growth cone showed an enlarged state and a slight protrusion,and continued to develop into a papillary shape and a larger fist shape,and the basal stem also continued to widen and flatten;In the inflorescence differentiation stage,it will continue to grow and widen,and form smaller protrusions（small inflorescence primordium）on the original protrusions until the embryonic form of the compound umbrella inflorescence is formed;At the differentiation stage of floral organs,the number and morphology will continue to increase and increase.The basal stems expand and the stem nodes extend to expose the flower buds,exhibiting bolting morphological characters.（3）Among the four pretreatment methods for comparing the extraction of endogenous hormones,it is found that the separation and purification effect using sep-park C₁₈cartridge is the best,and the extraction content of the three hormones is higher;Direct extraction method and DLLME method,the extracted hormone content is ideal,but the peak shape is more chaotic with more impurities;The treatment method after adding PVPP had the worst effect,and only trace amounts of ABA and IAA were detected.（4）Sep-park C₁₈small column combined with HPLC method was used to detect the content changes of three hormones GA3,IAA and ABA in each growth period of Angelica sinensis leaves,stems and roots.It was found that higher concentration levels of GA₃and ABA in the early leaves of Angelica sinensis bolting were beneficial to bolting,while low concentration levels of IAA were beneficial to bolting.Increasing the ratio of ABA/IAA and ABA/GA₃can promote flowering.The main reason for the difference between leaf and stem changes is that the leaves are mainly used for hormone synthesis and output to the outside.The stem and root respectively play a role in transporting and storing various hormones.Once the stem of the roots of Angelica Sinensis starts bolting,the gibberellin stored in the root is partially transferred to the stem.