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基于功能平衡假说的玉米光合产物分配动态模拟 总被引:2,自引:0,他引:2
基于中国气象局沈阳大气环境研究所锦州农田生态系统定位观测站2004-2008年玉米各器官(根、茎和叶)生物量及相应环境因子的连续动态观测资料,检验了Friedlingstein模型在站点与日尺度上的适用性,并发展了基于施肥、土壤温度和土壤有效水分系数的玉米农田土壤有效养分系数模型,建立了基于功能平衡假说的日尺度的玉米光合产物的分配模型结果表明:与Friedlingstein模型相比,本文所建的玉米光合产物分配模型能更好地模拟玉米光合产物分配动态,为准确模拟日尺度的玉米农田生态系统生产力提供了技术支持. 相似文献
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植物的生长和发育离不开养分,其中所需的矿质营养主要来自根系的吸收。根系在供应植株地上部养分的同时,它还受到地上部养分需求的调节。因此植物根系和地上部之间保持着密切的联系,这种联系就是通过植物体内的养分循环来实现。植物体内的养分循环是指根系吸收的矿质营养,经木质部运输到地上部,其中一部分养分又经韧皮部返回根系的过程,即矿质营养经历了一个完整的循环过程:根系→木质部→地上部→韧皮部→根系。上述由地上部返回到根中的养分不能被根系完全利用,其中一部分又可经木质部再次运到地上部分,这一过程称为养分的再循环。根据矿… 相似文献
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在\"绿色植物与生物圈中的碳-氧平衡\"一节教学中,以光合作用重要概念为统摄,为学生创设真实的实验情境,帮助学生通过动手实践和积极思考,运用稳态与平衡观、结构与功能观相关知识,建立知识体系,并体现所学知识应用于解释和指导生活实际问题的价值,全方位落实核心素养中生命观念、科学思维、科学探究、社会责任四维素养目标. 相似文献
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目前对森林生物多样性维持机制的研究主要集中在检验地上生物的多度丰富度等内容,物种之间的交互作用及地下真菌是否影响生物多样性的维持在很大程度上还是未知的。探讨土壤真菌的作用及植物-土壤反馈在植物生长过程中的作用有重要意义。该研究以吉林蛟河针阔混交林中4个常见树种为研究对象,利用杀菌剂处理及不同树种幼苗的栽种控制实验来检验Janzen-Connell假说,计算生物反馈及特异性反馈,并依据高通量测序方法测定土壤真菌多样性,检验不同处理组间差异性。利用方差分解分析(VPA)分析两种反馈的幼苗生物量与树种本身、真菌功能类型及土壤元素间的关系。结果表明,土壤杀菌处理并未显著影响生物反馈,同物种土壤的幼苗生物反馈未表现出显著的距离制约效应。异种物种土壤并未显著提高水曲柳(Fraxinus mandshurica)幼苗的特异性反馈。此外, VPA结果表明,影响植物-土壤反馈最大的因素是物种本身特性,土壤和真菌的影响大小因反馈类型而异。该研究揭示了温带针阔混交林中植物-土壤反馈的影响因素,同时反映出温带森林不同树种的Janzen-Connell效应存在较大的变异性,为更好地研究物种间相互作用与其内在调控... 相似文献
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正物竞天择,适者生存。生物的生存都需要适应环境的变化,这对于植物来讲尤其如此,因为扎根于大地的植物并不能像动物那样通过远离或逃避实现趋利避害。在长期的进化过程中,植物已形成复杂而精细的调控机制以达到整体的协调,保证植物正常生长发育并适应各种环境的变化。作为地球生态系统的最大贡献者,地表生机盎然的植被给生态 相似文献
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外来植物入侵已成为严重的环境和社会问题,了解外来植物的入侵机制是有效控制其入侵的前提。生物阻抗假说认为,入侵地本地植物群落中的许多生物因子及生物过程能够抵御外来植物入侵。但关于群落抵抗外来种入侵的主要机制,目前还没有确定的结论。本文综述了群落中物种功能特征的多样性以及与外来种功能特征的相似度、植物与动物、植物与植物以及植物与土壤微生物间的相互作用等因素对外来植物入侵的影响,以及以前研究存在的不足。未来研究应该注重不同条件下植物与植物间的相互作用;不同竞争强度下,植物与食草动物的相互作用;植物、动物及土壤微生物三者之间的相互作用对外来植物入侵的影响。这些研究不仅能够丰富和完善入侵生态学理论,而且对于预测外来植物未来的扩散范围,合理有效地管理生态系统,防止外来植物入侵,保护本地生物多样性具有重要的实际意义。 相似文献
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为探究氮添加对濒危植物东北红豆杉幼苗生长-防御权衡的影响,为该物种的保护工作提供理论依据,本研究以东北红豆杉4年生幼苗为对象,进行了3种氮源(硫酸铵、硝酸铵和硝酸钾)和4个施氮量(30、60、90、120 kg N·hm-2·a-1)的氮添加实验。结果表明:(1)东北红豆杉幼苗的苗高增长量、地径增长量和总生物量随施氮量增加显著增加,施氮量超过90 kg N·hm-2·a-1后地径增长量和总生物量开始下降,施氮处理的幼苗根冠比显著低于对照组,但在不同施氮量下无显著差异;(2)净光合速率(Pn)和气孔导度在氮添加处理后显著提高,在施氮量为90 kg N·hm-2·a-1时达峰值,胞间CO2浓度与Pn的变化方向相反,说明氮添加可以缓解植物的非气孔限制;(3)黄酮类化合物含量在施氮后呈现先增高后降低的趋势,施氮量30 kg N·hm-2·a-1为转折点;(... 相似文献
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学者们利用林木枝条改良土壤方面已做了大量研究, 但林木枝条不同施用方式对土壤养分特别是微量元素的影响鲜见报道。以宁夏银川腹部沙地土壤为研究对象, 以当地杨树(Populus alba)枝条为土壤改良材料, 设置了土表覆盖粉碎的杨树枝条(CM)、土表覆盖未粉碎的杨树枝条(BM)、土壤中添加质量分数为5%的粉碎杨树枝条同时土表覆盖未粉碎杨树枝条(CI+BM)及土壤中分别添加质量分数为2%、5%、8%和11%的粉碎杨树枝条, 以无任何添加或覆盖枝条的土壤为对照(CK)。试验采用嵌入土壤中的PVC管模拟土壤自然环境且种植了春小麦, 在春小麦抽穗期测定了土壤养分及植物生长状况。研究结果显示, 与对照相比, 所有施用林木枝条处理均显著降低了土壤碱解氮含量(p < 0.05), 而且所有施用林木枝条处理亦均具有降低土壤有效铜含量的趋势。其他元素变化不同于土壤碱解氮和有效铜, 即所有添加处理具有增加土壤有效磷、速效钾、有效锰、有效铁和有效锌含量的趋势, 而所有覆盖处理却具有降低这些元素含量的趋势。此外, 杨树枝条覆盖及添加总体上对春小麦的生长均具有促进作用, 以CM和CI+BM效果最为显著(p < 0.05), 但春小麦生长会随着土壤中枝条添加比例的增加呈现出先促进后被抑制的趋势, 总体上以5%的添加比例最佳。然而, 相关分析结果表明, 林木枝条的长期施用均可能会对植物的生长产生营养元素相对匮乏的情况。 相似文献
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植物光合作用固定下来的能量沿食物链首先流向相邻营养级的植食性动物。植物-植食性动物相互关系是自然界中最普遍、最重要的一种种间关系, 是食物网理论的基础与核心。该文从植食性动物对植物个体、种群和群落特征的影响, 以及植物在个体、种群和群落3个水平上对植食性动物的防御机制与策略两方面, 综述了当前植物-植食性动物相互关系的研究进展。植食性动物的采食, 可以显著改变植物个体或种群的生长、繁殖和存活率, 植物种群的变化则进一步反馈于植物群落组成和多样性特征。相应地, 植物在个体、种群和群落水平形成了一系列的防御机制, 其中在个体和种群水平以化学与物理防御为主, 而群落水平则是通过影响动物的行为或天敌而实现的。该文对相关领域的重要假说和理论进行了介绍、比较。最后, 该文提出了植物-植食性动物相互关系研究的未来发展趋势。随着全球变化和人类活动对自然系统干扰的加剧, 在不同的时空尺度上探索这些干扰如何影响动植物关系, 以及这些影响如何反馈于生态系统的结构、功能和稳定性, 不但有重要的理论意义, 也将为未来制定合理的生态系统管理政策提供实际支撑。 相似文献
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Lauren J. Brzozowski Michael A. Gore Anurag A. Agrawal Michael Mazourek 《Plant, cell & environment》2020,43(11):2812-2825
Crop domestication and improvement often concurrently affect plant resistance to pests and production of secondary metabolites, creating challenges for isolating the ecological implications of selection for specific metabolites. Cucurbitacins are bitter triterpenoids with extreme phenotypic differences between Cucurbitaceae lineages, yet we lack integrated models of herbivore preference, cucurbitacin accumulation, and underlying genetic mechanisms. In Cucurbita pepo, we dissected the effect of cotyledon cucurbitacins on preference of a specialist insect pest (Acalymma vittatum) for multiple tissues, assessed genetic loci underlying cucurbitacin accumulation in diverse germplasm and a biparental F2 population (from a cross between two independent domesticates), and characterized quantitative associations between gene expression and metabolites during seedling development. Acalymma vittatum affinity for cotyledons is mediated by cucurbitacins, but other traits contribute to whole-plant resistance. Cotyledon cucurbitacin accumulation was associated with population structure, and our genetic mapping identified a single locus, Bi-4, containing genes relevant to transport and regulation – not biosynthesis – that diverged between lineages. These candidate genes were expressed during seedling development, most prominently a putative secondary metabolite transporter. Taken together, these findings support the testable hypothesis that breeding for plant resistance to insects involves targeting genes for regulation and transport of defensive metabolites, in addition to core biosynthesis genes. 相似文献
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Joshua S. Lynn;Jason D. Fridley;Vigdis Vandvik; 《Ecography》2023,2023(4):e06114
Herbivory rates have classically been hypothesized to decrease from the tropics towards higher latitudes because the more benign abiotic conditions in tropical systems foster greater ecosystem complexity including greater intensity of biotic interactions. However, attempts to quantify latitudinal patterns of herbivory often fail to support this hypothesis. While biases have been offered as explanations for null results, here, we argue that framing the question of latitudinal variation in herbivory around nutrient and energetic constraints of insect herbivores and plants may provide mechanistic explanations of latitudinal herbivory patterns. As a case study, we focused on sodium as an uncoupled nutrient between herbivore and plant communities: sodium is a key limiting micronutrient for herbivore neural and muscular development while present at orders of magnitude lower concentrations in plants. We compared sodium deposition with latitude, mean annual temperature (MAT) and actual evapotranspiration (measure of primary productivity, AET) in their ability to predict consumed percentage leaf area from published datasets. Leaf percent herbivory increased with sodium deposition and MAT and decreased with latitude but was unrelated to AET. Sodium had comparable effect size and predictive ability to either MAT or latitude. Additionally, herbivory was highest in locales with both high sodium deposition and high MAT. Our hypothesis that geographic variation in herbivory is driven by an interaction of unrestrictive temperature environments (high MAT) and limiting nutrient supply to herbivores (high sodium deposition) was strongly supported. We propose that greater generality, predictability and theoretical development on geographic variation in herbivory will arise from a refocus on the biophysical constraints (e.g. productivity, micronutrient availability, leaf mass consumed) that ultimately control consumer interactions rather than latitude per se. This refocus is likely to open new hypotheses for the evolution of defense syndromes across plant populations and communities based on the specific geography of limiting nutrients. 相似文献
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Regulation of secondary metabolism by the carbon-nitrogen status in tobacco: nitrate inhibits large sectors of phenylpropanoid metabolism 总被引:1,自引:0,他引:1
Fritz C Palacios-Rojas N Feil R Stitt M 《The Plant journal : for cell and molecular biology》2006,46(4):533-548
Interactions between nitrogen and carbon metabolism modulate many aspects of the metabolism, physiology and development of plants. This paper investigates the contribution of nitrate and nitrogen metabolism to the regulation of phenylpropanoid and nicotine synthesis. Wild-type tobacco was grown on 12 or 0.2 mm nitrate and compared with a nitrate reductase-deficient mutant [Nia30(145)] growing on 12 mm nitrate. Nitrate-deficient wild-type plants accumulate high levels of a range of phenylpropanoids including chlorogenic acid, contain high levels of rutin, are highly lignified, but contain less nicotine than nitrogen-replete wild-type tobacco. Nia30(145) resembles nitrate-deficient wild-type plants with respect to the levels of amino acids, but accumulates large amounts of nitrate. The levels of phenylpropanoids, rutin and lignin resemble those in nitrogen-replete wild-type plants, whereas the level of nicotine resembles that in nitrate-deficient wild-type plants. Expression arrays and real time RT-PCR revealed that a set of genes required for phenylpropanoid metabolism including PAL, 4CL and HQT are induced in nitrogen-deficient wild-type plants but not in Nia30(145). It is concluded that nitrogen deficiency leads to a marked shift from the nitrogen-containing alkaloid nicotine to carbon-rich phenylpropanoids. The stimulation of phenylpropanoid metabolism is triggered by changes of nitrate, rather than downstream nitrogen metabolites, and is mediated by induction of a set of enzymes in the early steps of the phenylpropanoid biosynthetic pathway. 相似文献
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依据嵌套分层设计原理制定野外调查取样方案,以药用资源植物短葶飞蓬不同产地93个自然种群310份植株样品的灯盏乙素和咖啡酸酯含量的嵌套方差分析,探讨次生代谢有效成分含量在产区间的空间变化。结果表明:短葶飞蓬有效成分含量存在空间差异,最低含量产区的总咖啡酸酯和灯盏乙素含量分别只是最高含量产区的52.1%和41.8%,但不与产地间的空间距离远近完全一致;同一产地短葶飞蓬总咖啡酸酯和灯盏乙素含量有一定的年际差异,但高含量产地与低含量产地是相对稳定的;作为优质药材的基本产地单元,自然地理区划单元比行政区划单元更科学;短葶飞蓬总咖啡酸酯和灯盏乙素含量与植株含N量呈极显著负相关,符合\"碳/氮营养平衡假说\"的预测,但植株含N量的变化只能解释短葶飞蓬总咖啡酸酯和灯盏乙素含量不同产区间约30%的变异。植物药材有效成分含量的空间变化是药用植物地区间遗传变异和生长地环境生态因子变化共同作用的结果,用自然地理区划单元为产地单元更客观。确定药材的\"优质产地\"可作为保障药材有效性的科学管理途径之一。 相似文献
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We present a theoretical analysis that considers the phenotypic trait of compensatory growth ability in a context of population dynamics. Our model depicts a system of three interactors: herbivores and two different plant types referred to as ordinary and compensating. The compensating plant type has the ability to increase its intrinsic rate of biomass increase as a response to damage. This compensatory growth ability is maintained at the expense of a reduced growth rate in the absence of damage, where the ordinary plant type has the higher growth rate. Analysis of this system suggests that, even though a compensatory capacity of this kind will not imply an increase in equilibrium plant density, it will give a competitive advantage in relation to other plants, in the presence of a sufficiently efficient herbivore. Invasion of compensating plants into a population of non-compensating plants is facilitated by a high compensatory growth ability and a high intrinsic rate of plant biomass increase. Conversely, an ordinary plant can invade and outcompete a compensating plant when the herbivore is characterised by a relatively low attack rate, and/or when plant intrinsic growth rate is decreased. 相似文献
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美丽镰刀(Fusarium mairei)是一分离自南方红豆杉(Taxus chinensis var.mairei)的产紫杉醇内生真菌,用B5培养基培养6 d,去菌尘幺后制得美丽镰刀菌培养液,并从中提取其胞外多糖.研究了4%(V/V)美丽镰刀菌培养液及4%(W/V)胞外多糖两种处理,对东北红豆杉(T.cuspidata)悬浮细胞防御反应及紫杉醇合成的影响.结果表明:两种处理均能诱导东北红豆杉细胞的防御反应.但美丽镰刀菌培养液的影响明显大于胞外多特(P<0.05).另外,两种处理均可促进东北红豆杉细胞紫杉醇的合成与释放.美丽镰刀菌培养液处理得到的紫杉醇与其释放率分别是对照的2.5倍8.8倍,而胞外多糖处理得到的紫杉醇与其释放率则分别是对照的1.5倍与3倍. 相似文献
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Gillor O Carmeli S Rahamim Y Fishelson Z Ilan M 《Marine biotechnology (New York, N.Y.)》2000,2(3):213-223
The location of latrunculin B, the major toxin of the Red Sea sponge Negombata magnifica, was revealed using specific antibodies. Antibodies from rabbits immunized with a conjugate of latrunculin B with keyhole
limpet hemocyanin (KLH) were purified over a latrunculin B–Sepharose affinity column. Analysis of immunohistochemical and
immunogold-stained sponge sections, using light and transmission electron microscopy, revealed latrunculin B labeling mostly
beneath the sponge cortex at the border between the external (ectosome) and internal (endosome) layers (ectosome-endosome
border). The endosome was less labeled than the border. Immunogold localization revealed latrunculin B in the sponge cells
but not in its prokaryotic symbionts. Archeocytes and choanocytes were significantly more labeled than other cells. The antibodies
primarily labeled membrane-limited vacuoles within archeocytes and choanocytes that are perhaps latrunculin B secretory or
storage vesicles. Peripheral latrunculin B may have a role in defense against external epibionts, predators, and competitors.
Received December 21, 1999; accepted March 5, 2000. 相似文献