天名精内酯酮对小麦白粉病的药效及病菌生长发育的影响

【目的】明确天名精内酯酮对小麦白粉病的药效及其对白粉病菌生长发育的影响。【方法】采用温室盆栽试验，测定天名精内酯酮对小麦白粉病的药效；采用离体叶段法，测定天名精内酯酮对小麦白粉病菌孢子萌发及其菌落扩展的影响；利用生物电镜技术，观察天名精内酯酮对小麦白粉病菌菌丝形态和超微结构的影响。【结果】当质量浓度为1 000 mg/L时，天名精内酯酮灌根和喷雾处理的保护效果与治疗效果分别为80.43%和88.03%与82.69%和88.05%，且2种施药方式处理的防治效果与150 mg/L三唑酮处理差异不显著。天名精内酯酮对小麦白粉病菌孢子萌发无明显的抑制作用，但对菌落扩展存在明显的控制作用，并呈现明显的质量浓度依赖性，有效中浓度（EC₅₀）为105.431 4 mg/L。扫描电镜观察发现，经天名精内酯酮处理后，小麦白粉病菌菌丝和分生孢子形态均发生异常变化，表现为菌丝稀疏、表面皱缩和畸形。透射电镜观察发现，经天名精内酯酮处理后，细胞质发生紊乱；电子致密度明显增大，菌丝坏死；细胞内各种细胞器解体，液泡明显增大，且出现空腔；线粒体肿胀，脊变短，部分脊消失。【结论】天名精内酯酮对小麦白粉病有较高的防效，具有较优的内吸传导性能，兼具保护和治疗双重效果；天名精内酯酮对小麦白粉病的防治作用主要是抑制菌丝的生长；天名精内酯酮对小麦白粉病菌菌丝形态和超微结构的影响不同于常用杀菌剂品种。

Effects of Carabrone on the development of Blumeria graminis

【Objective】 The research tested controlling effects of Carabrone against Blumeria graminis,influence of Carabrone on spore germination and mycelial growth of B.graminis,effects of Carabrone on morphology and ultrastructures of mycelial cell.【Method】 The control effects of Carbrone against B.graminis were examined by means of the pot culture experiment.The effects of Carabrone on spore germination and mycelial growth of B.graminis were examined by means of leave fragment method in vitro.The effects of Carabrone on morphology and ultrastructure of mycelial cell of B.graminis were investigated by means of electronic microscopy techniques.【Result】 Under the 1 000 mg/L concentration,the protective effect and the curative effect of Carabrone treating was 80.43% and 82.69% by irrigation,respectively;the protective effect and the curative effect of Carabrone treating was 88.03% and 88.05% by spraying,trespectively.There was no significant inhibitory effect of Carabrone on spore germination,but it had obvious inhibition on mycelial growth and showed a certain degree of concentration dependence.The scanning electronic microscope study revealed that Carabrone not only inhibited the hyphal growth,but also caused a series of the shape of hyphae and conidium.These changes were generally displayed as irregular swelling,malformed,and shrinkage of hyphae surface.Besides,the transmission electronic microscope study caused a series of marked structural alterations of hyphae,after treated with Carabrone,the swelled part of hyphae and vacuoles of mycelial cell mitochondrion were swollen,the electron dense bodies increased,the mitochondrion irregularly swelled,the swelled part of mycelium was malformed and configuration of mycelial cell was destroyed,etc.【Conclusion】 Carabrone has certain control efficiency to B.graminis,including both protective effect and curative effect.Carbrone mainly inhibits the growth of mycelium.Compared with other fungicides,the changes of morphology and ultrastructures to mycelial cell induced by Carabrone is supposed to be unique.