中亚热带樟科3种植物幼苗叶结构型性状的种间差异及其相关性

为了揭示植物叶功能性状对全球气候变化的响应和适应规律,以樟科3种植物幼苗为研究对象,将其人工采集的种子经低温沙藏并于温室培育,然后将幼苗移栽到野外同质园中自然生长,研究中亚热带樟科植物刨花楠(Machilus pauhoi)、香樟(Cinnamomum camphora)和闽楠(Phoebe bournei)两年生幼苗生长季节9种叶结构型性状的种间差异及其相关性。结果显示,(1)在3种植物幼苗中,香樟叶面积、叶厚度、叶体积、叶氮磷比最大,叶氮浓度最高,叶组织密度最小;闽楠叶组织密度、叶干物质含量最大,叶磷浓度最高,叶面积、叶体积、比叶面积、叶氮磷比最小,叶氮浓度最低;刨花楠比叶面积最大,叶厚度、叶干物质含量最小,叶磷浓度最低;3种植物幼苗的叶厚度之间均无显著差异。(2)Pearson相关分析和线性回归分析结果表明,樟科3种植物幼苗的叶面积与叶体积间呈极显著正相关(P0.01)、与叶干物质含量间呈极显著负相关(P0.01)、与叶磷浓度间呈极显著负相关(P0.01)、与叶组织密度间呈显著负相关(P0.05)、与叶氮浓度间呈显著正相关(P0.05);叶厚度与比叶面积间呈显著负相关(P0.05)、与叶干物质含量间呈显著正相关(P0.05);叶体积与叶组织密度间呈极显著负相关(P0.01)、与叶氮浓度间呈极显著正相关(P0.01)、与叶磷浓度间呈显著负相关(P0.05);叶组织密度与叶磷浓度间呈显著正相关(P0.05);比叶面积与叶干物质含量间呈极显著负相关(P0.01)、与叶磷浓度间呈极显著负相关(P0.01);叶干物质含量与叶磷浓度间呈极显著正相关(P0.01)。这表明在同质园中生长的刨花楠、香樟和闽楠幼苗的9种叶结构型性状表现出一定的种间差异,不同物种同一叶结构型性状指标的大小顺序、种间差异及其显著性不同;3种植物幼苗不同叶结构型性状之间的相关性及其显著程度也不同。本研究结果为揭示樟科3种植物幼苗叶功能性状对全球气候变化的响应和适应规律提供了基础数据。     

壳斗科五树种幼苗叶片结构型性状及其相关关系

通过种子的人工采集、低温沙藏和温室培育后,将幼苗移栽到环境条件相同的同质园中自然生长,研究了中亚热带壳斗科丝栗栲(Castanopsis fargesii)、苦槠(C.sclerophylla)、锥栗(Castanea henryi)、板栗(C.mollissima)和麻栎(Quercus acutissima)2年生幼苗生长季节的叶面积、叶厚度、比叶面积、叶干物质含量、叶氮浓度、叶磷浓度和叶氮磷比7种结构型性状的差异及其相关关系。结果表明:(1)在5树种幼苗中,锥栗幼苗的叶面积和比叶面积最大、叶氮浓度最高,其叶干物质含量最低;丝栗栲幼苗的叶面积最小、叶氮浓度和叶磷浓度最低;苦槠幼苗的叶厚度和比叶面积最小,其叶干物质含量最高;板栗幼苗则是叶厚度最小;同时5树种幼苗叶片的氮磷比均无显著差异(P0.1)。(2)Pearson相关和线性回归分析表明,壳斗科5树种幼苗的叶面积与叶氮浓度极显著正相关(P0.01),并与比叶面积显著正相关(P0.05);叶厚度与比叶面积极显著负相关(P0.01),其与叶干物质含量显著正相关(P0.05);比叶面积与叶干物质含量极显著负相关(P0.01),并与叶氮浓度极显著正相关(P0.01),同时与叶磷浓度显著负相关(P0.05);叶氮浓度与叶干物质含量、叶磷浓度分别为显著负相关(P0.05)和显著正相关(P0.05)。该研究结果表明壳斗科5树种幼苗叶片的7种结构型性状表现出了一定的种间差异性,但同一结构型性状的大小顺序和种间差异的显著性不同;同时所有树种幼苗叶片各结构型性状间的相关性及其显著程度不同。     

阔叶红松林不同演替阶段灌木叶片碳氮磷化学计量特征及其影响因素

灌木是森林生态系统的重要组成部分, 对于演替进程中灌木叶片化学计量特征的研究, 有助于全面理解和预测森林演替过程。该研究以黑龙江凉水国家自然保护区内处于阔叶红松(Pinus koraiensis)林不同演替阶段中的白桦(Betula platyphylla)次生林、落叶阔叶混交林、针阔混交林、阔叶红松林的灌木为研究对象, 分析其叶片的碳(C)、氮(N)、磷(P)化学计量特征差异, 并利用层次分割方法检验其与土壤、物种多样性的关系。主要结果为: 1)随着演替的进行, 阔叶红松林的叶片N含量显著高于其他3种林型, P含量与白桦次生林无显著差异, 但显著高于其他两种林型; 2)土壤N、P含量与个体尺度上的叶片N含量均呈显著正相关关系, 土壤P含量与叶片P含量呈显著正相关关系; 3)群落尺度上, 物种多样性和土壤化学性质共解释叶片N含量变异的82%和叶片P含量变异的62%; 4)群落尺度上Shannon多样性指数与灌木叶片的N、P含量呈显著正相关关系, 与灌木叶片的C:N、C:P呈显著负相关关系。总之, 阔叶红松林4个演替阶段灌木均受到氮限制; 相较于土壤的化学性质, 物种多样性更好地解释了灌木化学计量的变异。     

高浓度臭氧对蒙古栎叶片酚类物质含量和总抗氧化能力的影响

采用开顶箱(OTC)法,研究了高浓度臭氧(80±8 nmol·mol^-1)熏蒸处理对蒙古栎叶片 中总酚、类黄酮、单宁及丙二醛(MDA)含量的影响,使用1,1-二苯基苦基苯肼(DPPH) 法测定了蒙古栎叶片的总抗氧化能力.结果表明:蒙古栎叶片中总酚、类黄酮、缩合单宁和MDA的含量都有所增加,其中总酚和缩合单宁含量分别增加了48.17%和26.77%,差异显著（P<0.05）;类黄酮和MDA含量分别增加了24.66%和5.26%,差异不显著(P＞0.05);蒙古栎叶片总抗氧化能力显著增强(P<0.05),且与叶片中总酚和缩合单宁含量呈显著的正相关关系.     

大兴安岭典型灌木叶片功能性状对环境因子的响应

以大兴安岭地区典型灌木为研究对象,测定兴安杜鹃(Rhododendron dauricum)、杜香(Ledum palustre)、越橘(Vaccinium vitis-idaea)和绣线菊(Spiraea salicifolia)4种灌木的叶厚度、叶组织密度、比叶面积、叶干物质含量、叶碳含量、叶氮含量、叶磷含量、叶碳氮比、叶氮磷比共9个叶片功能性状,探究不同灌木叶片功能性状特征及其与环境因子间的关系,揭示灌木的生态适应策略。结果表明：4种灌木的叶片功能性状差异均达显著水平(P<0.05);相对而言,杜香和越橘的叶厚度较大(分别为0.279、0.305 mm),比叶面积较小(220.95、211.90 cm²·g^-1),叶干物质含量较高(0.463、0.384 g·g^-1),说明它们对资源的利用率高,对环境的适应能力强;而兴安杜鹃和绣线菊主要通过减小叶片厚度、增大比叶面积来维持叶片合成有机物质的能力;4种灌木的比叶面积均与叶厚度、叶组织密度呈显著负相关;兴安杜鹃、杜香、绣线菊的比叶面积还与叶干物质含量呈显著负相关;...     

文冠果新梢发育过程酚类物质及相关酶活性变化特性

以文冠果新梢为试验材料,通过分析文冠果新梢生长发育过程中的茎尖、茎段、叶片的多酚、类黄酮、单宁及相关酶(苯丙氨酸解氨酶、多酚氧化酶)活性,研究了文冠果新梢枝条发育过程中不同部位酚类物质的积累规律及相关酶活性的变化规律。结果显示:(1)文冠果新梢生长期内(4~9月)随着季节的变化,多酚、类黄酮、单宁等酚类物质含量总体上呈现上升趋势,新梢同一时期不同部位的多酚、类黄酮、单宁等酚类物质含量的分布情况相似,皆为:叶茎尖茎段。(2)文冠果不同发育时期的茎叶苯丙氨酸解氨酶活性大小为:新梢幼嫩茎段及相应叶片半木质化茎段及相应叶片木质化茎段及相应叶片;新梢叶片的多酚氧化酶活性显著高于茎段,茎尖的最低;文冠果叶片有着极强的抗氧化能力,对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除率最高可达98.13%。(3)在4月29日前后,文冠果新梢各部位多酚、类黄酮和单宁含量上升趋势有显著差异,各部位苯丙氨酸解氨酶活性最低,而多酚氧化酶活性最高,木质化程度不同的茎段DPPH·清除率均降至最低,表明4月29日是文冠果新梢生长期的一个重要过渡生长阶段。(4)文冠果的新梢多酚、类黄酮、单宁之间呈极显著正相关关系;多酚、类黄酮、单宁与DPPH·清除率存在极显著正相关关系,与多酚氧化酶活性呈显著正相关关系,与苯丙氨酸解氨酶活性之间相关性不显著。研究表明,酚类物质含量是影响文冠果无性繁殖的主要因素,酚类物质含量越低,文冠果的扦插、嫁接、组培的成活率越高;新梢多酚、类黄酮、单宁等酚类物质含量在生长初期最低,后随着新梢的生长呈现显著上升趋势;文冠果无性繁殖最好在新梢生长初期进行,最佳时间为4~5月中旬。     

杉木人工林下原生与引入树种叶性状变异特征

叶性状在表征植物资源利用和生存策略方面具有重要作用。构建异龄复层林是改造人工纯林的有效措施,探究引入与原生树种叶性状变异有利于林下伴生树种的筛选。研究了引入乔灌木树种(如闽楠、蚊母树等13个树种)与原生乔灌木树种(苦槠、红紫珠等6个树种)的叶片形态、光合色素、碳氮磷生态化学计量和非结构性碳水化合物特征。结果表明:(1)总体上引入与原生乔木和灌木树种的叶形态性状差异较小,原生乔木的叶长和比叶面积显著小于引入树种与原生灌木。引入与原生树种间光合色素具有显著差异,引入乔木叶绿素含量显著高于原生乔木,不同功能群植物的比叶面积.叶绿素关系格局存在策略位移现象。引入树种叶碳含量显著大于原生树种,叶氮和叶磷含量显著大于原生乔木;引入树种和原生灌木的碳、氮、磷养分含量的变异系数较大;引入与原生树种叶碳氮磷生态化学计量没有一致变化规律。引入灌木叶可溶性糖含量、原生灌木淀粉含量均显著高于乔木树种,灌木的非结构性碳水化合物总量也显著高于乔木。(2)引入与原生树种叶性状呈显著协同变化趋势。所有叶性状中,比叶面积、叶绿素含量、叶氮含量、叶磷含量在乔木和灌木中均呈极显著正相关关系。主成分分析显示,引入乔木和灌木树种的叶性状接近,引入树种与原生灌木之间叶性状差异相对较小,但与原生乔木间的叶性状差异较大。总体上引入树种的叶性状与原生树种具有趋同适应特征,但不同生活型植物叶性状在林下弱光环境中仍产生一定分异,引入灌木可能比引入乔木更适应杉木林下生境。     

贡嘎山常绿落叶阔叶混交林主要树种叶功能性状

以贡嘎山常绿落叶阔叶混交林5种主要树种为研究对象,分析其叶片比叶面积(SLA)、叶干重(LDW)、碳(C)、氮(N)、磷(P)含量、同位素丰度(δ13C、δ15N)等叶属性特征,阐明常绿落叶阔叶混交林主要物种叶片性状的差异以及各种性状之间的相关关系,揭示主要树种叶片的水分和养分利用效率之间的关系以及这种关系对该群落中主要树种共存的影响机制。结果表明:贡嘎山常绿落叶阔叶混交林常绿树种与落叶树种比叶面积存在显著差异,叶片C含量与N、P含量呈显著负相关,N含量和P含量呈显著正相关;SLA与N含量、N∶P呈显著正相关关系,与δ13C、C含量、C∶N呈显著负相关关系,而与P相关性不显著;叶片δ13C与C∶N相关性不显著;SLA较高的叶片具有较高的叶片N含量,较低的叶C含量、氮素利用效率(NUE)和水分利用效率(WUE);叶片的WUE和NUE之间不存在权衡关系,未采用水氮耦合的权衡机制以适应潮湿多雨的环境;孑遗植物康定木兰(Indigofera souliei)和连香树(Cercidiphyllum japonicum)均采用异于非孑遗物种的养分利用策略,形成生态位的分化而共存于群落。     

胡杨异形叶结构型性状及其与胸径关系

对胡杨5种类型植株的叶片厚度、叶面积、比叶面积、叶片干重和干物质含量等5个结构型性状指标进行分析,研究叶片的结构型性状与胸径之间及各个结构型性状彼此间相互关系。结果表明:叶面积、叶厚度和叶干重与胸径呈极显著正相关(P0.01),叶片干物质含量与胸径间呈显著正相关(P0.05),比叶面积与胸径之间呈极显著负相关(P0.01),说明随着植株生长发育的进行,叶片的面积、厚度、干重和干物质含量均逐渐增加,而比叶面积逐渐减小。各性状指标间相关性表现为叶面积、叶厚度、叶干物质和叶片干物质含量任意2个指标之间均呈显著或极显著正相关;而比叶面积与这4个指标间均呈显著或极显著负相关。     

不同种源刨花楠林下幼苗叶功能性状与地理环境的关系

研究9个种源地天然刨花楠林下幼苗主要叶功能性状差异及其与地理环境的关系,分析刨花楠林下幼苗对地理环境变化的响应与适应机制.结果表明: 不同种源间刨花楠林下幼苗主要叶功能性状种内变异系数较大(8.8%～28.2%),其中种源间比叶面积、叶相对含水率、叶组织密度和叶厚差异显著,表明刨花楠林下幼苗具有较强的叶片形态可塑性.叶组织密度与叶干物质含量、叶相对含水率均呈显著正相关,与比叶面积、叶厚则呈显著负相关;比叶面积与叶干物质含量、叶面积均呈显著负相关,反映刨花楠林下幼苗可通过叶片性状组合的调整和平衡以响应地理环境变化.影响刨花楠林下幼苗叶功能性状可塑性的主要环境因子为经度、纬度、>10 ℃年积温和年均温.叶厚随着经度的增加而降低,叶干物质含量和叶相对含水率则随着经度的增加而增加;叶组织密度与经度和年均温呈显著正相关,且经度对其影响大于年均温;叶面积与>10 ℃年积温和经度呈显著正相关,且前者对其影响大于后者.     

Adaxial–abaxial polarity: The developmental basis of leaf shape diversity

Leaves of flowering plants are diverse in shape. Part of this morphological diversity can be attributed to differences in spatiotemporal regulation of polarity in the upper (adaxial) and lower (abaxial) sides of developing leaves. In a leaf primordium, antagonistic interactions between polarity determinants specify the adaxial and abaxial domains in a mutually exclusive manner. The patterning of those domains is critical for leaf morphogenesis. In this review, we first summarize the gene networks regulating adaxial–abaxial polarity in conventional bifacial leaves and then discuss how patterning is modified in different leaf type categories. genesis 52:1–18, 2014. © 2013 The Authors. Genesis Published byWiley Periodicals, Inc.     

Determinants of some leaf characteristics of Australian mangroves

Leaf characteristics reflecting the size, lifespan (longevity), moisture content (degree of succulence) and complexity of structure of 20 mangrove species were studied over several years at 13 locations along the tropical and subtropical Australian coast. These characteristics were found to fall generally within the ranges of those for woody species from other ecosystems. With the exception of one species, it was found that leaf longevity was related inversely to leaf moisture content, increasing from nearly 6 months in more succulent species to over 2 years in less succulent species. This suggested that more succulent leaves are less complex in their structure because they have less well‐developed ability to compartmentalize salt. There was a tendency also for leaf longevity to increase in species with larger leaves. These findings were consistent with the general view for land plants that leaf longevity is greater in species that have developed tolerance to environmental stress, salt particularly in the case of mangroves. Leaf tissue in such species is more robust or complex and requires greater metabolic resources in its construction; the plant is then advantaged by retaining the tissue for longer periods. Classification of the species considered here, based on their leaf longevity, moisture content and complexity, identified phylogenetically related species groupings that reflected these leaf longevity effects.     

Evolution of leaf developmental mechanisms

Leaves are determinate organs produced by the shoot apical meristem. Land plants demonstrate a large range of variation in leaf form. Here we discuss evolution of leaf form in the context of our current understanding of leaf development, as this has emerged from molecular genetic studies in model organisms. We also discuss specific examples where parallel studies of development in different species have helped understanding how diversification of leaf form may occur in nature.     

Relationships between sclerophylly,leaf biomechanical properties and leaf anatomy in some Australian heath and forest species

ABSTRACT

A previous study of 19 south-east Australian heath and forest species with a range of leaf textures showed that they varied considerably in leaf biomechanical properties. By using an index of sclerophylly derived from botanists' rankings (botanists' sclerophylly index, BSI) we determined that leaves considered by botanists to be sclerophyllous generally had both high strength and work to fracture (particularly in punching and tearing tests), both at the level of leaf and per unit leaf thickness. In the current study we have shown that leaves from the same species also varied considerably in leaf specific mass (46–251 g m^-2), neutral detergent fibre concentration (20–59% on a dry weight basis) and in leaf anatomy. Multiple regression indicated a very strong correlation between BSI and the first two components of a principal components analysis (PCA) of leaf anatomy (R ² = 0.91). In addition, there was strong correlation between the first component of a PCA of the mechanical properties (correlated with BSI) and the two axes derived from anatomical characteristics (R ² = 0.66). The anatomical properties contributing most to the significant component axes were thickness of palisade mesophyll and upper cuticle (axis 1) and percentage fibre (neutral detergent fibre) and lower epidermis thickness (axis 2). However, whether these relationships are causal, or reflect correlations with characteristics not measured in this study, such as vascularization and sclerification, is not clear. At a finer scale, however, there is evidence that there are various ways to be sclerophyllous, both in terms of anatomical and mechanical properties. This is illustrated by comparison of two of the sclerophyllous species, Eucalyptus baxteri and Banksia marginata.     

Diurnal cycles of leaf extension in unsalinized and salinized Beta vulgaris

Abstract. Continuous high resolution measurement of sugar beet leaf extension over 5 d in growth chambers showed average leaf extension rates (LER) in darkness to be from three to six times those in light for plants growing in non-salinized media. The changes in LER in light-dark transitions occurred within seconds, a response which was more rapid than stomatal opening or closing. When the growth medium was salinized to 100 mol m⁻³ NaCl, LER's were reduced by about 50% in darkness and 90% in light, markedly increasing the ratio of dark to light LER.
A 2-d episode of root-zone salinity imposed midway through a 5-d period of measurement decreased LER and produced higher leaf temperatures. LER and diurnal leaf temperature patterns reverted to their pre-salinized levels when root-zone salinity was removed. Thus, the effects of short episodes of high sodium chloride in the growth medium appear to be reversible, suggesting a water stress mechanism of growth reduction rather than toxicity effects of salt.     

叶脉结构与功能及其对叶片经济谱的影响

叶脉由贯穿于叶肉内部的维管组织及其外围机械组织构成, 多样化的脉序及网络结构使叶脉系统发生变异和功能分化。该文综述了叶脉系统结构与功能的最新研究进展。通过聚焦叶脉分级系统的结构与功能及其在叶片经济谱(LES)中的重要性, 解释叶脉性状与其它叶片功能性状之间的关系及机制。不同等级叶脉在机械支撑与水分运输方面存在功能分化, 其中1-3级粗脉在维持叶片形状和叶表面积以及物理支撑方面发挥重要作用, 有利于维持叶片最大受光面积; 4级及以上细脉具有水分调节功能, 它们与气孔相互协调, 影响叶片水分运输、蒸腾散热和光合作用速率。叶片生长过程与叶脉发育的动态变化模式决定叶脉密度, 并影响叶脉密度与叶片大小之间的关系: 叶面积与粗脉密度呈显著负相关, 与粗脉直径呈显著正相关, 而与细脉密度无关。与叶脉性状相关的叶片经济谱框架模型预测, 叶脉密度较高的叶片寿命短、比叶重较小, 叶片最大碳同化速率、代谢速率以及资源获取策略潜力较高。     

Leaf traits indicate survival strategies among 42 dominant plant species in a dry, sandy habitat, China

The objective of this paper was to assess the congruency of leaf traits and soil characteristics and to analyze the survival strategies of different plant functional types in response to drought and nutrient-poor environ-ments in the southeastern Ke'erqin Sandy Lands in China. Six leaf traits-leaf thickness (TH), density (DN), specific leaf area (SLA), leaf dry weight to fresh weight ratio (DW/ FW), leaf N concentration (Nmass), and N resorption efficiency (NREmass)-of 42 plant species were investi-gated at four sites. The correlations between leaf traits and soil characteristics-organic C (OC), total N (TN), total P (TP), and soil moisture (SM)-were examined. We found that the six leaf traits across all the 42 species showed large variations and that DW/FW was negatively correlated with OC, TN, TP, and SM (P<0.05), while other leaf traits showed no significant correlations with soil characteristics. To find the dissimilarity to accommodate environment, a hierarchical agglomerative clustering analysis was made of all the species. All the species clustered into three groups except the Scutellaria baicalensis. Species of group Ⅲ might be most tolerant of an arid environment, and species of group Ⅱ might avoid nutrient stress in the nutrient-poor environment, while group Ⅰ was somewhat intermediate. Therefore, species from the different groups may be selected for use in vegetation restoration of different sites based on soil moisture and nutrient conditions.