二氧化碳浓度升高或有助于提高蚜虫取食效率

<正>大气CO2浓度升高不仅加剧了全球气候变化,还改变了动植物的生长发育过程。其中,对C3植物最重要的影响是增加了光合作用,并降低气孔导度。而植物气孔导度的降低导致植物蒸腾作用降低,水分利用率增加,对蚜虫这类取食植物韧皮部汁液的刺吸式口器昆虫来说,寄主植物保持相对高的水势和膨压对蚜虫被动取食、获取植物汁     

玉米叶片气孔特征及气体交换过程对气候变暖的响应

气孔是植物叶片表面控制大气与植物间气体交换的孔状结构,对于生态系统碳、水循环过程的调节起着非常重要的作用。本文利用典型农田生态系统实验增温平台,研究了未来气候变暖对玉米叶片的气孔特征(包括气孔频度、气孔开口大小和形状以及气孔分布格局)和气体交换过程的影响。结果表明:(1)尽管增温并没有改变气孔密度(P0.05),但却由于表皮细胞数目的减少导致气孔指数显著增加12%(P0.05);(2)增温使气孔开口的长度显著减小18%(P0.01),宽度增加26%(P0.01),面积和周长分别增加31%(P0.01)和13%(P0.05);(3)实验增温还使单个气孔之间最近邻域的平均距离显著增加,表明气孔在玉米叶片上的分布变得更加均匀;(4)增温导致玉米叶片的净光合反应速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)分别增加52%(P0.05)、163%(P0.001)和81%(P0.05);与此相反,玉米叶片的暗呼吸速率(Rd)却显著降低24%(P0.01)。增温没有对细胞间CO2浓度(Ci)和水分利用效率(WUE)产生显著的影响(P0.05)。本研究结果表明,未来全球气候变暖可能通过改变玉米叶片的气孔频度、气孔开口大小和形状及其在叶片上的空间分布格局来改变其气体交换过程。     

单、双子叶植物气孔发育调控差异研究进展

作为植物与外界进行气体(如CO_2和水蒸气)交换的门户,气孔分布于植物茎、叶、果实和种子等器官的表皮上。植物通过调节气孔的开闭、大小和数目来控制气体的出入以适应环境。植物气孔类型多样,目前,最为典型的有两种类型,即双子叶植物的肾形气孔和单子叶植物的哑铃形气孔。从结构上讲,肾形气孔比哑铃形气孔少了一对副卫细胞,从进化角度讲,后者比前者更为进化。最近的研究工作揭示了控制气孔发育的主要关键基因以及环境信号调控气孔发育的基本途径。本研究主要从单、双子叶植物气孔的进化、发育、调控等方面阐述气孔发育及其调控机理的研究进展。     

日掌握控制植物气孔开张技术可增强植物光合作用

<正>日本名古屋大学近日发表一份公报称,其教授木下俊则率领的研究小组通过基因操作,扩大植物表皮上的气孔,使植物吸收更多二氧化碳,增强光合作用,植物产量也随之增加。木下俊则称,这是世界上首次掌握控制植物气孔开张的技术,将有助于增加农作物产量、扩大生物燃料生产等,还可为减排二氧化碳作贡献。     

植物蒸腾作用高速率之原因

摘要：植物蒸腾作用是植物最重要的生理活动之一,阐明植物蒸腾作用高速率的原因在农业方面有着重要意义。基于植物气孔结构,运用气象学、栽培学、高等数学、热学等学科相关理论,阐明了植物气孔蒸腾高速率的原因,即巨大的蒸发面积、较高的微环境温度、较大的气孔内外气压差等三因素,再此基础上,进一步阐明植物蒸腾作用高速率的原因,即叶面积指数和气孔下腔的特殊结构增大了蒸发面积、水分供应充足。气孔下腔有巨大的蒸发面积、较高的微环境温度、较大的气孔内外气压差、大的叶面积指数、充足的水分供应是植物蒸腾作用高速率的主要原因。     

利用丛枝菌根真菌(AMF)提高植物抗旱性的研究进展

丛枝菌根是分布最广泛的一类内生菌根,它可以促进植物对水分的吸收和利用,提高植物的抗旱能力。丛枝菌根真菌可以通过以下几个方面增强植物抗旱性:通过菌丝增加植物对土壤水分的吸收;改善植物的磷营养及其他矿质元素营养;能显著提高蒸腾速率和气孔导度;干旱条件下降低植株叶片水势、永久凋萎点、叶片饱和亏、气孔阻力和恢复时间;改变激素平衡。     

丛枝菌根真菌(AMF)提高植物抗旱性的研究进展

丛枝菌根是分布最广泛的一类内生菌根,它可以促进植物对水分的吸收和利用,提高植物的抗旱能力。丛枝菌根真菌可以通过以下几个方面增强植物抗旱性：通过菌丝增加植物对土壤水分的吸收;改善植物的磷营养及其他矿质元素营养;能显著提高蒸腾速率和气孔导度;干旱条件下降低植株叶片水势、永久凋萎点、叶片饱和亏、气孔阻力和恢复时间;改变激素平衡。     

中科院微生物所揭示气孔在植物免疫中的新功能

<正>气孔是由一对保卫细胞构成的植物叶表皮上的开孔,可响应环境因子刺激控制植物气体交换和水分蒸腾。作为植物表面的天然开孔,气孔也是许多病原菌入侵的通道。然而,植物可以主动关闭气孔来阻止病原菌的入侵,这一抗病过程被称为气孔免疫。但气孔在植物,特别是单子叶植物中是否还以其他     

中科院植物所等在生长素调控气孔发育研究中取得新进展

<正>气孔是植物表皮的特殊结构,在调节植物与外界气体和水分交换过程中发挥着重要作用,直接影响了植物光合和蒸腾两个植物基本生理进程。气孔是原表皮细胞经过一系列的不对称分裂和对称分裂以及多次细胞命运决定和细胞分化形成的,因而气孔发育的调控也成为近些年研究细胞分裂和分化的理想模型和热点。已知多肽和油菜素内酯作为信号物     

一种获得叶片表皮观察气孔的简易方法及其应用

为方便对植物气孔进行发育和生理学研究,我们报道了一种用普通塑料透明胶带粘贴植物叶片下表皮,再刮去叶肉细胞保留叶片表皮观察气孔的方法,此方法与撕取法、粘取法等方法相比具有操作简单、制片效率高、适用面广等特点。在大豆,小麦,玉米等农作物上应用效果很好,适宜对不同发育阶段和时期的气孔分布、气孔变化动态和形态学指标的研究。     

腐殖酸水溶肥料对水分胁迫下小麦光合特性及产量的影响

为了解腐殖酸水溶肥料对水分胁迫下小麦光合特性及产量的影响。以‘永良四号’为试验材料,采用盆栽方法研究了拔节期水分胁迫后,腐殖酸水溶肥料对小麦叶绿素含量、光合速率、气孔导度、蒸腾速率及产量的影响。结果表明,在不同水分胁迫下,腐殖酸水溶肥料均有效地改善了小麦光合特性,与对照相比,叶绿素含量增加5.62%~84.32%,光合速率增加0.87%~75.38%,气孔导度降低7.96%~53.25%,蒸腾速率降低15.96%~58.32%。水分胁迫后,净光合速率和叶绿素含量下降。但在水分胁迫时喷施腐殖酸水溶肥料,叶绿素含量和净光合速率增加,蒸腾速率减弱,因而水分利用效率提高。小麦增产4.48%~7.75%,增产效果显著,增产幅度为：正常供水>适度控水>中度水分胁迫。综合分析表明,腐殖酸水溶肥料能改善小麦光合特性,增加其产量。     

Evaluation of winter wheat cultivars for drought resistance

Summary Cultivars of winter wheat (Triticum aestivum L. em. Thell.), considered by wheat breeders to be drought sensitive or drought resistant, were grown under two irrigation regimes (daily or weekly waterings) to determine physiological responses to drought and to evaluate methods to use in screening for drought resistance. Leaf water potential, stomatal resistance, plant resistance to water flow, and soil water potential were measured for three weeks on vernalized plants in a growth chamber. When water was lacking, drought-sensitive plants had a lower leaf water potential than did drought-resistant plants. With both daily and weekly waterings, stomatal resistance was higher in drought-resistant plants than in drought-sensitive plants. Plant resistance to water flow, calculated as the difference between the soil water potential and leaf water potential divided by the amount of water used by the plant, was usually higher in drought-resistant plants than in the drought-sensitive plants. The results showed that, when screening for drought resistance, stomatal resistance was a better method to use than determinations of leaf water potential or plant resistance to water flow.Journal article 3578 of the Agricultural Experiment Station, Oklahoma State University. Work was partially supported by a Grant-in-Aid of Research from Sigma Xi, The Scientific Research Society of North America, to the senior author.     

氧肥后移对超高产小麦产量及生理特性的影响

在小麦超高产栽培条件下,研究了氮肥不同追施时期追施量对籽粒产量及植株生理特性的影响。结果表明,超高产小麦施氮量以２４０ｋｇ／ｈｍ＾２,基追比例５：５为宜,追氮量过少或过多均不利于进一步提高小麦产量。氮肥不同追施时期对小麦产量也有不同的影响,小花雌雄蕊分化期和药隔形成期追肥可明显改善植株后期光合性能,降低叶片气孔阻力,并使植株体内保持高水平的保护酶活性,降低后期细胞膜脂过氧化水平,延缓植株衰老,从而     

丛枝菌根真菌（AMF）在土壤修复中的生态应用

丛枝菌根真菌作为植物根系和土壤的联系纽带,能够直接影响包括植物的矿质营养、生长发育及抗逆性、抗病性等许多方面的生理机能,并通过对土壤结构及生物群落结构的影响间接地影响宿主植物的生长。本文就其在以上各方面的具体应用做一简述。另外,提出了利用分子生物学技术进行AMF分类学体系等方面进一步研究的观点。     

Phosphorus Fertilization and Fungal Inoculations Affected the Physiology,Phosphorus Uptake and Growth of Spring Wheat Under Rainfed Conditions on the Canadian Prairies

Some fungal species have been shown to improve plant growth under drought conditions and to increase plant phosphorus (P) uptake from the soil. How moisture limitation, P availability and fungal inoculation interact to affect plant physiology and growth is, however, poorly understood. Here, we studied the combined effects of fungal (arbuscular mycorrhizal fungi (AMF) or Penicillium spp.) inoculations and phosphorus (P) fertilization (0, 45 and 90 kg ha^?1) on the net rate of photosynthesis, water‐use efficiency, P uptake and growth of spring wheat (Triticum aestivum var. Superb) under field conditions at two locations (Castor and Vegreville) in Alberta, Canada. Both fungal inoculation and P application increased the rate of photosynthesis. Under the same P level, AMF inoculation had a greater positive effect on the rate of photosynthesis than Penicillium inoculation. The AMF inoculation increased the instantaneous water‐use efficiency (WUEi) of plants at Castor, but not at Vegreville. Leaf carbon isotope discrimination (CID, Δ¹³C) increased with the rate of P application but was not affected by fungal inoculations. Phosphorus concentrations of stem and seed increased with both fungal inoculation and P application irrespective of location, with AMF inoculation showing the largest effects. The interaction between P addition and fungal inoculation was significant for stem P concentration in Vegreville. Both fungal inoculation and P application increased the leaf area index (LAI), biomass production and grain yield at both locations. Under the same P level, AMF inoculation had a greater positive effect on LAI, biomass production and grain yields than Penicillium inoculation. Morphological characters such as spike length and kernels/spike were also improved by fungal inoculation and P application at both locations. We conclude that the studied sites were deficient in P availability, and both fungal inoculation and P application improved P uptake and crop productivity, while the effect of fungal inoculation on water‐use efficiency was site specific.     

烯效唑对小麦苗期生长的调控作用

试验结果表明，小麦播前种子处理（拌种，闷种或浸种），对小麦苗期生长的生物学效应，一是降低麦苗生长速度，控制苗高；二是促进麦苗分蘖，增加年前分蘖数，此外，还可提高叶片叶绿素含量及光合效率，降低地上部呼吸强度，增加干物质积累，提高麦苗素与抗寒性，收到增穗增产的效果。     

光照和水流阻力对小麦蒸腾波动的影响

生长在步入式植物生长箱中的小麦幼苗, 当光子流密度(PFD)下降时, 蒸腾速率发生了有规律的波动。 波动周期与下降幅度有关, 下降幅度越大, 周期越长。 在波动进行期间, 当再次降低PFD(100 μmol m-2s-1到30 μmol m-2s-1)后, 波动频率和振幅都有所降低。 通过外界压力使叶鞘部木质部变形, 以导致在变形区的水流阻力增     

缺磷对不同穗型小麦光合生理特性和产量的影响

采用石英砂培养的方法，研究了拔节期和挑旗期缺磷对大穗型小麦CA9325和多穗型小麦晋麦2号（JM2）生长后期旗叶的净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Cs）、细胞间隙CO2浓度（Ci）和气孔限制值（Ls）等光合生理性状，光合产物积累和产量构成的影响。结果表明：（1）缺磷降低两品种旗叶的净光合速率、蒸腾速率、气孔     

水分亏缺条件下冬小麦几个抗旱性状的应用价值

在盆栽水分亏缺条件下,以15个抗旱性不同的冬小麦品种(系)为材料,对其8个抗旱性状的应用价值进行了研究.结果表明,通过乳熟期旗叶气孔阻力和蒸腾速率、两种用水效率(分别用干重和粒重表示)对单株粒重进行选择,其效率比通过3个农艺性状(单株干重、株高、顶部3叶总面积)的要低得多,说明前者在抗旱育种中的应用价值不大.     

Role of Arbuscular Mycorrhiza in Alleviating Salinity Stress in Wheat (Triticum aestivum L.) Grown Under Ambient and Elevated CO2

Plant growth and development are influenced by future elevated atmospheric CO₂ concentration and increased salinity stress. AM (arbuscular mycorrhiza) symbiosis has been shown to improve plant growth and resistance to environmental stresses. The aim of this study was to investigate the potential role of AM fungus in alleviating salinity stress in wheat (Triticum aestivum L.) plants grown under ambient and elevated CO₂ concentrations. Wheat plants inoculated or not inoculated with AM fungus were grown in two glasshouses with different CO₂ concentrations (400 and 700 μmol l^?1) and salinity levels (0, 9.5 and 19.0 dS m^?1). Results showed that salinity stress decreased and elevated CO₂ increased AM colonization. AM inoculation increased plant dry weight under elevated CO₂ and salinity stress. Stomatal conductance, density, size and aperture of AM plants were greater than non‐AM plants. AM fungi enhanced NUE by altering plant C assimilation and N uptake. AM plants had higher soluble sugar concentration and [K⁺]: [Na⁺] ratio compared with non‐AM plants. It is concluded that AM symbiosis improves wheat plant growth at vegetative stages through increasing stomatal conductance, enhancing NUE, accumulating soluble sugar, and improving ion homeostasis in wheat plants grown at elevated CO₂ and salinity stress.