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从安徽省药菊产区大面积受害显花叶症状的菊花上分离到-株病毒分离物(代号Chm-91)。Chm-91经人工接种能侵染10科30种植物;还可通过桃蚜(Myzus persicae)、萝卜蚜(Hyadaphiserysimi)和菊小长管蚜(Macrosiphoniella sanbornic)以非持久性方式传播。18种感染的植物种子不带毒;Chm-91致死温度65℃~70℃,稀释限点10-2~10-3,体外存活期4~5天。Chm-91粒体球状,直径约30nm;病组织超薄切片可见堆集状内含体。该分离物与番茄不孕病毒(TAV)抗血清呈阳性反应。Chm-91的标准紫外吸光度(A0.1% 260)为4.78,A260/A280比值为1.73;粒体平均分子量为1.835 X 106道尔顿,沉降系数为97.5 S;外壳蛋白由相同的亚基所组成,各亚基含236个氨基酸,亚基的分子量和等电点分别为25100(25K)和5.2;核酸类型为单链RNA,在粒体中的含量是16.9%,有四种大小不同组份,碱基百分比中鸟嘌呤(G)为23.3,腺嘌呤(A)为27.3,胞嘧啶(C)为19.4,尿嘧啶(u)为29.6。#br#根据上述生物学性状,血清学反应,粒体形态及理化特性等。作者认为该分离物隶属于TAv或者它的一个株系。这是为害药菊的一种病毒在我国首次报道。 相似文献
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A04034、A04008和苯氧菌酯、嘧菌酯和肟菌酯等甲氧丙烯酸酯类杀菌剂在盆栽试验中对黄瓜白粉病均表现出优异的保护和治疗活性。其中A04034表现出尤为卓越的杀菌活性,其对黄瓜白粉病的保护作用EC50、EC90为0.98μg/mL、3.12μg/mL,治疗作用EC50、EC90为1.17μg/mL、5.22μg/mL,其保护活性和治疗活性在5种药剂中均为最佳。田间药效试验中,10?4034悬浮剂用5、10、20g.a.i/hm2的剂量第3次施药后7d的防效分别为82.7%、89.3%、91.7%;25%嘧菌酯乳油(阿米西达)10g.a.i/hm2的防效为84.0%;10?4008悬浮剂用5、10、20g.a.i/hm2第3次施药后7d的防效分别为73.2%、86.4%、86.5%。10?4034和10?4008悬浮剂用10g.a.i/hm2的防效均略高于25%嘧菌酯乳油(阿米西达)10g.a.i/hm2的防效,防效无显著差异。 相似文献
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对印楝素A和印楝素B的生物活性进行了研究。在3μg/mL的剂量下处理后24 h,印楝素A和印楝素B对小菜蛾3龄幼虫的拒食率分别为85.3%和80.4%;在5μg/mL的剂量下处理后24 h,对棉铃虫3龄幼虫的拒食率分别为94.9%和80.2%。处理后72 h,印楝素A和印楝素B对斜纹夜蛾3龄幼虫的LC50分别为1.0μg/mL和3.3μg/mL。印楝素A和印楝素B在3μg/mL的剂量下处理后72 h,小菜蛾3龄幼虫的死亡率分别为90.42%和84.11%;在5μg/mL的剂量下处理后72 h,棉铃虫3龄幼虫的死亡率分别为99.1%和100.0%;在0.5μg/mL的剂量下处理后72 h,斜纹夜蛾4龄幼虫体重降低率分别为57.5%和72.73%;在0.8μg/mL的剂量下处理后72 h,棉铃虫3龄幼虫体重降低率分别为84.1%和80.9%。 相似文献
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栽培牧草地蜘蛛种群动态的研究 总被引：3，自引：0，他引：3
1981—1986年在甘肃武威地区栽培牧草地采集蜘蛛隶属13科58种,分布数量较多的有7种。蜘蛛占草地捕食性天敌总量的71.32％。文中揭示了草地蜘蛛种群结构及其季节变化。在牧草生育期中,狼蛛科的种类居优势,占51.97％,平腹蛛科和管巢蛛科各占11.93％、11.40％。7月份蜘蛛混合种群的成蛛中,雄蛛数量最少,占27.06％,其蛛态结构随季节而变化,6月成蛛数量最高,占40.78％。蜘蛛种群的数量消长,随作物、牧草生育期和利用年限不同而有差异。3月上旬平均气温4.7℃时,蜘蛛始出土,4月上旬气温7.2℃时,普遍在地面活动。温度和光照强度的日变化和季节变化,明显地影响蜘蛛日活动数量的变化。耕作和7月上旬的降雨,是影响草地蜘蛛数量的重要原因。 相似文献
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近年青岛地区栽培的巨峰系葡萄幼穗期出现了一种新病害,其特征是幼穗轴发生腐烂。据调查,其发病率一般为26%左右,严重地块病穗率可达63%以上。 相似文献
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Flame weeders are a valuable weed management tool for organic growers and potentially for non-organic producers, if the number of registered herbicides continues to decrease. However, they have a number of problems including low-energy efficiency, fire risk and reduced performance in windy conditions. Steam has been shown to be a superior means of heat transfer to weeds and therefore steam weeders should outperform flame weeders. However, producing sufficient quantities of steam on tractor-mounted equipment has been problematic, because the standard designs of pressurised steam boilers are ill-suited for agricultural use. The 'direct-fired steam' weeder described here, is considered to resolve this problem, by spraying water as a fine mist directly into hot exhaust gases from a burner, causing it to evaporate quickly, thus negating the needs for a pressurised system. This design is diesel powered, but could also be run on renewable fuels such as vegetable oil, addressing concerns about the use of non-renewable 'fossil fuels' for thermal weeding. This approach is considered both effective in terms of steam generation and sufficiently practical and low enough in inherent risk for agricultural use. Production of commercial steam weeders based on this concept has commenced in New Zealand. 相似文献
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The molluscicide Frescon (N-(triphenylmethyl)morpholine) induces prolonged, irreversible contractions (contractures) in the isolated heart ventricle, penis retractor, and foot muscles of the aquatic snail Lymnaea stagnalis. It also causes contracture of the penis retractor muscle, but not the heart ventricle, of the terrestrial snail Helix aspersa. Since Frescon-induced contracture is not accompanied by a depolarization of the sarcolemma of Lymnaea heart ventricle muscle cells, it is suggested that the action of this molluscicide is associated with a membrane potential-independent activation of the contractile machinery. The rapid response of Lymnaea musculature to Frescon suggests that the direct contracture-inducing action of this molluscicide could explain its toxicity to the whole animal. 相似文献
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J. C. Felton 《European journal of plant pathology / European Foundation for Plant Pathology》1969,75(1):31-41
The influences on pest control that are external to the pesticide industry are discussed first. The complexity of the interrelationship between the five main parties to the pesticide controversy (the farmer, the public, the pesticide manufacturer, wild life interests and the government) explains in some measure the intensity of the controveersy itself. It is to be hoped that with increasing knowledge all parties will be able to move together along an agreed, optimum course.The responses within pest control in general, and the pesticide industry in particular, to these external influences are then discussed. Existing pest control practices largely utilise control at the level of the individual. Much current research relates to population control procedures. The pesticide industry is concerned with innovations relating to the mode of action of conventional insecticides as well as to new ways of using chemicals to control insect populations. It is suggested the long term success of population control procedures depends as much on the provision of appropriate organisasuccess of population control procedures depends as much on the provision of appropriate organisational requirements as on solving the technical problems.Finally, the likely future couse of pest control is considered. It is suggested that over the next 10 years or more the major burden of pest control will continue to fall on the pesticide industry much as at present. The first innovations, over the period 5–15 years hence, are likely to concern conventional pesticides with novel modes of action. Population control procedures will gradually become established and this process will accelerate over the period 10–20 years hence and beyond. However, full benefit from such procedures will only accrue if organisatonal requirements have been met. 相似文献
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浅议生物农药取代化学农药 总被引：6，自引：1，他引：5
近年来，“生物农药”已经有了发展，但也存在一些问题，把活性成分为化学物质的植物农药，抗生素农药等视为“生物农药”，从实用角度看，似为不妥；泛透“生物农药”安全，无公害的，科学依据不足；世界环发大会（1992）提出，到2000年，“生物农药”用量要占农药60%的口号已化为泡影，因为它的依据不足，仅为一个政治号召。 相似文献
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景观生态规划:概念、内容、原则与模型 总被引：18，自引：0，他引：18
景观规划是景观生态学研究中一个重要的应用研究领域。本文通过国内外的景观生态规划方面研究文献的概括与分析，分别就其要概念内涵、研究内容、景观生态规划与设计的基本原则、主要景观生态规划模型进行了论述，进而对景观生态规划在我国的研究现状进行了评述，并在有关问题上提出了自己的看法。 相似文献
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1978年春,在新疆博湖从惊纹地老虎Agrotis exclamationis(Linné)(鳞翅目:夜蛾科)幼虫中发现一株病毒“Ae—02”,病毒颗粒体为卵形或卵圆形,大小为374～780×312～450nm,平均为578×412nm;病毒粒子杆状,两端钝圆,不弯曲或稍弯曲,大小为350～450×40～65nm,平均为395×50nm。该病毒对惊纹地老虎和黄地老虎A.segetum(Schiff.)幼虫致病力强。在日平均温度为24.2℃时,对1日龄惊纹地老虎幼虫感病19天后死亡率达96～100%;25天后10日龄幼虫死亡率达84～92%;对15日龄幼虫死亡率为73.96～80.96%。惊纹地老虎病毒“Ae—02”毒株,属杆状病毒科Baculoviridae,杆状病毒属Baculovirus,“B”亚组,定名为惊纹地老虎颗粒体病毒Agrotis excula-mationis granulosis virus,俗名鸣夜蛾颗粒体病毒,拉丁学名为Baculovirusexclamationis“B”,简称AeGV。 相似文献
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外来入侵植物猫爪藤概述 总被引：6，自引：0，他引：6
外来植物猫爪藤，早年曾作为观赏植物引入我国，目前已经被列为中国的外来入侵种。本文概述了国内外对猫爪藤的研究状况，简要介绍了猫爪藤的分类学特征和群落分布，论述了其生态特征和危害，指出了防治的困难及其可利用性。在南非，人工防治和化学防治的效果不大，因而引入吃叶片的龟甲科昆虫Charidotis auroguttata作为生物防治试剂。在澳大利亚，化学防治取得了一定的效果，但人们还是把目光转向生物防治。尽管人们对防治策略开展了不少研究，但是到现在为止，国外还没有任何一种清除猫爪藤的有效方法。猫爪藤在许多国家被作为民间药物。因此，应该全面深入地认识猫爪藤，采取防治和利用相结合的综合措施。 相似文献
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ABSTRACT Plant-associated microorganisms are critical to agricultural and food security and are key components in maintaining the balance of our ecosystems. Some of these diverse microbes, which include viruses, bacteria, oomycetes, fungi, and nematodes, cause plant diseases, whereas others prevent diseases or enhance plant growth. Despite their importance, we know little about them on a genomic level. To intervene in disease and understand the basis of biological control or symbiotic relationships, a concerted and coordinated genomic analysis of these microbes is essential. Genome analysis, in this context, refers to the structural and functional analysis of the microbe DNA including the genes, the proteins encoded by those genes, as well as noncoding sequences involved in genome dynamics and function. The ultimate emphasis is on understanding genomic functions involved in plant associations. Members of The American Phytopathological Society (APS) developed a prioritized list of plant-associated microbes for genome analysis. With this list as a foundation for discussions, a Workshop on Genomic Analysis of Plant-Associated Microorganisms was held in Washington, D.C., on 9 to 11 April 2002. The workshop was organized by the Public Policy Board of APS, and was funded by the Department of Energy (DOE), the National Science Foundation (NSF), U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS), and USDA-National Research Initiatives (USDA-NRI). The workshop included academic, industrial, and governmental experts from the genomics and microbial research communities and observers from the federal funding agencies. After reviewing current and near-term technologies, workshop participants proposed a comprehensive, international initiative to obtain the genomic information needed to understand these important microbes and their interactions with host plants and the environment. Specifically, the recommendations call for a 5-year, $500 million international public effort for genome analysis of plant-associated microbes. The goals are to (i) obtain genome sequence information for several representative groups of microbes; (ii) identify and determine function for the genes/proteins and other genomic elements involved in plant-microbe interactions; (iii) develop and implement standardized bioinformatic tools and a database system that is applicable across all microbes; and (iv) educate and train scientists with skills and knowledge of biological and computational sciences who will apply the information to the protection of our food sources and environment. 相似文献
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A ROOT ROT OF CHRYSANTHEMUMS 总被引：1，自引：1，他引：0