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应用Leslie矩阵对布氏田鼠种群数量的模拟分析 总被引：2，自引：0，他引：2
采用Leslie矩阵对内蒙古太仆寺旗草原的布氏田鼠作了种群动态模拟分析.结果表明:①该模型数值模拟的准确率达到87.7%.②矩阵特征值λ既表达了在调查时段种群达到稳定增长状态的周限增长率,又可作为衡量种群变动趋势的指标:当λ＞1.232时布氏田鼠种群处于上升期,当λ趋于1.232时种群处于高峰期,当λ＜1时种群处于下降期.③不同增长期的年龄结构与繁殖率的差异显著,在种群上升期,幼鼠比例明显高于高峰期和下降期.④在上升期,繁殖率为关键因子;在高峰期和下降期的关键因子是存活率. 相似文献
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基于亲景度-市场竞争态矩阵模型的新疆入境市场分析 总被引：2，自引：1，他引：1
在评价旅游偏好和市场竞争态的基础上,提出了亲景度-市场竞争态矩阵模型,使用该模型对新疆入境旅游市场进行了初步的分析,研究结果显示:独联体为新疆入境市场的一级市场,日本、韩国、美国为代表的周边国家和北美国家为二级市场,欧洲客源国为三级市场;而新疆入境市场客源国总体分布偏离理想状态。该模型不仅可以反映客源国(地)在某个区域的分布状况,而且可以反映该市场的分级情况,同时还可以反映该市场发展中存在的问题。希望该模型可以为旅游管理部门和决策者提供有益的帮助,为旅游市场分析提供一种新的方法。 相似文献
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质谱法在食品样本农药残留分析中的应用进展 总被引：4，自引：1，他引：3
质谱法(Mass spectrometry,MS)是当前农药残留分析中的主导检测技术。对气相色谱-质谱法(GC-MS)、气相色谱-串联质谱法(GC-MS/MS)、液相色谱-串联质谱法(LC-MS/MS)和飞行时间质谱法(time-of-flight mass spectrometry,TOF-MS)在食品样本农药残留分析中的应用进行了综述,重点对质谱技术在国内外多残留分析方法研究中的应用进展进行了总结和归纳,简要比较了质谱分析时常用的几种样品前处理技术的优缺点及其适用性,展望了质谱法在农药残留分析研究领域的发展前景。 相似文献
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The basic reproduction number, R0, is defined as the total number of infections arising from one newly infected individual introduced into a healthy (disease-free) host population. R0 is widely used in ecology and animal and human epidemiology, but has received far less attention in the plant pathology literature. Although the calculation of R0 in simple systems is straightforward, the calculation in complex situations is challenging. A very generic framework exists in the mathematical and biomathematical literature, which is difficult to interpret and apply in specific cases. In this paper we describe a special case of this general framework involving the use of matrix population models. Leading by example, we explain the existing mathematical literature on this subject in such a way that plant pathologists can apply the method for a wide range of pathosystems. 相似文献
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核基质结合区对马铃薯Y病毒全长非翻译CP基因介导抗病性的影响 总被引：3，自引：0，他引：3
为探索核基质结合区(matrix attachment regions,MARs)对RNA介导的病毒抗性的影响,我们将从烟草中克隆到的核基质结合区TM2构建在包含马铃薯Y病毒全长非翻译CP基因的植物表达载体pRPVYCPN的表达盒的两侧,构建了植物表达载体pRTM2CPNTM2。采用农杆菌介导基因转化法,将表达载体pRPVYCPN和pRTM2CPNTM2转入烟草品种NC89中,分别获得了144株和344株转基因烟草。抗病性检测发现,核基质结合区的存在能明显提高RNA介导抗性的产生效率。在含MARs转基因植株中,抗病植株的比率为15.1%,而不含核基质结合区的转基因植株的抗病比率则为8.3%。这一研究结果对抗病毒植物的分子育种和转基因表达调控有指导意义。 相似文献
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A matrix model of the life cycle of Salsola australis was constructed, based on population ecology data collected from the district of Lake Grace, Western Australia. The model was used to assess potential control strategies for this summer annual weed within the Western Australian broad acre grain cropping system. The population growth rate (λ) of S. australis in the absence of weed control strategies was 1.49 and was virtually unaffected by the dormant seedbank. However, λ increased to 8.21 if it was assumed that a constant number of seed immigrated into the area in question from neighbouring populations of S. australis , through farm-scale seed dispersal. As a result, effective weed management depended on reducing seed dispersal. The model determined that burning all senesced, mobile plants in late autumn, combined with herbicide control of the largest cohorts of S. australis in summer and autumn, reduced population growth rate to 0.79. This control strategy resulted in a 66.1% chance of the population becoming extinct over 25 years. Management strategies are proposed based on the results of the models and further research is required to validate their effectiveness and practicality in the field. 相似文献
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煤矸石主要物理特性及在栽培基质中应用的可行性分析 总被引：1，自引：0，他引：1
针对煤矿区煤矸石堆积,污染环境,堵塞河道,易造成地质安全等问题,谋求将煤矸石用于栽培基质的主要物料和低产土壤的改良剂。基于煤矸石在栽培基质中应用的可行性为主要研究目标,分别以采自陕西彬县、神木煤矸石为材料,研究了煤矸石的比重、斥水特性及改良措施与效果,结果表明:彬县和神木两地的煤矸石比重分别为1.89 g·cm-3和2.06 g·cm-3;神木煤矸石具有轻微斥水性,掺混6.31%以上的农田耕层土壤就能达到消除斥水性的目的;而彬县煤矸石具有严重斥水性,需用0.2%的湿润剂溶液喷洒煤矸石,就能达到消除斥水性的障碍,且效果较为持久。由此得出结论是,就煤矸石的物理性状而言,尽管存在着不同的斥水性障碍,但通过一定的改良,就可具备在栽培基质中使用的可行性。 相似文献
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Kanako Inoue Tomoko Suzuki Kenichi Ikeda Shan Jiang Naoki Hosogi Gang-Su Hyong Sizuka Hida Taku Yamada Pyoyun Park 《Journal of General Plant Pathology》2007,73(6):388-398
Spores and infection structures such as germ tubes and appressoria of Magnaporthe oryzae, the fungus causing blast disease of wheat, produced an extracellular matrix (ECM) on the surfaces of host leaves during
fungal differentiation. The chemical components and function of the ECM were studied to understand the pathological roles
using two immunological techniques and ECM-digesting enzymes. The ECM was characterized by fibrous and amorphous materials,
located in the spaces between fungal cell walls and plant cuticles. Immunohistochemical and immunoelectron microscopy suggested
that ECM includes components positively reacted with antibodies of four animal cell adhesion factors (collagen VI, vitronectin,
fibronectin and laminin) and an animal integrin α3. ECM, incubated on a cellulose membrane, was rapidly digested by matrix
metalloproteinases (collagenase and gelatinase B), resulting in the detachment of most infection structures from membrane
surfaces. Both ultrastructural observation and immunological responses showed that more ECM was located at the appressoria
than at the spores and germ tubes. This result suggested that appressoria needed a powerful adhesion force for aggressive
action of penetration pegs into plant cuticles.
An erratum to this article can be found at 相似文献
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基底硬度是调控植物病原真菌侵染结构形成的重要物理信号。为探讨基底硬度对玉米大斑病菌(Setosphaeria turcica)侵染能力的影响,本研究利用不同硬度的PDA培养基进行模拟试验,并在不同叶龄的玉米叶片上进一步验证,结果表明,基底硬度越大,气生菌丝越少,菌丝分枝越多;硬基底上,病菌的分生孢子产量高,是软基底和适中硬度基底上的29.93和6.82倍,且硬基底上病菌附着胞形成率显著高于软基底。研究发现,在硬基底上生长的大斑病菌菌落颜色较深,菌丝中黑色素含量高。利用实时荧光定量PCR技术分析病菌黑色素合成途径中相关基因的表达情况,发现在硬基底上StMR1、StPKS、St4HNR、StSCD、St3HNR、StLAC1、StLAC2和StLAC4基因的相对表达量均高于软基底。上述结果说明,基底硬度影响了病菌形态结构的发育,导致了与侵染相关的黑色素含量的变化和侵染结构的形成,研究结果为探究植物病原真菌的侵染机制和病害防控提供了理论依据。 相似文献
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探讨油页岩有机碳矿化分解过程、有机碳组分变化特征以及环境因素作用规律可为评价油页岩在栽培基质中应用的可行性提供科学依据.试验在室内控制温度和水分条件下,分析了洗盐和未洗盐油页岩有机碳矿化动态变化特征.结果表明:油页岩基质在60 d培养期间,温度升高10℃使未洗盐基质总矿化量分别增加2%～28%(100%田间持水量)、2%～22%(80%田间持水量)和1%～15%(60%田间持水量);洗盐基质则分别增加2%～17%(100%田间持水量)、1%～5%(80%田间持水量)和7%～14%(60%田间持水量).将第60 d基质中活性有机碳含量进行回归分析,发现两种不同供试油页岩活性有机碳含量与温度和水分之间均呈正相关关系;未洗盐油页岩活性有机碳含量与温度和水分间相关性不显著,而洗盐后油页岩活性有机碳含量与温度和水分之间相关性显著(P=0.0214).用一级动力学方程拟合油页岩基质有机碳矿化动态得到未洗盐基质分解速率常数最大达1.2×10-3/d,洗盐基质其分解速率常数介于0.5×10-3～0.7×10-3/d.油页岩在长达60 d的培养过程中表现为有机碳持续分解、活性有机碳递增,证实其在基质栽培中的应用将对养分持续供给和维护作物根系生理活性发挥重要作用. 相似文献
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基质干扰是免疫法检测食品中农药残留时经常碰到的问题。以胡萝卜、菠菜、香蕉、梨、稻米和花生等为试材,研究了不同农产品基质对酶联免疫分析法(ELISA)检测三唑磷的影响。结果表明:不同农产品基质对ELISA检测的干扰机制不同,香蕉主要是抑制了辣根过氧化物酶的活性,菠菜、梨和稻米则主要是干扰了抗原和抗体的结合反应,胡萝卜和花生不仅抑制酶的活性,同时还干扰了抗原和抗体的结合反应。将这些农产品的磷酸盐缓冲液(PBS)(含2.5%甲醇)提取液用含有质量分数为0.3%的脱脂奶粉、0.1%的乙二胺四乙酸(EDTA)和含2.5%甲醇的PBS稀释10倍,在12000r/min下离心10min,即可消除其对ELISA检测的干扰。研究结果表明, ELISA法是可用于农产品中三唑磷残留检测的一种简单、快速、有效的方法。 相似文献
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The enhancement of Spodoptera litura (F.) nucleopolyhedrovirus (SlNPV) activity using the chitin synthesis inhibitor chlorfluazuron was investigated. When tested against fifth-instar S. litura larvae, chlorfluazuron produced synergistic effects at doses of 0.05 and 0.025 microg per insect, and additive effects at doses of 0.1 and 0.2 microg. Furthermore, the time required for SlNPV to kill larvae was significantly reduced by chlorfluazuron at all doses tested. The activity and killing speed of Autographa californica (Spey) nucleopolyhedrovirus (AcMNPV) against third-instar Spodoptera exigua (Hübner) larvae were similarly improved by chlorfluazuron at a dose of 0.05 microg per larva. Furthermore, the growth of S. exigua was significantly retarded by chlorfluazuron. Environmental scanning electron microscopy (ESEM) showed that the peritrophic matrices (PMs) of S. litura exposed to chlorfluazuron alone, or the combination treatment, were markedly disrupted. Obvious ruptures on the outer surfaces of the PM were observed, which potentially facilitated the passage of virions through the matrix. 相似文献
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冷藏温度、基质和时间对智利小植绥螨存活和生殖的影响 总被引：1，自引：0，他引：1
智利小植绥螨是叶螨属害螨的一种重要捕食性天敌,为发挥其控害效能,本研究在4℃和8℃两个温度下测试了叶片+叶螨、蛭石+叶螨和蛭石3种冷藏基质以及不同冷藏时间对智利小植绥螨存活和生殖的影响。结果表明:冷藏温度、基质和时间均对智利小植绥螨冷藏存活率有显著影响。冷藏5～15d时,在8℃下每种基质中的存活率均大于或等于4℃下的存活率,而冷藏20～40d时相反。用蛭石基质及蛭石+叶螨基质在4℃条件下冷藏35～40d和在8℃条件下冷藏25～40d的存活率均较叶片+叶螨基质有显著优势。在每个温度及每种基质内,智利小植绥螨冷藏存活率均随冷藏时间的延长而呈下降趋势。冷藏温度和冷藏时间对冷藏后智利小植绥螨一周内产卵量有显著影响。除了10d和15d处理,在4℃条件下智利小植绥螨冷藏后1周产卵量要高于8℃,特别是在冷藏20d后。在4℃条件下,冷藏5d和10d后的智利小植绥螨1周产卵量高于冷藏15d后产卵量;而在8℃条件下,冷藏10d和15d后智利小植绥螨1周产卵量高于其他冷藏时间段产卵量。总之,用蛭石作基质冷藏智利小植绥螨不但效果较好,而且较为经济适用,适宜在4℃条件下进行长期冷藏,有利于延长货架期。 相似文献
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The extracellular matrix (ECM) released by conidia ofColletotrichum graminicolawhen incubated on artificial hydrophobic substrata was investigated. Time-course experiments revealed that proteins and carbohydrates were released in the ECM of both ungerminated and germinated conidia. Stains for protein and carbohydrate revealed that part of the ECM remained attached to the substratum after the fungus had been removed. The ECM isolated from substrata where ungerminated conidia had adhered and from substrata where germinated conidia had adhered exhibited the same profiles when analysed by SDS-PAGE for proteins and glycoproteins and by HPLC for carbohydrate analysis. The ECM was found to be composed of glycoproteins with a molecular weight of around 200 kDa. Deglycosylation of the isolated ECM material resulted in the release of a protein with a molecular weight of approx. 116 kDa, indicating that the original protein was extensively glycosylated. Carbohydrate analysis demonstrated that mannose was the predominant sugar. That the ECM remained attached to the surface of the hydrophobic substrata suggests that it has a role in adhesion. 相似文献
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应用正交试验法研究了黄板悬挂高度、黄板形状、黄板距温室出口距离、黄板距北墙距离4个因素对黄板诱杀3种温室西葫芦害虫的影响。结果表明:4个因素对诱杀温室白粉虱都具有显著、极显著影响,黄板悬挂高度和黄板距出口距离对诱杀美洲斑潜蝇有显著影响;黄板距北墙距离对诱杀有翅瓜蚜具有极显著影响。黄板诱杀害虫的4因素组合为黄板高出植株0.2 m、平板形、距出口91 m、距北墙距离0.7 m时诱杀虫量最大。 相似文献