负载乙蒜素的有机硅/壳聚糖复合乳液的制备及其对烟草青枯病的防治效果OA北大核心CSTPCD

In order to achieve efficient adhesion and slow release of ethylicin on the surface of crops,research was conducted on the organosilicon-chitosan high-adhesion sustained-release system loaded with ethylicin.The basic organosilicon emulsion is prepared by hydrosilylation of silicone oil containing hydrogen and acrylic acid.Ethylicin was uniformly mixed with organosilicon molecules through hydrophobic interactions.Finally,through the electrostatic assembly between chitosan amino groups and organosilicon carboxyl groups,the organosilicon/chitosan composite emulsion loaded with ethylicin was prepared.The leaf wetting and adhesion,stability,particle size,Zeta potential,microstructure,encapsulation efficiency,loading capacity,release rate,bacteriostatic activity,and the control effect on tobacco bacterial wilt of the composite emulsion were observed.The results showed that the organosilicon/chitosan composite emulsion SA6@EC8 loaded with ethylicin was the optimized formulation:the contact angle on tobacco leaf was 14.9º and the surface tension was 20.17 mN/m,showing good wetting performance and good extension on the vertical tobacco leaf surfaces;no layering or precipitation was observed after cold and thermal storage for 14 days,with a Zeta potential of+24.7 mV,an average hydrated particle size of 3.17 μm,an average dry particle size of 750 nm;the emulsion particles were monodisperse under a microscope;the encapsulation efficiency and loading capacity of the composite emulsion for ethylicin reached 94.7%and 55.2%,respectively,and the cumulative release rates of ethylicin at 24,72,and 144 h were 55.4%,75.5%,and 82.3%,respectively,exhibiting a fast-to-slow controlled release characteristic.SA6@EC8 showed excellent plate inhibition activity against Escherichia coli and the pathogenic bacterium of tobacco bacterial wilt-Ralstonia solanacearum.Field trials showed that SA6@EC8 achieved a relative control efficacy of 38.5%against tobacco bacterial wilt.Meanwhile,it was found that spraying SA6@EC8 emulsion on tobacco leaves with a yellowing area of less than 10%makes the leaves turn green after 5 days.However,no such phenomenon was observed when the yellowing area exceeds 50%.In this study,a composite emulsion comprised of organosilicon and chitosan loaded with ethylicin,was successfully developed,which endowed this the ethylicin formulation with exceptional adhesive capability and sustained release performance,achieving good efficacy in preventing and managing bacterial wilt of tobacco,thereby presenting broad applications prospects.