杨梅凋萎病综合防治技术试验

杨梅凋萎病传染性强，发病快，给杨梅生产带来了巨大损失。木质素基材料因来源广泛、价格便宜、且活性官能团较多，已广泛应用于纳米药物递送领域。为寻求具有缓释功能的药剂，以便更好地防控杨梅凋萎病，以苯醚甲环唑 (difenoconazole，以下简称Di) 为供试药剂，用苯甲酸酐对木质素磺酸钠 (LS) 进行疏水性改性后，负载Di制备了纳米颗粒Di@BLS，通过核磁共振氢谱 (¹H NMR)、傅里叶红外光谱 (FT-IR)、扫描电子显微镜 (SEM) 及动态光散射激光粒度仪 (DLS) 等对其结构进行了表征，通过Turbiscan稳定性分析仪 (TSI) 对样品稳定性进行了分析；采用QuEChERs方法提取叶片中的Di，研究Di@BLS在杨梅中的吸收转运情况；最后对收集的杨梅病枝进行致病菌的分离鉴定，并分别采用菌丝生长速率法和盆栽试验法研究了Di@BLS对杨梅凋萎病菌的抑制效果。结果表明：在BLS载体浓度为1%、料药比为5 : 1、质量浓度为0.2%的SDS用量条件下制备的Di@BLS平均粒径为135.2 nm，该配方在大量减少表面活性剂用量的同时，可以保持与苯醚甲环唑微乳剂 (Di ME) 相近的制剂稳定性；吸收转运和田间试验均证实Di@BLS能延缓Di的降解，比Di ME在杨梅体内持留时间更久；菌丝生长速率法测定结果显示，Di@BLS对杨梅凋萎病菌可可毛色二孢菌Lasiodiplodia的EC₅₀值为0.643 μg/mL，与Di ME的接近；盆栽试验结果表明，在200 μg/mL质量浓度下，相比Di ME，Di@BLS可降低杨梅凋萎病发病率2.3%。研究结果表明，所制备的纳米颗粒Di@BLS在杨梅体内具有较长的持效期和较好的抑菌效果，可为杨梅凋萎病的防控提供理论依据。

Experiment on comprehensive control technology of bayberry wilt disease

Twig blight disease has the characteristics of strong infectivity and rapid onset, which has brought great losses to the production of bayberry fruit. Lignin-based materials are widely used in the field of nanomedicine delivery due to their wide source, low price, and more active functional groups. In order to seek agents with slow-release function for better control of twig blight disease, Di@BLS nanoparticles were prepared by hydrophobically modifying sodium lignosulfonate (LS) and loading difenoconazole (hereafter referred to as Di) as a test agent, which was characterized by ¹H nuclear magnetic resonance (¹H NMR), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), dynamic light scattering laser particle sizing (DLS), and the stability of the samples was analyzed by turbiscan stability analyzer (TSI); Di in leaves was extracted by QuEChERs method, and the uptake and translocation of Di@BLS in bayberry were investigated, and finally, diseased branches of bayberry collected for the isolation and identification of pathogenic fungi were carried out. The inhibitory effect of Di@BLS on the bayberry twig blight disease was investigated using the mycelial growth rate method and the pot experiment, respectively. The results showed that the average particle size of Di@BLS was 135.2 nm at a BLS carrier concentration of 1%, a feed/drug ratio of 5 : 1 and a SDS dosage of 0.2% by mass. The optimized formulation could maintain stability similar to that of Di ME while reducing the amount of surfactant. Both absorption transfer and field experiments confirmed that Di@BLS could delay drug degradation and persist longer in bayberry than Di ME. The results of the mycelial growth rate method showed that the EC₅₀ value of Di@BLS against Lasiodiplodia was 0.643 μg/mL, which is close to that of Di ME. In the pot experiment, at the mass concentration of 200 μg/mL, Di@BLS could reduce the incidence of blight of bayberry by 2.3% compared with Di ME. The results showed that the prepared nanoparticles Di@BLS had a long duration and good antifungal effect in bayberry, which provided a theoretical basis for the prevention and control of twig blight disease of bayberry.