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[目的]测定敌敌畏毒土防治鼠妇的毒力效果。[方法]将80%的敌敌畏乳油按100、200、400、800和1 000倍五个配比配成毒土,测定其室内对普通球鼠妇的杀虫效果,利用SPSS统计分析出其LC50值。[结果]室内实验表明,随敌敌畏毒土配比的增高,即随敌敌畏乳油含量的下降,普通球鼠妇的平均死亡率明显降低,毒土配比为100倍,试虫平均死亡率为98.9%;毒土配比为200倍、400倍、800和1 000倍时,试虫平均死亡率为81.1%、73.3%、40.0%、33.3%。[结论]通过不同毒土配比的差异比较,表明400×毒土比较适合生产应用,80%敌敌畏乳油毒土配比的LC50为642.10倍。关键词毒力效果;敌敌畏毒土;鼠妇;防治 相似文献
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核型多角体病毒对斜纹夜蛾酚氧化酶活性及血淋巴黑化的影响 总被引:1,自引:0,他引:1
以斜纹夜蛾核型多角体病毒(SlNPV)为免疫刺激因子,观察SlNPV对斜纹夜蛾幼虫酚氧化酶活性及其血淋巴黑化的影响。结果表明:斜纹夜蛾幼虫感毒后,其血淋巴黑化率在感毒1d后开始逐渐下降,随着感毒时间推移和幼虫日龄增大,病毒抑制其黑化作用增强;在感毒后连续5d观察时间内,感毒幼虫血淋巴黑化率始终低于健康幼虫,且在感毒4~5d后达到显著水平;感毒幼虫体内及其血淋巴酚氧化酶活性在感毒后前3d都是逐渐上升而后逐渐下降;感毒幼虫体内酚氧化酶活性在感毒后前3d高于健康幼虫,在感毒4d后开始低于健康幼虫,且在感毒2、3、5d后均达到显著水平;与健康幼虫相比,感毒幼虫血淋巴酚氧化酶活性在感毒2d后开始明显增强,但感毒5d后急剧下降。 相似文献
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<正>为加强高毒农药监管,今年农业部在河北、浙江、江西、山东、陕西五省开展高毒农药定点经营试点。各地按照"统筹规划、合理布局、自愿申报、严格标准、程序公开、公正遴选"的原则,确定一批示范县和定点门店,实行高毒农药专柜销售、实名购买、电子档案、科学指导,建立高毒农药可追溯体系,逐步实现从生产、流通到使用的全程监管,探索建立高毒农药监管的长效机制。 相似文献
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茶藨生柱锈重寄生木霉产毒条件的优化 总被引:1,自引:0,他引:1
运用产毒培养基筛选、锈孢子诱导和正交试验对茶藨生柱锈重寄生木霉SS003菌株(rrichoderma atroviride)的产毒营养条件进行优化.结果表明,SS003在5种产毒培养基中均能产毒和生长,但Richard培养基更适合产毒培养,PD培养基则更适合菌丝生长;茶藨生柱锈的锈孢子对产毒具有一定抑制作用;SS003... 相似文献
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采集疑似鸭瘟病毒自然感染的病死番鸭的肝脾等组织,应用番鸭胚成纤维细胞(MDEF)进行病毒分离,通过对分离毒的血凝特性(HA)测定、间接免疫荧光试验(IFA)荧光定量PCR、PCR产物测序和动物回归试验等初步鉴定。结果显示:通过MDEF从疑似病料中分离到4株病毒(DPVfj1、DPVfj2、DPVfj3、DPVfj4),均不能凝集鸽红细胞;IFA结果排除了分离毒为鹅细小病毒、番鸭细小病毒、鸭呼肠孤病毒、鸭副粘病毒和禽坦布苏病毒;鸭瘟病毒荧光PCR试剂盒检测分离毒核酸均为鸭瘟阳性;鸭瘟病毒(JQ673560)gJ蛋白基因序列特异引物进行PCR扩增均为阳性,且PCR产物序列与鸭瘟病毒参考株gJ蛋白基因序列相似度均大于99%;动物回归试验显示,分离毒人工感染30日龄番鸭和同居感染5日龄雏番鸭均可复制出与自然感染一致的临床表现及病理变化,并能回收到病毒。上述结果表明4株分离毒均为鸭瘟病毒强毒株。 相似文献
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对五号病强弱毒在传代细胞上产生蚀斑的研究表明,强毒OK_5株大、中、小斑分别为8,5和2mm,且一般在接种后50h就能充分出斑,弱毒OM_2R_(39)株大、中、小斑分别为3.5,2和1mm,出斑时间在100h以后;用蚀斑测毒,强毒OK_5的蚀斑毒价高于弱毒OM_2R_(39)3.8倍。由此证明五号病强弱病毒有遗传本质的不同。 相似文献
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In China, a soil-borne virus causing a disease of winter wheat and associated with Polymyxa graminis, has been reported for many years and is now recognized as a new species, Chinese wheat mosaic virus (CWMV). Since the determination of its genomic sequence, more progress has been made in understanding its genomic structure and functions. Molecular and serological methods have been developed to help survey the distribution of the virus and to provide the basic information needed for disease forecasting and control. At present, the best countermeasure is cultivation of resistant wheat varieties. In addition, development and application of some auxiliary countermeasures, such as rotation of non-host crops, delayed seed-sowing, reasonable application of nitrogen fertilizer, and treatment of imported seeds with fungicides before sowing, may be helpful for controlling the disease. The viral distribution and damage, virion properties, genome organization and spontaneous mutation, temperature sensitivity, and disease management options are here reviewed and/or discussed to help in developing more cost-effective countermeasures to control the disease in the future. 相似文献
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目的 探讨湖南省早发冠心病(premature coronary heart disease,PCHD)患者冠脉病变程度与中医证素之间相关性。方法 对156例早发冠心病患者进行证素分类辨证分析。冠脉病变程度以狭窄程度表示,病变积分以Gensini积分计算,心功能分级采用Killip分级。结果 各证素组所占比例从高到低依次为痰浊 > 阴虚 > 血瘀 > 气虚 > 热蕴,各组间冠脉病变程度与证素无明显相关性,各组间心功能Killip分级无显著差异,各组Gensini积分气虚组病变积分较其他组高。结论 湖南地区早发冠心病以痰浊为主要证素,但含有气虚证素的早发冠心病一般较为严重。 相似文献
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Development,evaluation and application of a spectral knowledge base to detect yellow rust in winter wheat 总被引:1,自引:0,他引:1
Jingcheng Zhang Wenjiang Huang Jiangyuan Li Guijun Yang Juhua Luo Xiaohe Gu Jihua Wang 《Precision Agriculture》2011,12(5):716-731
In most cases, statistical models for monitoring the disease severity of yellow rust are based on hyperspectral information.
The high cost and limited cover of airborne hyperspectral data make it impossible to apply it to large scale monitoring. Furthermore,
the established models of disease detection cannot be used for most satellite images either because of the wide range of wavelengths
in multispectral images. To resolve this dilemma, this paper presents a novel approach by constructing a spectral knowledge
base (SKB) of diseased winter wheat plants, which takes the airborne images as a medium and links the disease severity with
band reflectance from environment and disaster reduction small satellite images (HJ-CCD) accordingly. Through a matching process
with a SKB, we estimated the disease severity with a disease index (DI) and degrees of disease severity. The proposed approach
was validated against both simulated data and field surveyed data. Estimates of DI (%) from simulated data were more accurate,
with a coefficient of determination (R
2) of 0.9 and normalized root mean square error (NRMSE) of 0.2. The overall accuracy of classification reached 0.8, with a
kappa coefficient of 0.7. Validation of the estimates against field measurements showed that there were some errors in the DI value
with the NRMSE close to 0.5. The result of the classification was more encouraging with an overall accuracy of 0.77 and a
kappa coefficient of 0.58. For the matching process, Mahalanobis distance performed better than the spectral angle (SA) in all
analyses in this study. The potential of SKB for monitoring the incidence and severity of yellow rust is illustrated in this
study. 相似文献
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Yu-qiang ZHAO Yan-li TIAN Li-min WANG Guo-min GENG Wen-jun ZHAO Bai-shi HU You-fu ZHAO 《农业科学学报》2019,18(4):815-820
Fire blight, caused by Erwinia amylovora, is a devastating disease of apples and pears, causing enormous economic losses around the world. The disease is indigenous to North America and has spread to more than 50 countries since its discovery in 1870s. Recent reports of the disease in China's neighboring countries, including South Korea, Kyrgyzstan, and Kazakhstan, pose great threat to the world's leading producer of apples and pears. This mini-review intends to provide an update on the disease, pathogen biology, epidemiology, and control. It will also provide some perspectives and suggestions for the apple and pear industry and growers in China, which will face the imminent threat of this devastating disease. 相似文献
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【目的】探讨林分因子、黄柏抗性生理指标与黄柏膏药病发生程度之间的相关性。【方法】采用踏查法进行调查,以树皮肿胀度代表含水量,采用考马斯亮蓝G250法测定蛋白质含量,氮蓝四唑光化还原法测定酶活性,硫代巴比妥酸比色法测定丙二醛含量。【结果】树龄大的黄柏,病情指数更高,阴坡比阳坡发病率高,树种组成单一的黄柏林更易发病。黄柏感病后,树皮含水量大大降低,树皮相对肿胀度与发病率、病情指数极显著负相关。3个样地健康黄柏防御酶活性均较高,感病黄柏中超氧化物歧化酶(SOD)活性波动较大,过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活性呈显著下降趋势,3种酶活性与病情指数为显著或极显著负相关。感病黄柏树皮中的可溶性蛋白和丙二醛含量在病害发生最严重时期显著升高。【结论】树龄、地形、树种组成等因子对黄柏膏药病的发生有显著影响;树皮含水量、防御酶(SOD、POD、PAL)活性、丙二醛含量等抗性生理指标受病害影响显著。 相似文献
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田间调查的结果表明,番茄早疫病在西藏的林芝地区温室发生严重。发病初期在5月上旬,发病高峰期在7~8月,这与该病发生需要高温、高湿相一致。一般晚熟品种较早熟品种病情轻。 相似文献