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金龟子绿僵菌(Metarhiziumanisoplae)是真菌类生物杀虫剂。其孢子发芽侵入昆虫体壁后可在血腔内大量增殖,引起昆虫死亡。通过研究接种量、种龄、菌种代数等生物因素对金龟子绿僵菌生长及产孢量的影响,并对液—固两步发酵工艺进行了研究。经过优化,得到金龟子绿僵菌产孢的最佳生物参数是接种量2.5g/100g,种龄5～6d;采用固体二代种,培养6d,孢子量可达1.531×1010孢子/g干培养基。金龟子绿僵菌固态培养生物变量优化研究@吴振强$华南理工大学生物工程系!广州510640 相似文献
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为阐明绿僵菌与昆虫免疫抑制蛋白的增效机理,采用浸渍法测定昆虫免疫抑制蛋白FKBP52与金龟子绿僵菌Metarhizium anisopliae对西花蓟马Frankliniella occidentalis的毒力和其体内羧酸酯酶（carboxylesterase,CarE）、谷胱甘肽-S转移酶（glutathione-S transferase,GST）、酚氧化酶（phenoloxidase,PO）及几丁质酶活性的变化。结果显示,金龟子绿僵菌和FKBP52蛋白联合使用对西花蓟马的致死中时LT50为7.32 d,优于绿僵菌单用（10.87 d）或FKBP52蛋白单用的（14.15 d）。金龟子绿僵菌和FKBP52蛋白联合使用9 d时,西花蓟马的累计死亡率达81.11%,显著高于绿僵菌单用（45.56%）或FKBP52蛋白单用的（36.67%）;金龟子绿僵菌和FKBP52蛋白联合使用的协同毒力指数为24.10,表现为增效作用。金龟子绿僵菌与FKBP52蛋白联合使用1 d后,西花蓟马体内CarE和PO活性小于金龟子绿僵菌单用后的活性;联合使用2 d后,西花蓟马体内几丁质酶活性小于绿僵菌单用后的活性,而CarE和GST活性均大于金龟子绿僵菌单用后的活性;联合使用3 d后,西花蓟马体内几丁质酶、CarE和PO活性均大于绿僵菌单用后的活性。表明与金龟子绿僵菌单用相比,金龟子绿僵菌和FKBP52蛋白联合使用后西花蓟马体内CarE、GST、PO和几丁质酶活性抑制或诱导效应与时间有关,这可能是两者具有增效作用的重要机制。 相似文献
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天敌昆虫和生防菌的联合应用对害虫防控具有潜在的增效作用。东亚小花蝽Orius sauteri是目前常用的捕食性天敌之一, 被广泛用于温室蓟马、粉虱等害虫的防治。金龟子绿僵菌Metarhizium anisopliae寄主广泛, 可有效防治多种温室害虫, 且相对安全。为探索东亚小花蝽与金龟子绿僵菌联用的控害效果, 本文在室内和田间条件下研究了二者对烟粉虱Bemisia tabaci和西花蓟马Frankliniella occidentalis的协同控害作用。室内测定结果表明, 绿僵菌孢子悬浮液浓度不大于5×107孢子/mL时, 不会对东亚小花蝽5龄若虫的存活和羽化造成负面影响。室内与温室笼罩条件下, 东亚小花蝽携带绿僵菌的处理能够降低辣椒上的西花蓟马和烟粉虱发生量, 表明东亚小花蝽携带绿僵菌可提高对西花蓟马和烟粉虱的防治效果, 证明了天敌昆虫和生防菌联合应用的可行性, 为生物防治方式多元化应用与推广提供了实践指导。 相似文献
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绿僵菌Metarhizium anisopliae是一类对多种害虫具有高活性的病原真菌。本研究以华北大黑鳃金龟Holotrichia oblita 1龄幼虫为对象,从4株绿僵菌中筛选出1株毒力较高的菌株,命名为M7-9。采用浸渍法对华北大黑鳃金龟1龄幼虫进行毒力测定,结果表明,绿僵菌M7-9的致死率为96.67%,僵虫率为96.67%,致死中时为2.82 d;致死中浓度为1.29×106孢子/m L;绿僵菌M7-9 ITS序列分子鉴定表明该株绿僵菌为金龟子绿僵菌。 相似文献
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棉花是我国重要的经济作物．在农业生产中占有重要的地位。棉花红蜘蛛对棉花生产造成严重的损失．由于长期使用化学农药进行防治,对环境污染严重。金龟子绿僵菌是一种昆虫内寄生菌物,它对寄主的侵染过程包括黏附、孢子萌发、穿透虫体、体内发育和致死。为探明金龟子绿僵菌对棉花红蜘蛛的防治效果．为棉花田害虫防治提供环境友好型药剂,于2011年应用100亿孢子／mL金龟子绿僵菌油悬浮剂对棉花红蜘蛛进行了田间药效试验． 相似文献
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金龟子绿僵菌能够寄生昆虫,也能与植物共生。黏附素MAD1是绿僵菌与宿主互作初期的黏附因子。已知它在昆虫的侵染和致病中起重要作用,但与植物的互作机制报道甚少。为了研究MAD1在绿僵菌与植物共生中的作用,我们通过同源重组构建了金龟子绿僵菌mad1敲除株,并检测了敲除株的生长、产孢、孢子萌发及毒力等生物学特性,进一步利用qRT-PCR分析了MAD1在调节花生免疫响应中的作用。结果显示,与野生型菌株相比,敲除株产孢量降低了43.67%,分生孢子萌发中时为27.69 h,显著长于野生型菌株的13.43 h。敲除株对家蚕的半致死时间LT50为8.9 d,较野生型菌株的7.62 d显著延长。敲除株处理花生6 h后,花生免疫类基因CNGC1、PCD4,抗病基因SWEET10及转录因子WRKY41、MYB86的转录水平出现显著上调,而钙调素CML5、CML19的转录表达受到明显抑制。本研究证明了mad1是金龟子绿僵菌产孢、孢子萌发及毒力的正相关基因,并且MAD1在金龟子绿僵菌与植物相互作用初期,抑制植物抗性级联反应,减弱过敏反应,降低对微生物的抵御能力,同时增强共生信号的传导,这些作用有助于金龟子绿僵菌在花生根组织上定殖。 相似文献
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菜青虫感染金龟子绿僵菌后体内几种保护酶活性的变化 总被引：1，自引：0，他引：1
为了明确菜青虫感染金龟子绿僵菌后体内的防御机制,采用分光光度法测定了菜青虫被金龟子绿僵菌感染后体内保护酶活性的变化。结果表明,用金龟子绿僵菌处理后菜青虫体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)均呈现先上升后下降趋势,反映出菜青虫在金龟子绿僵菌侵染初期防御能力增强,后期降低。其中,SOD、POD和CAT活力分别在接种后36、24和48h达到高峰,说明菜青虫在抵抗金龟子绿僵菌侵染过程中,首先发生作用的保护酶是POD,随后为SOD,而CAT是最后发生作用的保护酶。 相似文献
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Philip R. F. Barrett 《Pest management science》1978,9(5):425-433
Viscous solutions of sodium alginate can be extruded under water in the form of a string which will stick to weeds. The sodium alginate reacts with calcium ions to form an insoluble gel of calcium alginate so that the strings become more firmly attached to the weeds. Diquat dibromide can be incorporated into the alginate and this is slowly released into the water close to the plants. Two experiments are described in which this technique is tested in a fast-flowing river and for localised control in a lake. Diquat dihromide was found to be effective, when formulated with alginate, on Ranunculus spp. in the river and Groenlandia densa in the lake. 相似文献
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In glasshouse and laboratory experiments, calcium alginate gel, produced in situ on wounds by successive dipping in solutions of sodium alginate and CaCl2 gave significant protection against infection by pathogenic isolates of Agrobacterium tumefaciens on carrot discs, tomato cuttings and chrysanthemum cuttings. Gel protection was sometimes equal to that given by strain K84 of A. radiobacter and also operated against a pathogenic isolate insensitive to control by strain K84. Sodium alginate or CaCl2 alone gave little or no protection, suggesting that calcium alginate acted by physically excluding the pathogen from wound surfaces. The use of the method described is discussed for delivery of biological or chemical control agents to plant surfaces whilst also providing protection in its own right. 相似文献
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ABSTRACT When formulated as assimilative hyphae in alginate pellets, the nematophagous fungus Hirsutella rhossiliensis was more active (i.e., parasitized more assay nematodes) in an acidic vineyard soil than in a neutral vineyard soil. To determine whether soil pH explained the difference, fungus activity was measured in soil from the neutral site that had been acidified (by adding sulfuric acid) and in soil from the acidic site that had been neutralized (by adding calcium hydroxide). As hypothesized, the activity of pelletized Hirsutella rhossiliensis was negatively correlated with soil pH. Maximum activity occurred at pH(calcium chloride) 4.5, and activity gradually declined to near zero as the pH increased to 6.5 and rapidly declined to near zero as the pH dropped below 4.0. Assays performed on leached soil samples indicated that the effects of sulfuric acid and calcium hydroxide were largely due to pH rather than to specific ions or osmotic potential. The effect of pH, however, was indirect. Heating the neutral soil to 60 degrees C for 2 h did not alter soil pH or electrical conductivity but increased fungus activity to levels equivalent to those in acidified soil. We conclude that, in these two soils, heat treatment or low soil pH suppresses soil organisms that otherwise interfere with growth of Hirsutella rhossiliensis from alginate pellets. 相似文献
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Ko-ichi OSHIMAN 《Journal of General Plant Pathology》2000,66(3):258-263
Pretreatment with sodium alginate (20 g/m2) prior to application of a biocontrol agent, Pseudomonas fluorescens strain A11RN, enhanced the control turfgrass snow mold caused by Typhula ishikariensis biotype B. Disease severities in two fields relative to untreated control plots were 53% and 61% in plots treated with both
the strain and sodium alginate, which were significantly lower than 69% and 77% in plots treated only with the strain. The
antagonist population remained above the threshold for effective control (ca. 1×107 cfu/cm3) at least for the first month under snow in pretreatment with sodium alginate. The population of the biocontrol agent after
snowmelt on turfgrass was five times higher in sodium alginate-amended plots than in unamended plots. Sodium alginate alone
did not reduce disease severity. Sodium alginate might have supported the survival of the applied strain.
Received 7 June 1999/ Accepted in revised form 20 December 1999 相似文献
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Yasser M. Shabana Zakaria A.M. Baka Gamal M. Abdel-Fattah 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(2):99-111
The bioherbicidal efficacy of different alginate formulations of Alternaria eichhorniae 5 (isolate Ae5), a virulent Egyptian isolate, was compared on waterhyacinth (Eichhornia crassipes). The fungus was formulated as alginate pellets containing mycelium alone, mycelium plus culture filtrate or culture filtrate alone. Each formulation was applied with and without a hydrophilic humectant (Evergreen 500). These formulations were evaluated for disease incidence (DI), and disease severity (DS). Maximum DS, but not DI, was obtained with the alginate pellets of mycelium plus culture filtrate. Alginate formulations supplemented with the hydrophilic polymer were more effective in promoting disease. Physiological changes associated with the treated waterhyacinth plants were determined 3, 6 and 9 days after treatment. Waterhyacinth plants treated with alginate pellets of mycelium plus culture filtrate of Ae5 had the lowest levels of pigments, carbohydrates and relative water content. Infection of waterhyacinth with Ae5 led to a significant increase in total phenols of leaves as compared to control. Penetration of waterhyacinth leaves by the fungus occurred only through the stomata, and the invading hyphae were located in the intercellular spaces of leaf tissues. Cytological changes noted in infected cells included changes in chloroplast, nucleus and mitochondria. Invagination of the plasma membrane, particularly at plasmodesmata was also noticed in infected cells. The associations between the infection process, the physiological disorder and the ultrastructure of infected leaves are discussed. 相似文献
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为研究防控水稻褐飞虱的新型材料，以海藻酸钠和蛋白胨为水相，通过添加由菜油和松香组成的油相，优化油相和水相的比例，制备了松香 ? 海藻酸钠膜剂，并测定了其pH值、黏度、固含量、成膜时间和耐雨水冲刷等理化性质及性能指标；采用稻秆喷雾法测定了松香 ? 海藻酸钠膜剂对褐飞虱的室内阻吸活性和田间防控效果。结果表明:当海藻酸钠、蛋白胨、松香和菜油的质量分数分别为3%、8%、12.5%和10%时，松香 ? 海藻酸钠膜剂的拉丝度、黏度和延展性达到较优值，pH值在6.34~6.91之间，黏度值为108~114 Pa ? s，固含量为38.62%，具有较好的成膜性。室内阻吸活性研究发现:用稀释50倍的膜剂处理后3 d，褐飞虱体重显著降低，减重率高达92.78%，而校正死亡率仅为20%；用稀释100倍的膜剂处理后7 d，褐飞虱的校正死亡率为59.26%。田间防效试验结果表明，膜剂稀释50倍处理对褐飞虱的防控效果与20%异丙威乳油稀释1500倍处理相当，喷施7 d后防控效果分别为64.21%和64.04%。本研究结果表明，松香 ? 海藻酸钠膜剂对水稻褐飞虱具有较好的防控效果，具有潜在应用价值，为田间病虫害的防治提供了新思路。 相似文献
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传统农药易受到环境因子的影响而过早降解，导致利用率低下，利用响应型控释技术对传统农药剂型进行改善是提高农药利用率的有效措施。本研究使用多巴胺改性凹凸棒负载毒死蜱 (CPF)，将海藻酸盐作为包覆材料，利用外源挤出法与Ca2+ 交联，制备了能够对碱性条件作出特定响应的多巴胺改性凹凸棒/毒死蜱/海藻酸钙复合水凝胶 (PRCH)。通过扫描电镜 (SEM)、ζ-电位和比表面积测试 (BET) 对PRCH的形貌和结构进行表征，并研究PRCH在不同pH环境介质中的缓释性能、溶胀性能以及在紫外光和不同温度下的稳定性。结果表明:PRCH对毒死蜱的负载率高达85%，并能够在碱性条件下吸水溶胀，导致海藻酸钙孔道打开甚至结构坍塌，从而释放出毒死蜱。利用Korsmeyer-Peppas模型方程拟合曲线阐释PRCH的缓释机理为:在pH = 5.5的缓冲液中，毒死蜱的释药速率由药物的扩散和水凝胶溶胀共同决定；pH = 7.0时农药传输过程由水凝胶裂解的速率主导；而pH = 8.5时农药自身的扩散在毒死蜱的释放过程中起主要作用，但水凝胶的裂解加速了毒死蜱的扩散。PRCH比毒死蜱标准品拥有更强的紫外稳定性和温度稳定性。本研究表明，PRCH具备优异的载药性能、pH特定响应和绿色环保等优势，在提高传统农药施用稳定性和防治效果等方面具有良好的应用前景。 相似文献
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为了提高阿维菌素B2的农药利用率,以海藻酸钠与壳聚糖为复合载体,采用复凝聚法制备了阿维菌素B2海藻酸钠-壳聚糖包埋颗粒剂,并研究了其理化性质及其在土壤中的释放性能。通过单因素试验筛选出对包埋颗粒剂包埋率影响较大的因素,并进行正交试验,以获得优化制备配方;用红外光谱表征包埋颗粒剂的化学结构,用扫描电子显微镜（SEM）观察其物理形态。采用土壤包埋法研究了其模拟释放性能。结果显示:制备阿维菌素B2海藻酸钠-壳聚糖包埋颗粒剂的优选配方为海藻酸钠质量分数1.5%,壳聚糖质量分数1%,Tween-20质量分数0.75%,投药量m（阿维菌素B2）: m（海藻酸钠）= 1 : 2,油水比[m（油相）: m（水相）] = 1 : 20;所制备的包埋颗粒剂的载药量为22.38% ± 0.25%,包埋率为95.26% ± 0.61%。SEM图像显示,包埋颗粒剂形状不规则;红外光谱数据显示,阿维菌素B2被成功包埋于载体中。土壤中的释放性能试验结果表明:包埋颗粒剂在土壤中突释明显,在前30 d,阿维菌素B2的释放量占80 d总释放量的60%以上;小粒径颗粒剂具有更快的释放速率。粒径150~300 μm和 > 300 μm的包埋颗粒剂释放符合一级动力学方程,粒径150~300 μm和 < 150 μm的包埋颗粒剂亦符合Higuchi方程。 相似文献
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ABSTRACT Fusarium oxysporum f. sp. erythroxyli is being investigated as a mycoherbicide for the narcotic plant coca. Sporulation of the fungus in seven formulations containing different organic substrates and movement of its propagules through soil were studied. The formulations were a granular wheat flour/kaolin (pesta); an extruded wheat and rice flour (C-6); and five alginate pellet products containing corn cobs, soybean hull fiber, canola meal, rice flour, or rice flour plus canola oil. Formulations were incubated at 25 degrees C for 6 weeks in desiccators with various salt solutions to provide nine relative humidities (RH), ranging from 100% (pure deionized water) to 0% (anhydrous (CaSO(4)). Hyphae of F. oxysporum f. sp. erythroxyli grew out of alginate pellets with canola meal, rice, and rice plus canola oil as early as 24 h at 100% constant RH. Alginate pellets of rice plus canola oil and granular C-6 and pesta formulations consistently produced more microconidia, macroconidia, and CFU than the other four formulations at all RH tested. The C-6 formulation produced more propagules than the other formulations at low RH (<53%). Canola meal pellets produced more spores than three other formulations when exposed to fluctuating RH (100 to 75%). The effect of percolating water on spore movement through soil was studied using a plant-pathogenic isolate of F. oxysporum f. sp. niveum. To determine the effect of water percolation on propagule movement, formulations were placed on soil columns and artificial rain was applied. In general, 10-fold fewer CFU were recovered at a 8- to 10-cm depth compared with a 0- to 2-cm depth. 相似文献
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The affinity of various lectins for protoplasts from isolines of wheat differing in their reaction to Puccinia graminis Pers. f. sp. tritici , Ericks and E. Henn. race 21 and for infection structures of the fungus was studied. Protoplasts of both isolines were agglutinated by concanavalin A and soybean lectin and lysed by wheat germ agglutinin. Pokeweed mitogen and wheat germ agglutinin bound to fungal germ tubes and appressoria but not to uredospore walls, substomatal vesicles or infection hyphae.
Viability of protoplasts from either isoline was not affected when they were incubated with uredospores, germlings with and without infection structures or with an extract of the susceptible line, heavily infected by the fungus. No differences between polypeptide fractions prepared from protoplasts of the isolines were detected by sodium dodecyl sulphate polyacrylamide gel electrophoresis. 相似文献
Viability of protoplasts from either isoline was not affected when they were incubated with uredospores, germlings with and without infection structures or with an extract of the susceptible line, heavily infected by the fungus. No differences between polypeptide fractions prepared from protoplasts of the isolines were detected by sodium dodecyl sulphate polyacrylamide gel electrophoresis. 相似文献