Study On The Mechanism Of SYAUP-770 Against Botrytis Cinereal And Synthesis And Fungicidal Activity Of Its Salt

Pyrimidinamine is an important heterocyclic compounds,which has been widely used in pesticidal fields because of their biological activities such as insecticidal,fungicidal,herbicidal and so on.A series of pyrimidinamine compounds were synthesized in this laboratory,from which compound SYAUP-770 was screened out in the early stage for further study on mode of mechanism.The study provides theoretical foundation and basis for developing new fungicides and rich varieties of fungicides;in addition,it also lays a theoretical foundation for subsequent screening,structure optimization and research.In this paper,the biological activity of SYAUP-770,absorption and transportation of prevention and control Botrytis cinerea and effect of the morphology and ultrastructure on Botrytis cinerea were determined.In addition,in order to optimize the fungicidal activity of SYAUP-770,SYAUP-770 salts were synthesized and screened out.Conclusions are as follows.This paper studies inhibitory effect at different growth stages,for example,mycelium growth of SYAUP-770 against four kinds of resistance to pyrimethanil Botrytis cinerea,Effect on the Mycelium Dry Weight,Spore formation and germination and Sclerotia produced etc.The results showed that SYAUP-770 obviously inhibited the growth and spore formation and germination of spores.From the EC50 and ECso values,the fungicidal activity of SYAUP-770 against four kinds of resistant strains was better than that of positive control cyprodinil and pyrimethanil.In addition,in PDA(Potato Dextrose Agar)medium,the EC50 values of SYAUP-770 against FS-09,HLD-15 and CY-09 were less than 1 ?g/mL.The results showed that on the PDA and FGA culture media,SYAUP-770 showed high fungicidal activity against the three resistant strains.At the same time,the test also found that the dose increased not only reduce the number of sclerotia,but also the size of sclerotia is smaller,lighter in color from black to gray.When the concentration of SYAUP-770 treatment reached 5 ?g/mL,sclerotium would not produce.While inhibition rate of the positive control cyprodinil reached 100%at 40 ?g/mL,and with the decrease of the concentrations,inhibition rate of sclerotia decreased gradually.When the concentration was 5 ?g/mL,cyprodinil did not affect sclerotial formation,on the contrary,it would promote sclerotium formation.Using in vivo pot spray method,protective and therapeutic effects of SYAUP-770 against Botrytis cinerea and the absorption and transportation performance of SYAUP-770 on cucumber were determined.The results showed that SYAUP-770 possessed protective and therapeutic effects on Botrytis cinerea;and the therapeutic effect in tomato was obvious;while on cucumber plants protective effect significantly was better than the treatment effect,control effect of SYAUP-770 was up to 85.8%;the persistence was relatively long,after spraying 20 days the diseased leaf rate decreased obviously;in addition,SYAUP-770 had lateral absorption and transportation.In this paper,from mycelial morphology and ultrastructure,new pyrimidinamine SYAUP-770 was a little different from existing fungicide cyprodinil.SYAUP-770 can inhibit spore germination of Botrytis cinerea,and make germination number of spores reduce,germ tube turns shorter.What's more,SYAUP-770 streatment also displayed that increased branching of hyphae,atrophy,collapse and deformation of mycelium.Fluorescence microscopy test can be confirmed that the biological membrane of the cell and the spore body were injured.After SYAUP-770 treatment,external material of cell walls undergoes changes under the ultrastructure for 3 days;cell wall structure was destroyed;cell vesiculation was serious;but some cell mitochondria are clearly visible and the number of mitochondria increases,whose ridge becomes greater.It can be inferred that on the one hand,cell membrane was damaged;on the other hand,the cell wall and the outer layer of the cell wall are damaged,which resulted in cell protection ability decreased and speeded up cell death.In this experiment,38 SYAUP-770 salts were synthesized and screened for their activity in vitro and in vivo.These compounds had high in vitro activity against three kinds of Botrytis cinerea,especially against CY-09 and HLD-15 strains the inhibition rate of which was over 90%at 50 ?g/mL,in which the fungicidal activity of four compounds against XM strains was over 80%.In addition,fungicidal activity of 38 compounds was around 90%against Rhizoctonia solani and Corynespora cassiicola.In vivo,the control efficiency of all the compounds were higher than pyrimethanil and cyprodinil,in which control efficiency of trifluoromethylbenzoic acid salt compound 18 and 2-methoxybenzoic acid salt compound 19 was higher than SYAUP-770.