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二斑叶螨(又叫白蜘蛛)是一种重要的世界性害螨,是叶螨科中食性最广的一种.其寄主作物有800余种,包括蔬菜、玉米、棉花、果树、花卉及杂草等多种植物.因其繁殖扩散速度快,容易产生抗药性等特点,使得防治极其困难.以若螨、成螨聚集在果树叶片的背面刺吸汁液,使叶片呈灰白色或枯黄色细斑,严重时叶片干枯脱落,造成树势衰弱,产量降低.近年,二斑叶螨已经上升成为陕西蒲城梨园三大害螨之一.2009-2011年零星发生,危害较轻;2012-2014年迅速扩大蔓延,其中党睦、陈庄、贾曲、东杨等乡镇的部分园片偏重发生,给防治工作增加了更大的难度.根据2014年基数和今年气象条件预计,2015年二斑叶螨在我县梨园将中等偏重发生.笔者依据二斑叶螨在梨树上的发生危害特点提出防治措施,供梨农在生产中参考. 相似文献
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二斑叶螨和苹果全爪螨对药剂敏感性比较试验 总被引：5，自引：0，他引：5
苹果全瓜螨一直是北方苹果园的重要害螨,二斑叶螨近年来也迅速蔓延。在害螨的防治中,由于长年大量、频繁地使用化学农药．致使许多药剂防效下降或害螨已产生严重的抗药性。本文通过室内杀螨剂对二斑叶螨和苹果全爪螨的毒力测定,比较２种叶螨对药剂敏感性差异,对吝螨的防治具有一定的指导意义。１材料与方法 （１）试虫苹果全爪螨,采自泰山普照寺果园;二斑叶螨,采自岱岳区满庄镇菜园, （２）供试药剂１％齐墩螨素乳油;１５％哒螨灵乳油;２０％甲氰菊酯乳油;２０％三氯杀螨醉乳油;５７％克螨特乳油;２０％双甲眯乳油;１５％三哇… 相似文献
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二斑叶螨是世界性害螨，自20世纪90年代起，该螨在我国山东、辽宁、河北、陕西及甘肃等果产区发生危害，近年来危害日益严重，已成为果产区主要害螨。二斑叶螨具有繁殖力强、抗药性强、危害时间长、食性杂等特点，可危害果树、蔬菜、农田、林木、花卉及杂草等200多种植物，给防治带来一定难度。当前，市场上防治叶螨的药剂很多，为筛选出 相似文献
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二斑叶螨属蛛形纲,蜱螨亚纲,螨目,叶螨科,又名二点叶螨、白蜘蛛。二斑叶螨是一种几乎遍布于全世界的害螨,据中国农科院董慧芳等研究,在20世纪80年代以前,在我国没有该螨的分布,以往的很多记载均为误定。二斑叶螨可能是在20世纪 相似文献
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胶东地区果园叶螨类害虫演替动态与防治技术 总被引：1，自引：0，他引：1
<正>果园叶螨类害虫一直是胶东果园的重要靶标害虫,如苹果全爪螨(苹果红蜘蛛)Panonychus ulmi(Koch)、山楂叶螨Tetranychus viennensis Zacher、二斑叶螨T.urticae Koch、截形叶螨(Tetranychus truncatus Ehara),在蓬莱小门家和牟平酒馆处采到的样品与果苔螨(Bryobia rubrioculus(Scheuten))十分相像。 相似文献
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二斑叶螨 Tetranychusurticae koch是多食性重要害螨,广泛分布于世界各地。关于在我国的分布和为害,过去多与其近似种朱砂叶螨T cinna barinus和截形叶螨 T turncatus等相混淆。据笔者调查,近年来在我国甘肃、河北等地个别的果园,二斑叶螨相继发生和为害,并有进一步扩散和蔓延的趋势。 于1991年就温度因子对二斑叶螨生长发育及繁殖的影响进行了探讨,供试二班叶螨采自河北省昌黎果树所,在养虫室内用盆栽菜豆隔离饲养。 在室内不同温度条件下饲养观察结果表明。二斑叶螨的发育速度与温度呈正相关,在15℃、20℃、25℃和30℃条件下,完成一… 相似文献
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几种杀螨剂对二斑叶螨的防治效果 总被引：3，自引：0，他引：3
二斑叶螨（ＴｅｔｒａｎｙｃｈｕｓｕｒｔｉｃａｅＫｏｃｈ）又名二点叶螨,俗称白蜘蛛,属叶螨科叶螨属,主要危害棉花、果树、花卉等,属典型的杂食性害螨。１９９５年开始在黄河故道地区发现并迅速蔓延,１９９７年在我场果园大发生,由于该螨抗药性极强,目前在防治上... 相似文献
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Fruit cracking after rain limits the production of a number of crops, including some Ribes species. To gain a better understanding of the factors involved in cracking, fruit growth, deposition of the cuticular membrane (CM), water uptake and fruit cracking were studied in black currant (Ribes nigrum L. cv. Zema), gooseberry (Ribes uva-crispa L. cv. Rote Triumph), and jostaberry (Ribes nidigrolaria B. cv. Jostine). Fruit surface area and fresh mass increased continuously throughout development, whereas deposition of the CM was biphasic. CM mass per fruit increased rapidly up to 42, 41, and 49 days after full bloom (DAFB) in black currant, gooseberry, and jostaberry, respectively. Thereafter, CM mass per fruit remained constant in gooseberry and jostaberry or increased at a lower rate in black currant. The cessation of or reduced rate of CM deposition resulted in a decrease in CM mass per unit area in all berries. Elastic strain of the CM at maturity averaged 23.8% and 19.5% in gooseberry and jostaberry, respectively, and only 8.2% in black currant. Microcracks in the CM were observed first in gooseberry and jostaberry 64 DAFB, whereas there were no microcracks in black currant. Water uptake into mature detached berries was linear over 2 h of incubation. Rates of uptake were highest in gooseberry followed by black currant and jostaberry. Relative uptake was similar via the cut end of the pedicel (32.1%), the apex of the fruit (34.7%) and the fruit surface (33.2%). Rates of water uptake through the fruit surface were positively related to surface area. Average fruit water potential for black currant, gooseberry, and jostaberry was −2.14 ± 0.17, −1.24 ± 0.03, and −1.89 ± 0.20 MPa, while the permeability for osmotic water uptake was 7.7 ± 0.4 × 10−8, 5.2 ± 0.1 × 10−8, and 3.3 ± 0.3 × 10−8 m s−1. Incubating whole fruit in deionized water for 72 h resulted in more cracked jostaberries (94%) than black currants (74%) or gooseberries (50%). A comparison of our findings in Ribes berries with published data for the sweet cherry drupe revealed that the berries fitted the relationships established in sweet cherry among fruit growth, cuticle deposition, strain of the cuticle, microcracking, permeability for osmotic water uptake, frequency of stomata and cracking. The Ribes berries were less susceptible to cracking than sweet cherry. 相似文献
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Mortalin(mtHSP70/HSP75/Grp75/TRAP-1/PBP74) is an essential mitochondrial chaperone and is believed to regulate multiple cellular functions ranging from cell survival, cell proliferation, stress response, mitochondrial biogenesis and intracellular trafficking. Recent studies have shown that mortalin is relevant to the pathogenesis of Alzheimer's disease(AD) and Parkinson's disease(PD). Proteomic studies demonstrate the differential expression of mortalin not only in the models of AD or PD but also in PD human brains as compared to the controls. Mortalin seems to modulates the development of diseases through association with the critical molecules such as apoE, amyloid β-protein, amyloid precursor protein(APP) in AD, and α-synuclein, DJ-1, PINK1 in PD. Mortalin may regulate PD development via the pathways involving mitochondrial and proteasomal functions as well as oxidative stress. Furthermore, it is reported that mortalin participates in the pathological processes of several other neurological disorders, such as ischemic brain injury, absence seizure and Friedreich's ataxia(FRDA). 相似文献
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中国''''99昆明世界园艺博览会蔬菜瓜果园 总被引：1，自引：0，他引：1
蔬菜瓜果园作为中国’99昆明世界园艺博览会六大专题展园之一 ,占地 4 90 0ｍ2 。园内以农舍草屋为中心 ,通过瓜架、篱笆、草亭及蔬菜瓜果栽培 ,构出一幅农家乐园式的田园风光。另外 ,通过集中展示中国蔬菜瓜果的科技生产水平 ,丰富的资源优势 ,色彩缤纷、新奇别致的蔬菜瓜果品种 ,来突出本次世博会的主题“人与自然 ,和谐发展———迈向 2 1世纪” ,从而展现“蔬菜瓜果园艺是人类赖以生存的重要食源和艺术”为主题思想的蔬菜瓜果园内涵。 蔬菜瓜果园位于世博园主入口世博大道南侧 ,与盆景园、药草园相邻。在总体布局、栽培上充分运用园… 相似文献
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以杂种榛优良品系为试材,分析氮、磷、钾、钙与贮藏物质的相关性。结果表明:氮、磷、钾和钙与脂肪显著或极显著正相关。氮、磷和钙与蔗糖显著或极显著正相关,‘82-11’品系中的磷和钾与可溶性总糖显著或极显著正相关,‘84-237’品系中的钙与可溶性总糖显著正相关,‘84-402’品系中的磷素与可溶性总糖显著正相关。 相似文献
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江汉平原是国家优质粮食、优质棉花和双低油菜重要生产基地,也是湖北省西瓜主产区。种植西瓜对增加农民收入、丰富市场、发展农村经济、提高土地利用率具有重要作用。江汉平原西瓜生产的突出特点是间作套种,早在20世纪70年代就推广了“麦／／瓜-稻”这种水旱、粮经作物配套种植的优化模式．并获得原荆州地区科技进步二等奖。由于西瓜间作套种提高了单位面积的经济效益、 相似文献
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Growing a resilient landscape depends heavily on finding an appropriate match between the scales of demands on ecosystems by human societies and the scales at which ecosystems are capable of meeting these demands. While the dynamics of environmental change and ecosystem service provision form the basis of many landscape ecology studies, enhancing landscape resilience is, in many ways, a problem of establishing relevant institutions that act at appropriate scales to modify and moderate demand for ecosystem services and the resulting exploitation of ecosystems. It is also of central importance for landscape sustainability that institutions are flexible enough to adapt to changes in the external environment. The model provided by natural ecosystems suggests that it is only by encouraging and testing a diversity of approaches that we will be able to build landscapes that are resilient to future change. We advocate an approach to landscape planning that involves growing learning institutions on the one hand, and on the other, developing solutions to current problems through deliberate experimentation coupled with social learning processes. 相似文献
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Harold S. J. Zald Thomas A. Spies Manuela Huso Demetrios Gatziolis 《Landscape Ecology》2012,27(8):1197-1212
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors at multiple spatial scales. The purpose of this research was to quantify spatiotemporal patterns of meadow invasion; and how climate, larger landforms, topography, and overstory trees have interactively influenced tree invasion. We combined airborne Light Detection and Ranging (LiDAR) characterizations of landforms, topography, and overstory vegetation with historical climate, field measurements of snow depth, tree abundance, and tree ages to reconstruct spatial and temporal patterns of tree invasion over five decades in a subalpine meadow complex in the Oregon Cascade Range, USA. Proportion of meadow occupied by trees increased from 8?% in 1950 to 35?% in 2007. Larger landforms, topography, and tree canopies interactively mediated regional climatic controls of tree invasion by modifying depth and persistence of snow pack, while tree canopies also influenced seed source availability. Landscape context played an important role mediating snow depth and tree invasion; on glacial landforms tree invasion was negatively associated with spring snowfall, but on debris flows tree invasion was not associated with snow fall. The importance of snow, uncertain climate change impacts on snow, and mediation of snow by interacting and context dependent factors in complex mountain terrain poses substantial hurdles for understanding how these ecotones may respond to future climate conditions. 相似文献
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Spatial patterns of fire occurrence in Catalonia,NE, Spain 总被引：2，自引：0，他引：2
In this paper, we analyse spatial patterns of fire occurrence in Catalonia (NE Spain) during 1975–98. Fire scar maps, discriminated by means of 30–60 m resolution remote sensing imagery, have been used as a source of fire occurrence. We employ several visual or analytical approaches to interpret fire occurrence in this region, such as those of Minnich and Chou (1997), Ricotta et al. (2001) or Krummel et al. (1987). Crucial spatial patterns such as fire size distribution, fire frequency distribution, spots and residual vegetation islands are documented. In addition, several geographical layers were overlaid with burned area maps in order to determine interactions between fire occurrence and environmental parameters such as altitude, slope, solar radiation, and burned land cover. Assuming that fire occurrence is well determined by such a posteriori empirical factors we detect areas most prone to fire in this region and aim to enhance the local forest management and conservation plans. 相似文献
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Richard E. Toth 《Landscape Ecology》1988,1(4):193-201
A soft paradigm for landscape analysis is presented. This paradigm focuses on the analysis of function first, and then on structure. The objective is to determine which factors are operationally significant, how these factors bring about change, and how they define the spatial characteristics of landscapes. 相似文献