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Evaluation of Microbial Antagonists for Biological Control of Botrytis cinerea Stem Infection in Cucumber and Tomato 总被引:3,自引:0,他引:3
A.J. Dik G. Koning J. Köhl 《European journal of plant pathology / European Foundation for Plant Pathology》1999,105(2):115-122
Of fifteen isolates of yeasts, filamentous fungi and bacteria and a commercial product, tested in a bioassay with stem segments, eleven isolates consistently reduced incidence of disease and sporulation of Botrytis cinerea Pers; Fr in tomato and seven isolates in cucumber. Several isolates reduced disease by more than 75% in all experiments. Six antagonists that performed well in the bioassays and that were fairly easy to produce in vitro, were selected for further testing in two glasshouse experiments with cucumbers. After application of spores of B. cinerea and the antagonists or the fungicide tolylfluanid to pruning wounds, disease incidence was reduced by 50–100% by all antagonists in both experiments and only in one experiment by tolylfluanid.For Trichoderma harzianum T39, Aureobasidium pullulans and Cryptococcus albidus, biological control efficacy in bioassays with cucumber stem segments was not strongly influenced by temperatures in the range between 18 and 30°C, but at 24°C the efficacy of the three antagonists strongly decreased at relative humidities of 90% and 80% (vapour pressure deficits 0.299 and 0.598kPa, respectively) compared to 100. 相似文献
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苯酚—硫酸法测定普鲁兰含量 总被引:2,自引:0,他引:2
苯酚—硫酸法是测定多糖的常用方法,其基本原理是:选用乙醇除去样品中的单糖、低聚糖等干扰成分,然后用去离子水提取样品中所含的多糖类成分。多糖在浓硫酸作用下,水解成单糖,并迅速脱水生成糠醛衍生物,与苯酚缩合成有色化合物,然后用比色法测定其多糖含量。选用苯酚—硫酸法进行普鲁兰多糖测定条件的研究,获得最佳测定条件为:水浴时间15min,水浴温度100℃,浓硫酸5.0mL,苯酚1.0mL,放置时间5min。 相似文献
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从青海省平安县发病杨树叶片上分离得到菌株 PA-2,其发酵滤液对多种阔叶杂草表现出较好的除草活性。对该菌株的培养特征和16S rDNA基因序列分析后,确定其为短梗霉属出芽短梗霉菌Aureobasidium pullulans。盆栽试验表明,其发酵滤液对供试阔叶杂草猪殃殃、藜、冬葵、酸模叶蓼及禾本科野燕麦的鲜重防效分别达到87.25%、78.46%、82.25%、62.11%、80.27%。作物安全性试验结果表明,其发酵滤液对小麦、蚕豆、青稞很安全,对油菜、豌豆有轻微影响。综上所述,菌株 PA-2具有作为微生物除草剂的开发潜力。 相似文献
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探究出芽短梗霉菌(Aureobasidium pullulans)PA-2脂肽类物质的抑菌活性,并以脂肽类物质的产量为响应值对其发酵条件进行优化,为脂肽类物质的生产与应用奠定理论基础。采用酸沉淀法对脂肽类物质进行粗提,通过原位酸水解-茚三酮显色法对脂肽粗提物进行定性检测,并用琼脂打孔扩散法对其抑菌活性进行测定,通过中心组合设计(central composite design,CCD)构建响应面对其发酵条件进行优化。最终初步判定粗提物为环状脂肽类物质;该物质对金黄色葡萄球菌(Staphylococcus aureus)、酿酒酵母菌(Saccharomyces cerevisiae)、大肠埃希菌(Escherichia coli)、樱桃球腔菌(Mycosphaerella cerasella)和大麦网斑病(Pyrenophora teres)具有明显的抑制作用,抑菌圈分别为3.65、1.95、2.15、1.35、2.18 cm;优化后的最适发酵条件为:接种量6.8%、转速216 r·min -1、温度26 ℃、装液量125 mL、pH 7。在此条件下模型预测的脂肽类物质产量为0.94 g·L -1,实际为0.92 g·L -1,比优化前的产量(0.61 g·L -1)提高了51%。优化后的发酵条件可提高脂肽类物质产量,降低发酵成本,可用于上述有抑制效果的菌株防治。 相似文献
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马铃薯淀粉水解液对茁霉多糖发酵的影响 总被引:1,自引:0,他引:1
以马铃薯为原料,采用双酶法制备的水解液为碳源,对出芽短梗霉D1-11的多糖发酵工艺进行了筛选.通过碳源和二价阳离子的单因素试验发现,经β-淀粉酶制备的水解液较SNase303糖化酶制备的水解液更适合做茁霉多糖的发酵碳源,且脱盐脱色处理会提高多糖的产率.DE值50%的β-淀粉酶糖化液经脱色脱盐处理,在水解液碳源浓度80g.L-1时多糖产量最高,为21.98g.L-1,CaCO3在0.1g.L-1时多糖产量最高,为21.11g.L-1;均匀试验确定的摇瓶培养最佳发酵工艺为:CaCO30.06g.L-1,碳源82.25g.L-1,装液量26.62%,接种量11.99%,pH7.5,茁霉多糖产量可达28.90g.L-1. 相似文献
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本文研究了出芽短梗霉Aureobasidium pullulans菌株Yw1防治储藏期草莓果实灰霉病Botrytiscinerea的效果,并对其防病机制进行了初步探索。结果表明,菌株Ywl可以有效的控制储藏期草莓灰霉病的发生,发病率可由95.1%降至30.5%-55.6%,菌株Ywl产生的挥发性物质可以抑制灰葡萄孢菌丝生长,抑制率达到52.1%。去除菌体的上清液对灰霉菌无明显抑制活性,说明其抗菌作用机制可能是活菌的竞争作用。由此可见,菌株Ywl是1株有应用潜力的生防菌。 相似文献