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松针褐斑病菌毒素的研究 总被引:3,自引:0,他引:3
通过对松针褐斑病毒素的培养、提取和生物测定,对培养基的选择、培养方法和时间、毒素提取方法等进行了初步探索。试验结果表明,PDA液体培养基和小麦粒固体培养基最适于该病菌的产生;病菌培养23天所产生毒素最多;毒素浓度越高,其致病力越强;80℃和100℃条件下浓缩获得的毒素提取液的致病力最强;毒素粗提液煮沸20分钟仍不失效,毒素易被活性炭吸附。 相似文献
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纵坑切梢小蠹伴生菌危害机理的研究 总被引:4,自引:2,他引:4
该文对纵坑切梢小蠹伴生菌Leptographium yunnanense的危害机理作了初步研究,结果表明,L.yunnanense在与小伴随侵入后,产生致病毒素对寄主树林进行危害,从而辅助纵坑切梢小蠹成功定殖于寄主树木内,该毒素在低浓度条件下仍维持一定的致病力,进一步表明伴生菌在小蠹虫成功蛀害的过程中具有重要的作用。 相似文献
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枯斑盘多毛孢菌粗毒素的基本性质研究 总被引:4,自引:1,他引:4
本文对松赤枯病菌(Pestalotia funeren Desm.)培养液粗提物的基本性质进行了初步研究。结果表明,松赤枯病菌培养液中有致病物质即毒素存在,该菌在PD培养液中能达到最大产毒量;松针浸出汁对毒素的产量和致病活性没有明显的促进作用,培养15天的培养液有较高的致萎蔫的活性,随着培养时间的延长其致萎活性没有较大的提高。该毒素是一类极性较大的非蛋白类物质,能用甲醇将其从培养液中较好地提取出来。pH值对毒素粗提液致病活性无显著影响,毒素粗提液中活性成分能被活性碳吸附。 相似文献
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为了明确榉树枯萎病菌毒素的致病能力,对榉树枯萎病菌毒素进行了提取及生物活性的测定。结果表明:病原菌毒素滤液的生物活性主要体现在对于榉树胚根生长的抑制作用以及对于榉树幼苗的致萎性。通过对培养液种类、培养温度、培养时间、培养方式、培养环境酸碱度以及光照与否6项指标进行筛选,最终确定使用改良Czapek培养液,在25℃下,持续光照,连续振荡,p H为7的条件下可以获得较多的毒素。毒素对榉树的胚根生长存在明显的抑制作用,毒素的浓度越高,抑制作用就越明显。不同浓度的毒素滤液处理对榉树幼苗的致萎作用不同,浓度越高致萎性也越强。 相似文献
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本文是对肉桂枝枯病病原菌毒素研究的首例报道。生物活性测定显示,病菌知液体培养基中可产生导致内桂嫩梢萎蔫和叶盘褐变坏死的致病毒素。改良Fries液体培养基振荡培养和PD液体培养基青止培养为较好的产毒培养方式。病原菌毒素为非寄主专化性毒素,除肉桂外,还对香樟、马尾松、薇苷菊、卤地菊和番茄等植物具有致萎活性,毒素为弱酸性(pH5.4),对冷、热稳定性强,极性较大,易深于水、乙醇、丙酮、正丁醇+丙桐及乙酸乙酯,部分溶于氯仿,基本不溶于乙醚。研究表明毒素为非蛋白质、多糖及核酸类大分子物质。含毒滤液可能含有糖醛类物质,其致毒活性经乙醇和丙酮纯化后有所增强,经HPLC分离出的组分I可能为毒性成份。肉桂叶盘经毒素处理后,其相对电导率较对照大幅度增加,感病的本地桂比抗病的大叶青化桂增加更为明显。 相似文献
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比较研究了不同生物检测材料及方法在纵坑切梢小蠹伴生菌——云南半帚孢毒素的生物活性检测上的适应性,结果表明该毒素不仅对云南松产生病害作用,对思茅松和华山松同样产生病害作用。用切根幼苗为材料对该毒素进行生测,所需时间虽较短,但幼苗所产生的症状较复杂,不易观察和确定;以松树及其木段为材料将该毒素进行接种试验,则在韧皮部位形成明显的反应区,与接菌产生的反应症状一样,容易确定,但木段上出现反应症状的时间较短,因此,以木段为材料,采用接种法进行该毒素活性检测较好。 相似文献
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对大叶柴胡的不同炮制工艺,采用薄层层析,紫外测定方法进行了化学分析,以探讨不同炮制方法的对春毒性成份-柴胡毒素,乙酰柴胡毒素的消除效果。结果表明:运用湿热干燥法可以达到消除毒性的作用,毒性实验表明,其毒性小于一般药用柴胡,为重新利用大叶柴胡的药用价值提供了依据。 相似文献
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对 3个不同致病的青枯菌菌株和 7个不同抗病性的木麻黄无性系苗的研究得出 ,各菌株对寄主根表吸附量具有显著差异 ,吸附量与致病性呈负相关 :各菌株在寄主根内的增殖量差别明显 ,增殖量与致病性呈正相关。病菌脂多糖 (LPS)对幼苗根的预处理 ,可使其供体菌的吸附量减少5 8.5 % 97.3% ,但胞外多糖 (EPS)对供体菌的吸附量无明显影响。洗去EPS和LPS的菌体较完整菌体对根表的吸附量减少 6 3.3% 74 .2 %。而仅洗去EPS的菌体对根表的吸附有所增加 ,最高达19.1%。各菌体SDS PAGE电泳图谱显示出一定差异 ,其中强毒菌株 6 0 1B具有Rf=0 .35的特异谱带。结果表明青枯菌对木麻黄的致病性与其在寄主根表的吸附情况和在根内的快速增殖具有密切关系。LPS在此病理系统中 ,起着细菌识别因子的作用 ,EPS对LPS进行掩盖 ,二者都是病菌致病性的重要因子 相似文献
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WEI Shuhua LIANG Jun YE Jianren ZHANG Xingyao** . School of Resources Environment of Nanjing Forestry University Nanjing P.R. China . Institute of Forest Ecology Environmental Protection Chinese Academy of Forestry Beijing P.R. China 《中国林业科技(英文版)》2007,6(1):62-68
Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin. 相似文献
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R. E. Bradshaw 《Forest Pathology》2004,34(3):163-185
Dothistroma (red‐band) needle blight has been a problem in plantations of exotic pines in the southern hemisphere for many decades. The prevalence of this disease is currently increasing in the northern hemisphere and is now affecting trees in their native ranges. The fungal pathogen Mycosphaerella pini with its anamorph Dothistroma pini, which is responsible for the disease, produces a toxin, dothistromin, that is closely related to the potent carcinogen, aflatoxin. Understandably this has provoked concern about possible effects on the health of forestry workers. This review gives a broad coverage of literature on both disease and toxin. The fungus has a complicated taxonomy with many synonyms and in most countries only the anamorph is found. It is a necrotrophic pathogen that kills needle tissue and completes its life cycle in the lesion thus formed. Dispersal of the disease is normally by rain splash of conidiospores but there is evidence that long range dispersal has occurred by transport of contaminated plant tissue and by wind/cloud dispersal of spores in air currents. The severity of disease is affected by humidity, temperature and light. There is variation in susceptibility of different Pinus species and some achieve increased resistance with age. The current method of control in southern hemisphere plantation forests is through spraying with copper fungicides and, with P. radiata, increased disease resistance has been achieved through a breeding programme. The dothistromin toxin is a difuroanthraquinone and is similar in structure to the aflatoxin precursor versicolorin B. Part of a gene cluster encoding dothistromin biosynthetic genes has been cloned and this has confirmed parallels between the dothistromin and aflatoxin biosynthetic pathways. Dothistromin produces damaging oxygen radicals by reductive oxygen activation rather than by photosensitization, but is also thought to exert its toxic effects on specific cellular targets. Studies have shown that dothistromin is a weak mutagen and clastogen and is therefore a potential carcinogen. Although the risks to forest workers are considered very low it is prudent to avoid unnecessary exposure during periods when dothistromin levels are likely to be at their peak. 相似文献
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对广东湛江桉树开发中心、吴川县、斗门县、高要县、鹤山县等地桉树青枯病的发病规律进行了研究.结果表明:该菌在病株残体及土壤中可存活3年以上,并保持致病力.垃圾肥不仅含有该菌,而且有利于该菌的繁殖.该病始发期为5月下旬至6月初,7月至9月底为发病高峰期,停止期一般在11月中、下旬.林地径流是病菌短距离传播媒介.桉树根部是该病菌主要侵入途径,其次是根颈部.然后蔓延至枝干部分. 相似文献
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From June through October 2020, symptoms of a branch blight disease were observed on Physocarpus amurensis plants in Harbin City, Heilongjiang Province, China. Leaves on infected branches were chlorotic, with many raised, grey spots forming on the epidermis of diseased branches. Diseased twigs formed semi-buried, small, spherical pycnidia, which were initially light brown and later turned dark. The pathogen was isolated and its pathogenicity was verified with Koch's postulates. Based on morphological characteristics and DNA sequence data the pathogen was identified as Aplosporella longipes. This is the first report of A. longipes in China and the first report of it causing branch blight disease of P. amurensis. 相似文献
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桉树焦枯病病原菌特性的观察 总被引:6,自引:0,他引:6
对桉树焦枯病病原菌3种典型的5隔膜、3隔膜和1隔膜分生孢子进行了研究。5隔膜病原菌致病力最强,3隔膜次之,1隔膜较弱。匀菌剂菌毒清对3种病原菌有明显的抑制作用。 相似文献
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Bamboo blight in hybrid Bambusa pervariabilis × Dendrocalamopsis grandis is caused by the fungus Arthrinium phaeospermum. One component designated as PC with pathogenic activity and a molecular weight of about 27 kDa was obtained from this fungus by ammonium sulphate precipitation, polyethylene glycol concentration, Sephadex G‐100 gel chromatography and Q‐Sepharose Fast Flow anion exchange resin. The toxin PC was shown to cause the same typical symptoms caused by the pathogen itself, although the reaction of the toxin was quicker than the pathogen in all four hybrid bamboo varieties. A threshold toxic dose of 10–20 μg/ml was observed for two resistant varieties, while only 5–10 μg/ml was observed for two susceptible varieties. Moreover, effects of the purified toxic protein on the activities of superoxide dismutase, peroxidase, phenylalanine amonnialyase, polyphenol oxidase, chitinase and β‐1,3 glucanase in the different bamboo varieties were analysed using the impregnation and leaf disc methods. The results showed a positive correlation between the resistance of bamboo and the activities of all six enzymes. The activities of all enzymes except β‐1,3 glucanase decreased over the time course of investigation. These results proved the important role played by toxic proteins in the pathogenicity of A. phaeospermum and their potential for selecting resistant varieties or identify the resistance of this bamboo. 相似文献