星星草治理草原碱斑的效果与种植技术     

赵喜印  佟振宇 《草业科学》1992,9(5):61-62

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The effect of eradication of lice on the occurrence of the grain defect light flecks and spots on cattle hides.     

O Nafstad  H Gr?nst?l 《Acta veterinaria Scandinavica》2001,42(1):99-106

The influence of an eradication programme for lice on the prevalence of light flecks and spots on cattle hides was studied in 33 dairy cattle herds during a period of two and a half years. Lice were eradicated from the main group of herds after 9 to 12 months and the quality of the hides before and after treatment was compared. Hides from slaughtered animals were collected during the study period, tanned and examined with special emphasis on the occurrence of the grain damage light flecks and spots. The prevalence of hides without light flecks and spots increased from 24.2% before treatment to 61.6% after treatment. The prevalence of hides free from the damage increased significantly in all examined anatomical regions. The improvement in hide quality was most marked in the shoulders and neck region which corresponded to the major predilection site of cattle lice. The prevalence of hides with light flecks and spots started to decrease in the first period (2-40 days) after eradication. The changes after treatment suggested that most healing process took place over a period of about 4 months. The eradication programme eliminated the seasonal variation in the prevalence of light flecks and spots which was present before treatment.  相似文献   

Contribution to the taxonomy and pathogenicity of fungicolous Verticillium species. II. Pathogenicity     

Dr. A. van Zaayen  Dr. W. Gams 《European journal of plant pathology / European Foundation for Plant Pathology》1982,88(4):143-154

In recent years in the Netherlands a second mushroom species,Agaricus bitorquis, which prefers higher temperatures thanA. bisporus and is less susceptible to certain diseases, is often commercially grown.Verticillium fungicola var.fungicola, the causal agent of dry bubble, is responsible for considerable damage in crops ofA. bisporus. InA. bitorquis, however, dry bubble has hardly been noticed, but brown spots due toV. fungicola var.aleophilum resulted in inferior mushroom quality. The latter variety also caused brown spots ina. bisporus, but to a minor degree. In variety Les Miz 60 ofA. bisporus, however, it also induced fruit-body deformation in a way different from dry bubble. Verticillium psalliotae, isolated fromA. bitorquis in England, induced more confluent brown spots inA. bitorquis. In the netherlands, where moreA. bitorquis is grown than in other countries,V. psalliotae has not yet been encountered in crops ofA. bitorquis. V. psalliotae, which has a high temperature optimum for mycelial growth, likeV. fungicola var.aleophilum andA. bitorquis, did not infectA. bisporus in our trials.Artificial infection ofA. bisporus orA. bitorquis could not be accomplished with the following related and/or fungicolous fungi:Verticillium lamellicola, V. fungicola var.flavidum, V. biguttatum, Nectriopsis tubariicola, Acremonium crotocinigenum andAphanocladium album.Samenvatting Vooral in Nederland wordt sinds een aantal jaren naastAgaricus bisporus ook de warmteminnende champignonsoortAgaricus bitorquis geteeld, die minder vatbaar is voor bepaalde ziekten. TerwijlVerticillium fungicola varfungicola in de teelt vanA. bisporus droge mollen en daardoor veel schade veroorzaakt, komen in de teelt vanA. bitorquis geen droge mollen voor maar wel bruine vlekken, die tot kwaliteitsverlies en dus schade leiden. De vlekken bleken veroorzaakt te worden doorV. fungicola var.aleophilum. Deze schimmel veroorzaakte ook inA. bisporus bruine vlekken, hoewel in minder ernstige mate, maar in het ras Les Miz 60 vanA. bisporus bovendien misvormde champignons, die wel op droge mollen leken, maar daaraan niet gelijk waren.OokV. psalliotae, in Engeland geïsoleerd vanA. bitorquis met vlekken, veroorzaakte wat meer samenvloeiende, bruine vlekken inA. bitorquis. In Nederland, waar meerA. bitorquis geteeld wordt dan in andere landen, isV. psalliotae nog niet aangetroffen in teelten vanA. bitorquis. InA. bisporus kon geen kunstmatige infectie worden verkregen metV. psalliotae, die net alsV. fungicola var.aleophilum enA. bitorquis warmteminnend genoemd zou kunnen worden.Met de volgendeVerticillium-achtige of van paddestoelen geïsoleerde schimmels kon evenmin op kunstmatige wijze een infectie worden opgeroepen inA. bisporus ofA. bitorquis: Verticillium lamellicola, V. fungicola var.flavidum, V. biguttatum, Nectriopsis tubariicola, Acremonium crotocinigenum enAphanocladium album.  相似文献   

城市风景类风景名胜区建设模式初探——以广州白云山风景名胜区为例     

李宜斌  邓卓迪 《广东园林》2015,(3):28-32

结合对广州白云山风景名胜区规划和建设的调研和观察结果,从布局、功能、配套设施、生态结构4个方面加以分析,试图总结并归纳城市风景类风景名胜区规划建设的特点和内在规律,为相关风景区规划与建设提供参考。  相似文献   

Birefringence analysis of collagen supraorganization in cat corneas with tropical keratopathy     

Ana L. S. N. Tinasi  Camila P. B. Silveira  Cristiane S. Honsho  José L. Laus  Marcela Aldrovani 《Veterinary ophthalmology》2023,26(5):398-406

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高标准农田建设区域划定与项目区选址研究   总被引：6，自引：0，他引：6  

孙茜  牛海鹏  雷国平  赵玉领  张捍卫  张合兵 《农业机械学报》2016,47(12):337-346

以河南省新郑市为例,基于GIS和改进突变级数模型相结合的方法测度高标准农田建设的适宜性和空间稳定性指数,并以耦合协调度模型统筹适宜性和空间稳定性,从而明确高标准农田建设的区域,在此基础上通过冷热点分析遴选高标准农田建设项目区。结果表明,研究区较为适宜开展高标准农田建设,优先建设区、重点建设区、全面整治建设区和不宜建设区的面积分别为27 004.83、17 040.40、4 361.16、5 761.55 hm2。其中优先建设区应大力发展特色优质安全高效现代农业,重点建设区以整治项目为依托提升利用效率和效益,全面整治建设区以优化耕地布局和提升潜力为主,不宜建设区应注重修复提升地力、增强防灾抗灾能力。通过冷热点分析高标准农田建设的适宜性和空间稳定性耦合协调度在空间上的联系模式,实现了快速识别高标准农田建设项目区,结合研究区实际遴选了10个高标准农田建设项目区。同时,基于障碍度模型诊断识别各项目区的主要障碍因素,从而有针对性地指导各项目区有序开展高标准农田建设活动。  相似文献   

江西婺源旅游景区蜘蛛多样性的研究     

陈连水  袁凤辉  饶军  周谷春 《安徽农业科学》2010,38(24):13240-13245

调查主要集中在婺源县境内的7个代表性旅游景区中,从土壤、地表、树表、岩表、水表等获取样本后经分离提取,共获得蜘蛛标本530份,经鉴定共计18科51属87种,其中江西新记录种8种,未确定种12种。此外,还对婺源旅游景区蜘蛛资源名录与区系分布、蜘蛛群落结构、蜘蛛多样性等进行了分析和探讨。  相似文献   

基于G-MRF模型的玉米叶斑病害图像的分割   总被引：3，自引：0，他引：3  

赖军臣  汤秀娟  谢瑞芝  白中英  李少昆 《中国农业科学》2010,43(7):1363-1369

【目的】图像分割是作物病害自动识别系统实现的难点之一,前人研究大多采用基于阈值或聚类的分割算法,方法简单、易于实现,但分割精度较低。本文引入高斯模型的Markov随机场分割模型(G-MRF),对玉米叶部病斑图像进行分割试验,以期提高分割精度。【方法】在VC6.0下实现了G-MRF分割模型,G-MRF既利用了图像像素的灰度信息,又通过像素类别标记的Gibbs光滑先验概率引入了图像的空间信息,是能较好地分割含有噪声图像的算法。采用该算法对大斑病、小斑病、灰斑病和弯孢菌叶斑病等4种主要玉米叶部病害的图像进行了分割测试,并与基于阈值和基于Gauss模型的分割算法进行比较。【结果】基于G-MRF分割模型的分割,目标区域的一致性和边缘的清晰方面明显好于基于阈值和Gauss模型的分割算法,其平均正确分类率达96.35%,分别较基于阈值和基于Gauss模型的分割算法高出3.75%和4.03%,差异达到显著水平。【结论】基于G-MRF模型的分割算法鲁棒性高,能够有效地将病斑区域从叶片部分离,分割正确分类率达96.35%,可用于玉米叶斑类病害图像的分割。  相似文献   

基于转移矩阵和信息熵的地类变化分析——以钟山风景区为例     

温小荣  蒋丽秀  薛冬冬  林国忠  谢小杰  郑勇  佘光辉 《西南林学院学报》2014,(1):40-44,51

基于南京市钟山风景区1987-2002年森林资源二类调查数据,采用转移矩阵和地统计方法综合分析其地类变化。结果表明：1987-2002年,钟山风景区针叶林和非林地减少,阔叶林和针阔混交林地增加;600m幅度下的钟山风景区地类信息熵值空间格局层次感较强,1987年钟山风景区地类景观按信息熵值可分为高值区和低值区2个区域,其中高值区域主要分布于明孝陵景区、中山陵景区的中部,低值区域主要集中在自然景观区和山岳景观区;2002年钟山风景区地类景观按信息熵值可分为3个较高值区域和1个较低值区域,高值区域分布于明孝陵景区、中山陵景区的中部以及自然景区北部,低值区域位于自然风景区南部;1987-2002年,研究区地类信息熵低值区域在减少,高值区域在增加,但总体呈上升的变化趋势,一定程度说明土地利用结构向多样性发展,均衡性越来越强。  相似文献   

番鸭呼肠孤病毒的分离与鉴定   总被引：12，自引：0，他引：12  

吴宝成  陈家祥  姚金水  陈枝华  陈文列  李国平  曾显成 《福建农林大学学报(自然科学版)》2001,30(2):227-230

从番鸭肝“白点病”患鸭的肝脾匀浆中分离到 7个病毒分离株 .在电镜下观察到病毒粒子呈球形 ,无囊膜 ,有可见的双层衣壳结构 ,外壳直径 75nm,内核直径 50 nm;病毒核酸型为 RNA;不凝集鸡、鸭、兔、豚鼠红细胞 ,与禽呼肠孤病毒有一定的抗原相关性 ;对番鸭胚和鸡胚成纤维细胞可致感染细胞圆缩、融合 ,出现多核细胞和巨细胞 ,胞浆内有近核包涵体 ;试验感染 1日龄敏感雏番鸭死亡率达 10 0 % ,临床及病理变化与自然感染发病的番鸭基本一致 ,并可回收到该病毒 .结果表明 ,目前国内流行的番鸭肝“白点病”病原为呼肠孤病毒科正呼肠孤病毒属番鸭呼肠孤病毒  相似文献