排序方式： 共有39条查询结果，搜索用时 15 毫秒
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通过测定具有代表性的四种室内环境条件下银心吊兰的固碳释氧量、释水量的变化,研究了银心吊兰叶片生长与环境条件相互作用,结果表明:在南向阳光充足的窗边,银心吊兰的固碳释氧量和释水量最大,但叶片生长较慢;光强稍弱的东向窗边,叶片生长较快,但固碳释氧量和释水量低于南向窗边;阴暗的条件下叶片的生长受到抑制,改善环境能力严重降低。 相似文献
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两种野生岩生植物的抗旱适应性研究 总被引：13，自引：1，他引：13
采用盆栽试验研究干旱胁迫下两种野生岩生植物金发草[Pogonatherumpanideum(Lam.)Hack]、丛毛羊胡子草(ErioophorumcomosumNees)的抗旱形态、生理表现。结果表明随着干旱胁迫程度加强,两种野生岩生植物的叶片相对电导率增大;胁迫初期可溶性蛋白含量小幅度增加,随后呈缓慢下降;金发草丙二醛(MDA)含量呈上升趋势,羊胡子草则先降后升;金发草可溶性糖含量先升后降,羊胡子草则一直呈现缓慢上升趋势;游离脯氨酸(Pro)含量均呈先升后降趋势。综合各项指标,丛毛羊胡子草抗旱性强于金发草。 相似文献
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Litter- and ecosystem-driven decomposition under elevated CO2 and enhanced N deposition in a Sphagnum peatland 总被引：1，自引：0，他引：1
Andy Siegenthaler Alexandre Buttler Luca Bragazza Edwin van der Heijden Jean-Michel Gobat 《Soil biology & biochemistry》2010,42(6):968-977
Peatlands represent massive global C pools and sinks. Carbon accumulation depends on the ratio between net primary production and decomposition, both of which can change under projected increases of atmospheric CO2 and N deposition. The decomposition of litter is influenced by 1) the quality of the litter, and 2) the microenvironmental conditions in which the litter decomposes. This study aims at experimentally testing the effects of these two drivers in the context of global change. We studied the in situ litter decomposition from three common peatland species (Eriophorum vaginatum, Polytrichum strictum and Sphagnum fallax) collected after one year of litter production under pre-treatment conditions (elevated CO2: 560 ppm or enhanced N: 3 g m−2 y−1 NH4NO3) and decomposed the following year under treatment conditions (same as pre-treatment). By considering the cross-effects between pre-treatments and treatments, we distinguished between the effects on mass loss of 1) the pre-treatment-induced litter quality and 2) the treatment conditions under which the litters were decomposing. The combination between CO2 pre-treatment and CO2 treatment reduced Polytrichum decomposition by −24% and this can be explained by litter quality-driven decomposition changes brought by the pre-treatment. CO2 pre-treatment reduced Eriophorum litter quality, although this was not sufficient to predict decomposition. The N addition pre-treatment reduced the decomposition of Eriophorum, due to enhanced lignin and soluble phenols concentrations in the initial litter, and reduced litter-driven losses of starch and enhanced litter-driven losses of soluble phenols. While decomposition indices based on initial litter quality provide a broad explanation of quantitative and qualitative decomposition, they can only be taken as first approximations. Indeed, the microbial ATP activity, the litter N loss and resulting litter quality, were strongly altered irrespective of the compounds' initial concentration and by means of processes that occurred independently of the initial litter-qualitative changes. The experimental design was valuable to assess litter- and ecosystem-driven decomposition pathways simultaneously or independently. The ability to separate these two drivers makes it possible to attest the presence of litter-qualitative changes even without any litter biochemical determinations, and shows the screening potential of this approach for future experiments dealing with multiple plant species. 相似文献
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强光胁迫常常导致植物的叶绿素含量下降,但是叶绿素合成受阻的突变体在光胁迫下会发生怎样的生理生化变化目前未见报道。本研究以金心吊兰为材料,研究了同一叶片的不同区带对短时强光胁迫的生理响应。结果表明,1)在正常的光照下,金心部分PSⅡ的活性显著低于其他部分,但活性氧含量却维持在较高的水平;2)在强光胁迫的6 h内,金心部分的活性氧波动不大,抗氧化酶活性变化也较小,均低于其他部分;3)短时强光胁迫导致吊兰叶片的非光化学淬灭上升,而金心部分上升幅度较少,说明吸收的过多光能在金心部分不是以热耗散的形式消耗,并且金心部分能在较短的时间内恢复到胁迫前的非光化学淬灭水平。 相似文献
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把吊兰放在不同营养液和不同营养液浓度下培养,结果表明:园试标准配方、山崎配方、斯泰纳配方三种配方中,山崎配方标准浓度营养液是最适合水培吊兰生长的营养液。随着山崎配方营养液浓度的降低,水培吊兰的新生叶数和新生根数呈逐渐降低的趋势。 相似文献
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通过对营养液水培、陶粒浇灌营养液、珍珠岩浇灌营养液、蛭石浇灌营养液、土培5种栽培条件处理下吊兰气孔参数的研究,结果表明,试验中所观察的吊兰叶片气孔呈圆型或椭圆型,保卫细胞半月形。靠近叶尖和叶中部位的气孔分布较叶缘和叶基的多,叶基部位气孔分布相对较少,从叶基到叶尖气孔密度逐渐增大,表现为：叶尖〉叶中〉叶基。不同栽培基质中吊兰叶片中段下表皮气孔参数相比较：土培处理的叶片中段气孔指数最大为41．63％,极显著地高于蛭石浇灌营养液、营养液水培、陶粒浇灌营养液处理;土培单个气孔面积最小,为896．98μm^2,极显著地低于蛭石浇灌营养液、营养液水培、陶粒浇灌营养液处理。 相似文献
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3种岩石边坡护坡植物叶片质膜透性和可溶性糖含量对低温胁迫的响应 总被引：1，自引：0，他引：1
以野生岩生植物金发草(Pogonatherum paniceum)和丛毛羊胡子草(Eriophorum comosum)为研究材料,以目前最常用的护坡植物之一狗牙根(Cynodon dactlylon)作为对照,研究低温胁迫下两种野生岩生植物叶片质膜透性和可溶性糖含量的变化情况。结果表明:在低温(0,-5,-10,-15,-20℃)胁迫下,随着温度的降低,丛毛羊胡子草、金发草和狗牙根等3种植物的电解质渗出率均增大,可溶性糖含量均增加;在5种处理温度下,丛毛羊胡子草电解质渗出率均低于金发草和狗牙根,而可溶性糖含量均高于金发草和狗牙根;半致死温度均低于金发草和狗牙根;3种植物的电解质渗出率在12月低于8月,而可溶性糖含量则相反,即12月高于8月。这一结果说明3种植物中丛毛羊胡子草的抗寒性最强,且自然温度缓慢降低有利于3种植物抗寒能力的诱导和提高。 相似文献
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The clear dependence of N2O production through denitrification on available nitrate in soil has been shown in many studies. Since N availability similarly limits the growth of plants, the resource competition with vegetation limits the activity of denitrifying microbes and may consequently moderate the N2O emissions from peatlands. We used uptake by Eriophorum vaginatum L. as a vegetation competition factor for microbes. The species was selected for the experiment because it has high nutrient use efficiency in low-nutrient conditions and high nutrient uptake efficiency in luxuriant nutrient conditions. We measured gaseous N flux as N2O (end product of denitrifier activity) in a restored peatland in central Finland with acetylene inhibition technique over a growing season from sample plots with varying addition levels and E. vaginatum cover. The resource competition effects were analysed with a model that used exponential decay dependence of N2O flux on the leaf area of E. vaginatum, and saturating response of N2O flux to addition level. The model explained the variation in N2O fluxes well (R2=0.86). The model simulation showed that the increasing nutrient uptake of E. vaginatum decreased the N2O fluxes exponentially. Simultaneously, denitrification appeared to saturate even in conditions with high availability of and low level of competition by vegetation. Thus, E. vaginatum is an effective competitor for in sedge-dominated peatlands that controls the availability of for denitrification, and consequently moderates the N2O emissions from peatlands. 相似文献