【作者】 郭敬华；

【导师】 刘大群；

【作者基本信息】 河北农业大学 ， 植物病理学， 2007， 硕士

【摘要】 黄瓜白粉病是一种潜育期短、再侵染频繁、流行性强的病害，是黄瓜叶部上的主要病害之一，每年都因白粉病的发生造成严重的经济损失。本研究通过测定经发酵液处理黄瓜白粉病的温室药效试验以及与植物抗病相关酶活性变化规律以期揭示其生理生化方面的作用机理。同时利用荧光染色技术、扫描电镜以及透射电镜技术与细胞学相结合的方法探索其对白粉病菌的作用机理，同时揭示白粉菌以及寄主细胞在超微结构上发生的变化，从不同角度深入探讨抗病机理为今后生产使用打下良好基础。本研究通过温室药效试验表明玫瑰黄链霉菌Men-myco-93-63发酵液对黄瓜白粉病有良好的防效，其中发酵液保护作用的防效为88.64％，治疗作用的防效为82.26％，表明该发酵液对黄瓜白粉病的防治既有保护作用又有治疗作用。通过对喷施发酵液后黄瓜叶片内的抗病相关酶的活性的测定发现，喷施Men-myco-93-63发酵液后黄瓜叶片内POD、CAT、PAL和PPO酶的活性在一定时间内有明显上升的趋势。发酵液用作保护剂时：POD酶活在接菌的2d到3d时即达到峰值，此时酶活为未喷施发酵液时的2.5倍，并且比同时期的清水对照处理的酶活高40％。CAT酶活在接菌第3d时达到最高峰，比对照组高30％。PPO酶活在接菌1d后即升至高峰，比对照组高60％。PAL酶活在第2d到3d达到高峰比同处理的对照组高1.7倍，到第7d时，酶活性和对照组基本相同。发酵液用作治疗剂时：喷施发酵液后，处理组的POD酶活在第1d即达到峰值，此时比清水对照组高约50％。喷药后第1d处理组的CAT酶活上升至最高峰，比同时期的对照处理的酶活性高50％。随后处理组酶活平缓下降，但是始终高于清水对照组。清水对照组的酶活变化不大。接菌1d后，接菌后的处理组PPO酶活上升至高峰，但只比其对照组高20％，随后活性开始下降。喷发酵液后第1d处理组的PAL酶活达到峰值，比同时期其对照组的酶活高47％。荧光显微镜和扫描电镜技术研究发现，发酵液能够降低白粉菌的孢子萌发率，延迟其侵染的时间。在一定程度上抑制了菌丝的生长，使寄主体表的菌丝形态发生一系列异常变化，表现为菌丝扭曲变形，菌落比较稀疏变小，延迟其产孢时间约2d。利用透射电镜技术研究了经发酵液处理后，黄瓜植株叶片以及白粉病菌发生的一系列变化。超微结构观察表明，寄主细胞对病原菌的侵入产生了防卫反应结构，表现为寄主细胞壁加厚，染色加深，在寄主细胞壁下产生结构致密的乳突，在寄主细胞壁与质膜之间有黑色沉积物质。黄瓜白粉菌产生吸器的数目明显减少，吸器畸形，吸器壁增厚，细胞器泡囊化解体，最终吸器坏死，不能从寄主细胞中更好的吸取营养，达到防病的目的。更多还原

【Abstract】 Cucumber powdery mildew is one of the most serious lamina primary disease which is a short delitescence, high frequency intrusion, and strongly epidemic disease on cucumber. It was reported that losing in economy was very seriously because of cucumber powdery mildew. In the research, control effect of the fermentation broth of Stremptomyces roseoflavus Men-myco-93-63 on cucumber powdery mildew were investigated through the efficacy test and several resistance-related enzymatic activities of the leaves of cucumber were detected, which opened out the physiology mechanism. At the same time, I explore the control mechanism of the fermentation broth of Men-myco-93-63 on cucumber powdery by means of fluorescence coloration technique and electronic microscopy as well as cytochemical technology. Ultrastructure changes of the host cell wall and Sphaerothecafuligenea (Schlecht) Poll. were studied. The research will lay the important base work for the production and use of the fermentation broth of Men-myco-93-63 in the future.The significant control effect of the fermentation broth of Men-myco-93-63 on cucumber powdery mildew was proofed through the efficacy test. There are two kinds of control effect of the fermentation. One is the protect effect, which was 88.64%in the test. Another is curative effect, which was 82.26%.Several resistance-related enzymatic activities of the leaves of cucumber were detected, such as peroxidase (POD), catalase (CAT), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO). All of the activities of these enzymes in the treated cucumber seedlings were higher than those in the untreated seedlings during the certain periods. When the fermentation broth of Men-myco-93-63 was used as protect medicament, the activities of POD reached its maximum after treatment from two days to three days, which were 2.5 times higher than the fermentation broth untreated and were 40% higher than water comparison at the same time. The activities of CAT reached its maximum after treatment three days, which were 30% higher than unsettled at the same time. The activities of PPO reached its maximum after treatment one day, which were higher 60% than unsettled at the same time. The activities of PAL reached its maximum degree after treatment from two days to three days, which were 1.7 times higher than unsettled, the treatment activities of PAL is the same as unsettled after seven days. When the fermentation broth of Men-myco-93-63 was used as cure medicament, the activities of POD reached its maximum after treatment one day, which were higher 50% than water comparison at the same time. The activities of CAT reached its maximum after treatment one day, which were higher 50% than unsettled at the same time, then, the activities of treatment were fell gently, which activities of CAT were higher than water comparison all the time. The activities of water comparison were hardly variety. The activities of CAT reached its maximum after treatment one day, which were higher 20% than unsettled at the same time, the activities of CAT were fell gently. The activities of PAL reached its maximum after treatment one day, which were higher 47% than unsettled at the same time.The study showed that the fermentation broth of Men-myco-93-63 reduced Sphaerotheca fuligenea (Schlecht) Poll germination, delayed its intrusion time, the amount of hypha were restrained a certain extent after treatment by the fermentation broth of Men-myco-93-63. The hypha on the host surface had taken place a series of change, such as hypha distortion, clone sparsing and decreesinsing, and which delayed come into being sporule about two days. Being studied by means of TEM, the host cell and Sphaerotheca fuliginea arisesed a series of transformation. Being treated with the fermentation broth of Men-myco-93-63, the infected host cells produced defense structures and material related to infection, including that the host cell wall was thickened and deeply stained, solidity of papilla structure produced under the cell wall, dark material deposited between the cell wall and plasmalemma. The number of haustellum of Sphaerotheca fuliginea was reduced obviously. Haustoria became malformed and the wall thickened, and organelles disintegrated. Finally, haustoria necrotizcd. Haustoria can’t absorb favorably nutrition from the host.更多还原