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71.
江西百合病害调查与鉴定   总被引:12,自引:0,他引:12  
根据1990~1996年的系统调查和鉴定研究,明确了江西百合病害有26种,其中真菌病害16种,细菌性病害3种,病毒病害2种,线虫病害1种,生理性病害3种,病因未明的1种。本文描述了26种病害的症状、病原物、发生及分布情况。  相似文献   
72.
灰色动态模型群法在河流水质预测中的应用初探   总被引:5,自引:1,他引:5  
在对原始数据序列对数变换的基础上,依据灰色系统理论,构造了由6个GM(1,1)模型组成的灰色动态模型群,并用于淮河干流枯水期氨氮浓度变化趋势预测。研究表明,灰色动态模型群法能够充分利用近期水质资料信息预测水质变化趋势;相对单个GM(1,1)模型,灰色动态模型群法能有效改善随机波动数据序列的拟合效果,提高预测精度。  相似文献   
73.
A 28-day study was conducted to assess the dynamic of blood feeding by Rhipicephalus sanguineus ticks on dogs treated or not with a novel topical combination of fipronil, amitraz and (S)-methoprene. Dogs were infested weekly through exposure to ticks in crates for 4 h. Ticks were then counted in the crates at 2 h and 4 h post dog exposure. Ticks were also counted and removed from the dogs at 2 h, 4 h, 6 h, 12 h and 24 h post tick exposure. The inhibition of blood feeding was assessed by both tick quantification and designing and performing a quantitative PCR (qPCR) to detect the canine hydroxymethylbilane synthase (HMBS) gene in ticks. The percentage of repellency sensu lato based on the ticks collected in crates at 2 h varied from 4.7% at day 28 to 48.3% at day 7. The immediate mortality rate of the ticks expelled at 2 h varied from 1.5% at day 21 to 31.7% at day 7. The efficacy calculation showed that the acaricidal combination started to kill ticks in as little as 2 h. The average efficacy reached 90.0% at 12 h post crate challenges and 100% at 24 h post exposure in crates. The inclusion of an internal amplification control was used to ensure that no significant template-derived PCR inhibition (≤6.2%) affected the overall results. The reduction of blood feeding was significant at 4 h (>80.0%) and >99.0% at 24 h post tick exposure in the crate. The high repellency rate and the lethal efficacy of CERTIFECT® resulted in significantly fewer live attached ticks, consequently reducing blood intake and fluid exchanges.  相似文献   
74.
[目的]研究鱿鱼加工废弃物鱼酱油发酵过程中的生物胺含量变化。[方法]利用高效液相色谱-柱后衍生-荧光检测法研究了鱿鱼加工废弃物鱼酱油中酪胺、尸胺、组胺、精胺、亚精胺、胍丁胺和腐胺7种生物胺含量在发酵过程中的变化。[结果]鱼酱油中的7种生物胺得到了很好的分离和测定,平均回收率较好,为88.6%~111.7%,相对标准偏差RSD小于10%。鱿鱼加工废弃物鱼酱油发酵过程中7种生物胺的变化规律:酪胺含量随发酵时间的延长增加较快,腐胺次之,组胺含量增加较少,尸胺、胍丁胺、精胺、亚精胺含量在发酵过程中变化很小。发酵30d得到的鱿鱼加工废弃物低盐鱼酱油中酪胺、腐胺、组胺、尸胺、胍丁胺、精胺、亚精胺含量分别为(20.75±0.84)、(8.95±0.55)、(3.37±0.27)、(0.32±0.07)、(0.14±0.02)、(0.67±0.02)、(0.69±0.03)mg/L,其与日本鱿鱼鱼酱油各种生物胺的含量比例相似。[结论]为鱿鱼加工废弃物低盐鱼酱油的生产提供技术资料。  相似文献   
75.
基于高光谱成像的水稻穗瘟病害程度分级方法   总被引:3,自引:3,他引:3  
为了快速、准确地进行水稻穗瘟病害程度分级,以实现水稻品种抗性评价或精准的田间化学防治,该研究提出了一种光谱词袋(bag of spectrum words,Bo SW)模型分析方法,分析稻穗的高光谱图像,自动评判穗瘟病害程度。首先,稠密规整地将高光谱图像分割成小立方格,计算每个立方格像素的平均全波段包络矢量,用K-Means算法聚类形成典型光谱包络词典。词典中光谱包络"词"(word)用作高光谱图像表达的"基",直方图统计各光谱"词"在高光谱图像样本中的出现频度,形成光谱图像的词袋表达。采用Hyper SIS-VNIR-QE光谱成像仪获取田间采集的170株稻穗样本高光谱图像,用Bo SW方法生成其词袋表达;植保专家根据病害程度类别确定光谱图像样本标签。随机选择2/3"词袋表达-病害程度等级标签"数据对构成训练集,采用卡方-支持矢量机(chi-square support vector machine,Chi-SVM)分类算法建立穗瘟病害程度分级模型。余下的1/3样本构成测试集,测试穗瘟病害等级模型的预测性能,分类识别精度为94.72%,高于主成分分析(principle component analysis,PCA)、敏感波段选择等传统光谱分析方法,其识别精度分别为83.83%和79.83%。该研究提高了穗瘟病分级的自动化程度和准确率,也可为其他病害分级检测提供参考。  相似文献   
76.
为揭示上向流曝气生物滤池中有机氮沿程转化规律及其微生物特性,优化滤池的设计与运行,以有机氮废水为处理对象,在水力负荷0.329~0.50 5m3/(m2?h)、气水比4-5:1、沿程DO 3.0~5.85 mg/L、不加任何有机碳源的情况下,研究氮元素沿程转化规律。结果表明:曝气生物滤池内有机氮氨化与硝化同步进行,90%以上的溶解性有机氮(DON)转化为NO3-N;滤池沿程各段对于TKN的降解进程(TKN→NH3-N)与NH3-N的硝化进程(NH3-N→NO2--N→NO3--N)一致;微生物总量沿水流方向呈逐渐递减趋势;生物耗氧速率(OUR)沿程逐渐减小,OUR数量级为101 mg/(g?h)。该研究可为硝化滤池的设计提供理论依据以及滤池运行参数的优化提供技术支持。  相似文献   
77.
Heritage apple (Malus domestica Borkh. hybrids) and pear (Pyrus communis L. hybrid) trees grow in villages throughout Terceira Island, Azores, Portugal. Some of these pears have different names but similar morphology. The objective of this study was to determine synonymy, homology, and phylogeny of apples and pears from Terceira and to examine potential relationships of the island pears with standard apples and pears of Portuguese or American descent. Nine apple microsatellite markers were used to determine genetic relationships. Distance- and parsimony-based cluster analysis grouped these genotypes into separate apple and pear clades. The Terceira apples were divided into two clades: the maçā and the reineta-reinette. Among the 17 heritage apple genotypes, seven unique accessions were identified and four groups of synonyms, or possibly clones, were detected including: ‘Reineta Agosto’ and ‘Reineta Verde’ from Altares; ‘Reineta Castanha’ and ‘Reineta Verde Miuda’; ‘Maçā Pêra,’ ‘Maçā Calhau’, ‘Pêro Branco’ from Salga and from Terra-Chā and ‘Maçā Marmelo’; and the five genotypes ‘Maçā Sao Joao’, ‘Malápio Rosa’, ‘Maçā Gaspar’, ‘Maçā Branca’ and ‘Maçā Pato’. In addition, two homonyms were detected. ‘Pêro Vermelho’ from Terra Chā was a separate genotype from a tree from Doze Ribeiras of the same name, but Pêro Branco from Terra Chā appears to be a clone that can be distinguished by an additional allele at CH1F07a from a tree with that name from Salga. One pair of apple clones, ‘Reineta Agosto’ and ‘Reineta Verde’ from Altares appear to be derived from an unreduced gamete of ‘Golden Delicious.’ Another apple genotype ‘Maçā Acida’ could be a sibling of the ‘Maçā Pêra’ clonal group. Other tested standard apples from the US genebank were unrelated to Terceira genotypes. Of the seven heritage pears, five unique genotypes and one pair of synonyms were detected. ‘Pêra Papo Pintassilgo’ from Raminho and ‘Pêra Vermelha’ from the nursery of Serviço de Desenvolvimento Agario da Terceira (SDAT) were synonyms. ‘Passans du Portugal’ was related to ‘Pêra Cabaca’ but other standard pears from the US genebank were unrelated to Terceira genotypes. Future studies will include additional apple and pear cultivars from other Islands of the Azores and continental Portugal, and wild Asian species to further explore genetic relationships.  相似文献   
78.
水杨酸对采后桃果实脂氧合酶及相关指标的影响   总被引:5,自引:0,他引:5  
水杨酸 (salicylicacid ,SA)是一种植物体内产生的简单酚类化合物 ,广泛存在于高等植物中。已发现 ,外源施用SA可诱导某些植物开花和产热 ,诱导烟草和黄瓜等植物对病毒、真菌及细菌等病害的抗性 ,Raskin( 1 992 )提出SA可以被看作是一种新的植物内源激素 ,其作用和机制受到人们的关注。外源SA处理对园艺产品采后的作用研究还较少 ,仍有许多问题尚待探讨。本试验以 2个不同品种的桃果实为试材 ,研究了SA处理后果肉组织脂氧合酶活性以及其他相关指标的变化 ,并测定了果肉的硬度 ,为进一步探讨桃果实采后成熟衰老机制 ,改进现有贮藏方式提…  相似文献   
79.
根据饲料企业现状和发展趋势,综合饲料企业的物流管理,构建饲料企业的进销存管理信息系统,并引入地理信息系统,通过对空间数据的统计和分析,帮助决策企业运作政策。  相似文献   
80.
Infection of groundnut leaves with the early leaf spot pathogen Cercospora arachidicola leads to a marked increase in extracellular 1,3-β-glucanase activity, limited to the infected tissue. Three isoforms of low molecular weight and extreme pI values, typical of pathogenesis-related proteins, were induced. These β-glucanases, when acting together, were capable of degrading the pathogen cell wall in vitro. Glucanases from homogenates of infected leaf tissue were partially purified by ion-exchange chromatography to give enzymes with molecular weights of 35, 32 and 20 kDa and pI values of 3·8, 3·6 and > 9, respectively. They were electrophoretically identical to the β-glucanases found in the intercellular washing fluid. Treatment of groundnut plants with 200 μM mercuric chloride induced the accumulation of identical extracellular β-glucanases. During the course of the infection an increase in peroxidase activity was also observed, but chitinase activity remained more or less constant.  相似文献   
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