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1.
烟蚜属半翅目蚜科,是烟田的重要迁飞性害虫,成蚜和若蚜聚集于烟叶幼嫩部位,吸食植物汁液,滋生霉污病并传播烟草病毒病害,造成产量和质量损失.本文在湖北恩施地区选择烤烟田对烟叶从移栽至中部烟叶开始采收阶段的田间有翅烟蚜和无翅烟蚜的空间分布和发生动态进行调查,并通过地统计学方法分析其半变异函数特性,模拟其田间迁移模式.结果表明:恩施烟区有翅烟蚜种群动态为双峰曲线,烟叶移栽后第3周和烟叶打顶后第2周为发生高峰,呈现随机、聚集、随机、聚集、随机5步过程;无翅烟蚜种群动态为单峰曲线,烟叶打顶前为发生高峰,呈现随机、聚集、随机3步过程;人为因素和寄主特性对其种群密度影响较大;空间分布模拟插值图可以清晰反映出田间烟蚜的发生动态,结合Pearson相关分析发现,有翅蚜迁入高峰期,烟蚜种群数量小并高度集中,构成了田间烟蚜的虫口基数,是烟蚜防治的关键时期.  相似文献   

2.
烟蚜自然种群聚集与扩散趋势的初步研究   总被引:1,自引:0,他引:1  
李正跃  邓炜 《动物学研究》1993,14(4):313-317
本文采用空间格局分析方法,从烟草移载到烟叶采收,对烟蚜Myzus persicae在烟株和烟株上,中,下三个部位的聚集和扩散趋势,采用Mont Lolyd给出的方法,并结合Iwao的m-m回归分析法和m-m的改进模型进行判断分析。结果表明,六月下旬和七月中旬是烟蚜在烟株上的两个聚集高峰期。烟蚜在烟株不同部位的聚集和扩散趋势有所不同。整株烟株和上,中,下部烟蚜都呈聚集分布。分析结果对指导烟蚜防治有一  相似文献   

3.
为筛选出有效的长期预测因子,对江苏通州和江苏淮安褐飞虱前期迁入量与太平洋海温场遥相关时空分布分别进行了相关分析及其稳定性检验。结果表明: 与褐飞虱前期迁入量连续稳定显著相关的海温区,在空间上主要分布在中太平洋和南太平洋(72.4%),在时间上主要分布在前两年和前一年(82.7%)。分别分析褐飞虱前期迁入量与当年4-8月上旬各旬降水量、平均温度、当年1-8月500 hPa西太平洋副高月平均指数之间的两两相关关系,并比较这三者与前期太平洋海温场遥相关时空分布的异同。根据对两地的个例分析表明:前一冬春季赤道中东太平洋海温的变化引起当年6月副高面积指数的变化,影响江苏通州当年6月下旬降水,从而影响江苏通州褐飞虱的前期迁入量;前两年春夏季赤道中东太平洋海温的变化引起当年5月副高北界位置的变化,影响江苏淮安当年7月上旬降水,从而影响江苏淮安褐飞虱的前期迁入量。在此基础上,对褐飞虱前期迁入量与太平洋海温场遥相关的可能机制提出“海温→大气环流(副高)→气候→褐飞虱前期迁入"的一般假想模式。  相似文献   

4.
【目的】棉蚜Aphis gossypii和棉长管蚜Acyrthosiphon gossypii是棉花上的共存种,本文拟明确不同恒温条件下两种蚜虫单种和共存时的种群动态、有翅蚜发生及在棉株上的分布情况,探讨温度对两者种间竞争的作用。【方法】棉蚜、棉长管蚜单种、混合初始等蚜量设置,分别置于室内21、24和27℃恒温条件下,系统调查记录各处理种群数量、有翅蚜数量及在棉株上的分布,应用内禀增长率rm、空间分布情况、有翅蚜比例为竞争判别指标。【结果】棉蚜单种种群过程的rm均大于棉长管蚜,共存条件下一种对另一种蚜虫的rm均没有显著影响;棉蚜种群97%以上在叶片活动,棉长管蚜在叶片的比例为55%~75%;同一温度条件,两种共存不影响对方在棉花叶片和茎秆上的分布;棉蚜和棉长管蚜主要分布于棉花中上部。随温度升高,共存种群中棉蚜向棉株下部移动的比例增加,单种和共存种群棉长管蚜趋向于棉株上部移动。同一温度条件下,共存对棉蚜上下分布没有明显影响。21℃和27℃棉蚜的存在对棉长管蚜没有显著影响,但24℃时共存可使棉长管蚜在下部的比例明显增加;随温度的升高,棉蚜有翅蚜比例下降显著,而棉长管蚜无显著变化。【结论】适温范围内,两种蚜虫种间竞争的存在不影响彼此的内在繁殖能力,棉蚜比棉长管蚜具有更强的内在竞争能力;温度对棉蚜在竞争活动空间上的影响不明显,而对棉长管蚜的上下位置的选择有一定作用;种间竞争和种内竞争加速棉蚜有翅蚜的发生。  相似文献   

5.
玛绢金龟成虫在烟田的空间格局分析   总被引:4,自引:0,他引:4  
在烟株上玛绢金龟成虫的空间格局进行了测定。采用Taylor幂法则,Iwao聚集格局回归分析法和负二项概率模型来处理调查数据。结果显示:3种方法的聚集指数都表明玛绢金龟在烟株上的空间格局为聚集分布,Taylor幂法则拟合田间数据优于Iwao聚集格局回归分析法。  相似文献   

6.
不同农业景观结构对麦蚜种群动态的影响   总被引:4,自引:0,他引:4  
赵紫华  石云  贺达汉  杭佳  赵映书  王颖 《生态学报》2010,30(23):6380-6388
研究表明农业景观结构的复杂性与害虫种群发生强度关系密切,然而在不同农业景观结构下研究麦蚜的发生、种群及寄生蜂的变化还不多。设计了不同的麦田景观结构,调查研究了不同麦田景观结构对麦蚜种群的影响。在简单与复杂两种农业景观结构下,分析了不同种类麦蚜的入田时间、入田量、种群增长率、种群密度及寄生性天敌的多样性与寄生率。结果表明:景观结构对不同种类麦蚜影响不同,但复杂农业景观下麦蚜迁飞入田时间都要晚于简单农业景观(连片种植)下的入田时间,复杂农业景观下有翅蚜的迁入量显著低于简单景观下有翅蚜的迁入量,并且复杂农业景观下麦蚜种群增长速率高于简单农业景观下的增长速率。不同种类麦蚜对景观结构的不同反应可能与形态学与生活史特征有关,两种不同农业景观结构下寄生性天敌的多样性与寄生率无显著差异。复杂景观结构下的麦蚜有翅蚜低的迁入量、高的增长速率可能与生境高度破碎化有关,其中与温室大棚塑料白色反光有的很大的影响。生境破碎化影响了麦蚜对寄主植物寻找以及天敌对猎物的寻找效应。  相似文献   

7.
【目的】为了明确吸虫塔对麦长管蚜Sitobion avenae(Fabricius)迁飞活动监测效果的影响因素。【方法】采用回归分析和通径分析等方法,分析田间麦长管蚜数量与吸虫塔吸捕量的相关性,分析不同气象因素对吸虫塔中麦蚜吸捕数量的影响程度。【结果】结果显示,吸虫塔的有翅蚜吸捕量与田间麦长管蚜种群密度及有翅蚜数量存在显著的相关性,即田间麦长管蚜有翅成蚜数量对吸虫塔的吸捕量具有直接影响,而吸虫塔中麦长管蚜的吸捕量也直接反映田间有翅成蚜及种群动态的实际情况。另外,在廊坊地区,吸虫塔初期监测到的有翅麦长管蚜要比小麦田间发生的早几天。通过对吸虫塔中麦长管蚜有翅成蚜吸捕量与气象因素灰色关联度分析的结果表明,降雨天气对麦长管蚜的迁飞和种群动态具有突出的影响作用,可以造成麦长管蚜有翅成蚜迁入的"突增"和种群的"骤降";同时温度和湿度是两个影响麦长管蚜迁飞的重要因素;在麦长管蚜的迁入初期,温度对其迁飞影响最大;在大风天气,风速也会对麦长管蚜的迁入或飞翔活动产生较大影响。【结论】田间麦长管蚜发生数量与吸虫塔的吸捕量存在正相关;降雨、温度和风速是影响麦长管蚜迁飞活动的主要气象因素。  相似文献   

8.
烟田龟纹瓢虫的空间分布型及抽样技术   总被引:2,自引:1,他引:1  
对8块烟田的龟纹飘虫空间分布调查和分析结果表明,该虫空间分布符合负二项分布,均属聚集分布,聚集的原因主要是由环境因素所致,抽样方式以棋盘式抽样代表性最强。  相似文献   

9.
恩施烟区无翅桃蚜在烤烟田空间动态的地统计学分析   总被引:2,自引:0,他引:2  
恩施烟区是湖北省最大烟叶生产基地,桃蚜Myzuspercicae(Sulzer)是恩施烟叶最重要的害虫之一,桃蚜在田间的发生以及传播的病毒病害逐年加重,给烟业生产带来巨大损失。进一步了解桃蚜发生动态和空间分布规律,将提高对桃蚜的预测效果并为其综合防治提供理论依据。烟区和烟田之间的迁移以有翅蚜为主,田块内部的种群动态和发生规律,无翅桃蚜发挥着更加重要的作用。受寄主生理生化特性影响,不同烟叶生育期,桃蚜空间结构的差异需要进一步验证。经典的统计学方法以纯随机变量为基础,而昆虫种群的田间分布存在空间相关性,地学统计学承认空间相关性的存在,为区域化变量的空间分布分析提供新的理论和方法。在烟叶不同生育期进行无翅桃蚜的田间密度调查,运用地统计学的方法分析了其空间特征和发生动态,模拟了无翅桃蚜在烟叶不同生育期的田间分布图,并对无翅桃蚜在不同烟叶生育期田间分布格局的相关性进行了分析。结果表明:无翅桃蚜在烟叶苗期密度最小为(5.59±4.07)头/株,烟叶旺长期虫口密度最大为(14.5±9.6)头/株;种群密度变异系数均较大(0.6147-0.7281),表明其空间分布的不均匀性,并随密度的增大而减小,表明种群密度的增大一定程度上提高了种群结构的稳定性。烟叶苗期的种群分布曲线峰度最大,表现出更高的聚集性。无翅桃蚜在烟叶苗期的135°方向和团棵期的45。方向表现为随机分布。烟叶苗期的0°方向和45°方向可用线性有基台模型拟合,其他均可用球形+指数套合模型拟合,判断球形+指数套合模型是无翅桃蚜田间分布的主要模型,属于聚集型分布的范畴。块金值、基台值和变程均随田间虫口密度的增大而增大,苗期的随机程度(0.1905—0.7186)明显大于其他时期(0.0116—0.1620)。无翅桃蚜空间分布模拟图可以清晰地看出无翅桃蚜苗期迁移,旺长期后逐渐稳定的特性。无翅桃蚜的田间分布在烟叶苗期与团棵期无明显相关性,而团棵期与旺长期以及旺长期与成熟期显著相关,再次证明烟叶苗期到团棵期,无翅桃蚜的田间分布发生较大迁移,而团棵期以后基本定殖。烟叶苗期的无翅桃蚜高度聚集在少数烟株上,及早预防可以减少烟叶苗期虫口基数,有利于桃蚜种群数量的控制。首次将平面坐标系划分为4个方向,更加准确、全面地描述昆虫种群的空间分布特征。  相似文献   

10.
大量研究表明多样性的农业景观格局能够影响蚜虫及寄生蜂的分布。本文利用并设计了两种尺度的麦田农业景观格局,依据麦蚜种群发生特点,分为迁入期、增长期与高峰期三个时期,论述了不同尺度下农业景观元素对麦蚜及寄生蜂系统的影响,通过逐步回归筛选了不同时期麦蚜及寄生蜂分布的关键景观元素,最后通过CANOCO软件模拟了麦蚜及寄生蜂的分布排序格局。结果表明不同景观因子对麦蚜及寄生蜂种群影响不同,迁入期两种尺度下裸地最有利于两种有翅蚜的迁飞入田,塑料大棚对有翅蚜种群的入田有抑制作用。增长期草地与林地生境对麦蚜种群增长率促进最大,塑料大棚同样抑制了麦蚜的种群增长率;但塑料大棚、草地与林地对蚜茧蜂的种群增长率有促进作用,非麦类作物生境对蚜茧蜂种群增长率抑制作用最大;草地与林地有利于重寄生蜂的种群增长率;高峰期裸地比例大的农业景观下麦蚜的最大种群密度较大,草地与林地对蚜茧蜂与重寄生蜂的最大种群密度均有促进作用。两种尺度下的研究结果一致。不同麦物种的对不同景观元素反应与形态学与生活史特征有关,而且景观结构中特定的植物种类、非作物植物的密度与物候期都可能影响寄生蜂群落的多样性与功能。  相似文献   

11.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

12.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

13.
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.  相似文献   

14.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl (0.19), glutamate (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.  相似文献   

15.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.  相似文献   

16.
17.
The aim of this report has been to present results concerning analytical quality controls of Hg analysis of fish and sediment, analyses of Fe, Ca, total-P, K, pH, alkalinity, conductivity, colour and hardness (Ca + Mg) of lake water samples. Despite the fact that these are standard parameters in many regular water control programs, there are major differences in the reliability with which these parameters can be determined. The focus here is on an overall inter-laboratory comparison between the parameters. Six laboratories have been involved in the analysis. Selected results: pH gives the lowest (average) relative standard deviation (error), about 2 %; conductivity gives an error of about 5–7 %; alkalinity yields an average error of as much as 13–25 %, which is the largest among the parameters studied here; colour also gives a high error, 9–15 %; hardness gives a relative standard deviation of about 6–7 %. Of the other parameters (i. e., Hg, Fe, Ca and P), Hg gives the best reliability and Fe and P the lowest. To have knowledge of the reliability of the analytical data is of paramount importance in most control programs and research projects.  相似文献   

18.
We investigated the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, and Hf) and the effect of Ca on their uptake in carrots (Daucus carota cv. U.S. harumakigosun) by the radioactive multitracer technique. The experimental results suggested that Na, Mg, K, and Rb competed for the functional groups outside the cells in roots with Ca but not for the transporter-binding sites on the plasma membrrane of the root cortex cells. In contrast, Y, Ce, Pm, and Gd competed with Ca for the transporters on the plasma membrane. The selectivity, which was defined as the value obtained by dividing the concentration ratio of an elemental pair, K/Na, Rb/Na, Be/Sr, and Mg/Sr, in the presence of 0.2 and 2 ppm Ca by that of the corresponding elemental pair in the absence of Ca in the solution was estimated. The selectivity of K and Rb in roots was increased in the presence of Ca. The selectivity of Be in roots was not affected, whereas the selectivity of Mg was increased by Ca. These observations suggest that the presence of Ca in the uptake solution enhances the selectivity in the uptake of metabolically important elements against unwanted elements.  相似文献   

19.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.  相似文献   

20.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

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