阔叶红松林3种阔叶树种柄叶性状变异与相关性

叶包括叶片和叶柄, 二者在结构和功能上密切相关, 探究叶片性状和叶柄性状变异及性状间相关关系的影响因素对了解植物叶水平上的生物量分配策略具有重要意义。该研究以阔叶红松(Pinus koraiensis)林内3种主要阔叶树种白桦(Betula platyphylla)、紫椴(Tilia amurensis)、五角枫(Acer pictum subsp. mono)为研究对象, 每个树种选取小树(胸径: 1-6 cm)、中等树(胸径: 15-20 cm)、大树(胸径: 35-45 cm)各10株样树; 另针对大树, 考虑取样冠层位置对其结果的影响。通过测定叶片面积、叶片干质量、叶柄长和叶柄干质量, 主要探讨树种、植株大小和冠层位置(大树)对叶片性状和叶柄性状变异及其性状间相关性的影响。结果显示: (1)树种和植株大小对4个性状均存在显著影响, 3个树种小树的叶柄长和叶柄干质量显著小于大树, 紫椴和五角枫小树的叶片干质量也显著小于大树, 而白桦和紫椴小树的叶片面积显著大于大树; 对于大树, 冠层位置对4个性状变异的影响因树种而异。(2)叶片性状和叶柄性状表现为显著的异速生长关系, 且3个树种的回归斜率为紫椴>白桦>五角枫; 在白桦不同植株大小间的回归斜率为小树>大树>中等树, 而紫椴和五角枫大树的回归斜率最大; 对于大树, 在不同冠层位置叶片性状和叶柄性状间的相关关系存在共同斜率。研究结果表明叶片性状和叶柄性状的变异及其相关关系受树种和植株大小的显著影响, 冠层位置对大树柄叶性状变异及相关关系的影响则相对较小。     

不同气候带间成熟林植物叶性状间异速生长关系随功能型的变异

为研究不同生物气候带内植物叶片大小与叶柄干重间的异速生长关系, 探讨不同植物功能型对叶内异速生长关系的效应, 在黑龙江呼中、吉林长白山、北京东灵山、浙江古田山、湖北神农架和四川都江堰6个地区, 选择典型地带性成熟林进行主要木本植物的叶片和叶柄性状的测定与统计分析。结果表明: 不同功能型和气候带植物叶片干重、面积、体积均与叶柄干重之间存在着显著的异速生长关系, 共同斜率分别为0.82、0.70和0.80, 均显著小于1.0。在相同叶柄干重下, 灌木较乔木支持更大的叶片体积, 但它们支持的叶片干重与叶片面积无显著差异; 常绿植物在给定叶柄干重下较落叶植物支持更高的叶片干重与体积, 但其支持的叶片面积小于落叶植物; 除神农架地区外, 在给定叶柄干重下, 亚热带的古田山、都江堰地区的植物较温带地区的植物支持更大的叶片干重、面积与体积, 而亚热带神农架地区的植物叶柄支持的叶片大小(面积、体积、干重)与温带地区相近。结果表明, 叶柄限制了叶片的不断增大(包括面积、体积和干重), 叶片和叶柄之间的异速生长关系受功能型、气候带及生境条件的影响。     

不同木本植物功能型当年生小枝功能性状差异

为探讨不同植物功能型之间小枝功能特征的差异,在重庆金佛山和缙云山分别采集20和26个木本植物,选择当年生的小枝测定其叶片和枝条性状。结果表明:1)叶片厚度表现为:落叶植物<常绿植物,乔木<灌木;单叶面积和叶片总面积表现为:落叶植物>常绿植物,乔木>灌木;不同植物功能型间小枝的叶片数量均无显著差异。2)落叶植物和乔木的小枝横截面积、小枝长度和小枝干重均显著高于常绿植物和灌木,不同植物功能型间小枝密度无显著差异。3)与常绿植物和灌木相比,落叶植物和乔木有较高的展叶效率(单位长度小枝支撑的叶片面积),小枝的出叶强度(单位长度小枝支撑的叶片数)无显著差异。4)在小枝水平上,常绿植物比落叶植物投入更多的生物量到叶片。     

我国温带山地森林48种常见树种叶片重量-出叶强度的关系

叶片是植物的主要光合器官, 其质量与数量的权衡关系体现植物对环境的适应策略。在全球气候变化的背景下, 研究叶片质量与数量关系有助于理解植物对环境变化的响应趋势。该研究应用标准化主轴回归方法, 探讨了我国温带山地森林中48个常见树种的单叶干重与出叶强度的权衡关系。结果表明, 所有物种以及落叶阔叶林、常绿和落叶阔叶树种、单叶以及亚冠层阔叶树种的单叶干重与出叶强度表现为异速生长关系; 针叶林、针阔混交林、常绿及落叶针叶树种、复叶以及冠层阔叶树种则表现为等速生长关系。研究结果表明, 叶大小和出叶强度并无恒定的权衡关系。     

豆科复叶和单叶树种的光合-水分关系分析北大核心CSCD

以豆科(Fabaceae)11个复叶树种和6个单叶树种为材料,测定他们的气孔导度、叶片水力导度、水势、相对含水量等指标,分析叶型对枝叶光合水分关系的影响。结果显示,复叶树种正午叶轴水势(-0.91MPa)与单叶树种正午枝条水势(-0.88MPa)间无显著差异,但正午枝条水势(-0.60MPa)显著高于单叶树种。复叶树种正午气孔导度降低的百分比(55.3%)显著高于单叶树种(34.1%)。叶片、叶轴和枝条正午水势两两之间均显著正相关,但与正午气孔导度之间均不存在相关性。本研究中,17个树种的正午叶片水力导度与气孔导度间显著正相关(r=0.79,P<0.001),但他们与气孔导度降低百分比间呈负相关(r=-0.81,P<0.001),说明叶片导水率对日间气孔导度的维持具有重要作用。研究结果表明单叶和复叶树种在光合水分关系上存在明显差异,说明他们对环境条件具有不同的适应策略。     

发育阶段和海拔对岷江源区陇蜀杜鹃小枝功能性状及生物量分配的影响

本研究分析了岷江源区卡卡山典型高山灌丛植物陇蜀杜鹃不同发育阶段(花芽期和开花期)及不同海拔(3600 m低海拔和3800 m高海拔)下功能小枝和叶片性状的差异,以及空间异质性对花芽期和开花期小枝功能性状相关性及其权衡作用的影响。结果表明: 低海拔同一生长期陇蜀杜鹃小枝长度显著大于高海拔,高海拔开花期小枝的花数量和花质量显著高于低海拔。同一海拔花芽期的小枝质量、叶片数量、总叶质量、总叶面积和总叶柄质量均显著大于开花期,单叶质量和单叶柄质量均显著小于开花期。与花芽期相比,开花期叶生物量占比减少了13%,而小枝质量占比显著增加。小枝的生物量权衡表明,花芽期性状倾向于小枝质量,开花期倾向于总叶质量;花芽期的叶偏好分配于单叶质量,低海拔和高海拔开花期叶片分别偏好分配到单叶柄质量和单叶质量。低海拔开花期小枝质量与总叶面积、总叶质量均为异速生长,单叶柄质量和单叶面积为异速生长。海拔和发育阶段共同影响了陇蜀杜鹃功能小枝和叶片的性状。     

豆科复叶和单叶树种的光合-水分关系分析

以豆科(Fabaceae) 11个复叶树种和6个单叶树种为材料,测定他们的气孔导度、叶片水力导度、水势、相对含水量等指标,分析叶型对枝叶光合水分关系的影响。结果显示,复叶树种正午叶轴水势(-0. 91 MPa)与单叶树种正午枝条水势(-0.88 MPa)间无显著差异,但正午枝条水势(-0.60 MPa)显著高于单叶树种。复叶树种正午气孔导度降低的百分比(55.3%)显著高于单叶树种(34.1%)。叶片、叶轴和枝条正午水势两两之间均显著正相关,但与正午气孔导度之间均不存在相关性。本研究中,17个树种的正午叶片水力导度与气孔导度间显著正相关(r=0.79,P 0.001),但他们与气孔导度降低百分比间呈负相关(r=-0.81,P 0. 001),说明叶片导水率对日间气孔导度的维持具有重要作用。研究结果表明单叶和复叶树种在光合水分关系上存在明显差异,说明他们对环境条件具有不同的适应策略。     

北京植物园不同功能型植物叶经济谱

通过对北京植物园不同功能型植物的叶片光合参数、叶绿素荧光参数、叶面积、叶干质量以及叶氮含量等性状参数进行测定,分析了不同功能型植物的叶经济谱.结果表明: 生活型中草本植物、生活史中一年生植物、光合型中C4植物靠近叶经济谱中快速投资-收益型物种的一端,而生活型中乔木和灌木、生活史中多年生植物、光合型中C3植物位于缓慢投资-收益型物种的一端,表明不同功能型植物通过叶片性状间的权衡采取不同的环境适应策略,验证了不同功能型植物叶经济谱的存在.不同功能型植物叶片性状具有明显差异,其中不同生活型间的叶片比叶面积(SLA)、叶氮含量(N_mass)、最大净光合速率(A_mass)、光合氮利用效率(PNUE)均表现出草本植物>藤本植物>灌木>乔木;不同生活史间一年生植物的SLA、N_mass、A_mass、PNUE均显著高于多年生植物;不同光合型间植物的A_mass、PNUE、PSⅡ实际光化学效率(Φ_PSⅡ)均表现出C4>C3.N_mass、A_mass、SLA两两之间呈显著正相关,而PSⅡ有效光化学量子产量(F_v′/F_m′)与SLA呈显著负相关;PNUE与SLA呈显著正相关.     

兰州北山半干旱区刺槐叶大小-数量权衡与坡向间的关系

权衡关系是生活史对策理论的基础,叶大小-数量的权衡关系对理解不同生境下植物生物量分配具有重要的意义。采用标准化主轴估计(standardized major axis estimation,SMA)方法,研究了西北半干旱区兰州市北山各坡向人工林刺槐叶数量和大小的生长关系。结果表明:随坡向由北坡向东坡、西坡和南坡转变,植物群落盖度、高度和土壤含水量逐渐减小,刺槐小枝单叶面积和单叶片干重逐渐减小,出叶强度逐渐增大;4个坡向刺槐小枝出叶强度与单叶面积、单叶片干重均呈显著的负相关关系(P0.05),并存在接近-1的共同斜率;随坡向由北坡向东坡、西坡和南坡转变,出叶强度与单叶面积、单叶片干重四组关系的回归方程截距均逐渐减小。刺槐叶大小-数量的权衡关系,反映了植物功能性状对异质生境的响应和适应,以及植物资源分配的权衡机制。     

兰州市典型绿化树种叶性状间的权衡关系

植物叶性状的权衡关系反映了植物对环境的高度适应性及其在复杂生境下的自我调控能力,了解半干旱区城市绿化树种叶性状间的权衡关系,比较不同生长型(针叶和阔叶)树种异速生长的差异有助于进一步认识植物的进化机制。以兰州市典型绿化树种(13种针叶树和47种阔叶树)为对象,测量部分叶性状,采用标准化主轴估计和系统独立比较分析的方法比较不同性状间的权衡关系。结果表明:不同生长型树种叶面积、叶体积与叶片干重之间均为等速生长关系,针叶和阔叶树种间并无显著差异;叶厚与叶面积间为"此消彼长"的权衡关系,但并不显著;阔叶叶长与叶宽间异速生长斜率为0.764。兰州市典型绿化树种叶性状间的权衡可能是长期适应黄土高原特殊生境的自适应过程,也说明部分性状间存在协变关系,阔叶绿化树种的权衡表明其符合"快速投资-收益"特征。     

The contrasting role of auxin in submergence-induced petiole elongation in two species from frequently flooded wetlands

The involvement of auxin in the submergence-induced petiole elongation has been investigated in Rumex palustris and Ranunculus sceleratus. Both wetland species are capable of enhanced petiole elongation upon submergence or treatment with exogenous ethylene (5μl l⁻¹). Treatment of intact Rumex palustris plants with 1-naphthalene acetic acid (NAA) at 10⁻⁴ M enhanced petiole elongation, while treatment with N -1-naphthylphthalamic acid (NPA) had no effect on petiole elongation. The elongation response after NAA or NPA treatment was comparable for plants in both submerged and drained conditions. Pre-ageing of detached petioles of Rumex palustris for 3 h in light or in dark conditions had no effect on the submergence-induced elongation. In comparison to intact plants, detached petioles of Rumex palustris , with or without lamina, did not show significant differences in responsiveness to IAA between drained or submerged conditions. This was in contrast to Ranunculus sceleratus where submergence caused a clear increase in responsiveness towards IAA. Removal of the lamina, the putative source of auxin, or treatment with NPA did not hinder the submergence-induced elongation of detached Rumex palustris petioles, but severely inhibited elongation of detached Ranunculus sceleratus petioles. This inhibition could be restored by application of NAA, suggesting the specific involvement of auxin in the submergence response of Ranunculus sceleratus. It is concluded that, in contrast to Ranunculus sceleratus , auxin is probably not involved in the submergence-induced petiole elongation of Rumex palustris.     

EFFECTS OF TWIG SIZE ON BIOMASS ALLOCATION WITHIN TWIGS AND ON LAMINA AREA SUPPORTING EFFICIENCY IN RHODODENDRON: AL. LOMETRIC SCALING ANALYSES

 当年生小枝是多年生植物体上最活跃的部分之一, 其生物量分配是植物生活史对策研究的一个重要内容。该文采用标准化主轴估计(Standardized major axis estimation, SMA)和系统独立比较分析(Phylogenetically independent contrast analysis, PIC)的方法, 研究了杜鹃花属(Rhododendron)植物一年生小枝的大小对小枝叶片、叶柄和茎的生物量分配的影响, 以及对叶面积支持效率(即单位质量小枝支持的叶面积)的影响。结果显示: 1)小枝大小对叶片生物量分配比率的影响不显著, SMA斜率为1.040 (95%的置信区间(CI)=0.998～1.085); 但是, 小枝越大, 叶柄生物量分配比例越高(SMA斜率为1.245, 显著大于1.0, 呈显著的异速生长关系)。2)小枝越小, 单叶面积越小(支持Corner法则), 单位质量小枝所支持的叶面积越大, 即具有较小枝条和较小叶片的物种可能具有较高的叶面积支持效率。这些结果有助于我们更好地理解亲缘关系十分接近的杜鹃花属植物, 在不同生境条件下叶片大小的差异, 以及为什么在胁迫生境条件下小叶物种更为常见。     

Do we Underestimate the Importance of Leaf Size in Plant Economics? Disproportional Scaling of Support Costs Within the Spectrum of Leaf Physiognomy

BACKGROUND: Broad scaling relationships between leaf size and function do not take into account that leaves of different size may contain different fractions of support in petiole and mid-rib. METHODS: The fractions of leaf biomass in petiole, mid-rib and lamina, and the differences in chemistry and structure among mid-ribs, petioles and laminas were investigated in 122 species of contrasting leaf size, life form and climatic distribution to determine the extent to which differences in support modify whole-lamina and whole-leaf structural and chemical characteristics, and the extent to which size-dependent support investments are affected by plant life form and site climate. KEY RESULTS: For the entire data set, leaf fresh mass varied over five orders of magnitude. The percentage of dry mass in mid-rib increased strongly with lamina size, reaching more than 40 % in the largest laminas. The whole-leaf percentage of mid-rib and petiole increased with leaf size, and the overall support investment was more than 60 % in the largest leaves. Fractional support investments were generally larger in herbaceous than in woody species and tended to be lower in Mediterranean than in cool temperate and tropical plants. Mid-ribs and petioles had lower N and C percentages, and lower dry to fresh mass ratio, but greater density (mass per unit volume) than laminas. N percentage of lamina without mid-rib was up to 40 % higher in the largest leaves than the total-lamina (lamina and mid-rib) N percentage, and up to 60 % higher than whole-leaf N percentage, while lamina density calculated without mid-rib was up to 80 % less than that with the mid-rib. For all leaf compartments, N percentage was negatively associated with density and dry to fresh mass ratio, while C percentage was positively linked to these characteristics, reflecting the overall inverse scaling between structural and physiological characteristics. However, the correlations between N and C percentages and structural characteristics differed among mid-ribs, petioles and laminas, implying that the mass-weighted average leaf N and C percentage, density, and dry to fresh mass ratio can have different functional values depending on the importance of within-leaf support investments. CONCLUSIONS: These data demonstrate that variation in leaf size is associated with major changes in within-leaf support investments and in large modifications in integrated leaf chemical and structural characteristics. These size-dependent alterations can importantly affect general leaf structure vs. function scaling relationships. These data further demonstrate important life-form effects on and climatic differentiation in foliage support costs.     

Failure of Ethylene to Change the Distribution of Indoleacetic Acid in the Petiole of Coleus blumei X frederici during Epinasty

The effect of ethylene on the distribution of applied indoleacetic acid in the petiole of Coleus blumei Benth. X C. frederici G. Taylor has been investigated during the development of epinastic curvature. Using intact plants, ¹⁴C-IAA was applied to the distal region of the leaf lamina and the accumulation of label in the abaxial and adaxial halves of 5 mm petiole sections was determined after 1.5, 3, and 6 hours. Over this period the label was transported out of the lamina into the petiole at a rate of at least 66 mm hr⁻¹. Of the total amount of label in the petiole sections, 24 to 30% was located in the adaxial half and this distribution was not altered significantly by exposing plants to an atmosphere containing 50 μl/l ethylene. Thus when epinastic curvature is induced by ethylene there is no associated increase in the IAA content of the expanding adaxial half. The role of endogenous IAA in petiole epinasty was studied by restricting its movement with DPX 1840 (3,3a-dihydro-2-[p-methoxyphenyl]-8H-pyrozolo{5,1-a}isoindol-8-one). The leaf petioles still showed an initial epinastic response to ethylene. It is concluded that ethylene-induced epinasty is not dependent upon either any change in the transport of IAA or its redistribution within the petiole.     

Construction of genetic linkage map of the medicinal and ornamental plant <Emphasis Type="Italic">Catharanthus roseus</Emphasis>

An integrated genetic linkage map of the medicinal and ornamental plant Catharanthus roseus, based on different types of molecular and morphological markers was constructed, using a F₂ population of 144 plants. The map defines 14 linkage groups (LGs) and consists of 131 marker loci, including 125 molecular DNA markers (76 RAPD, 3 RAPD combinations; 7 ISSR; 2 EST-SSR from Medicago truncatula and 37 other PCR based DNA markers), selected from a total of 472 primers or primer pairs, and six morphological markers (stem pigmentation, leaf lamina pigmentation and shape, leaf petiole and pod size, and petal colour). The total map length is 1131.9 cM (centiMorgans), giving an average map length and distance between two markers equal to 80.9 cM and 8.6 cM, respectively. The morphological markers/genes were found linked with nearest molecular or morphological markers at distances varying from 0.7 to 11.4 cM. Linkage was observed between the morphological markers concerned with lamina shape and petiole size of leaf on LG1 and leaf, stem and petiole pigmentation and pod size on LG8. This is the first genetic linkage map of C. roseus.     

Resistance of Pepper Lines to the Movement of Cucumber Mosaic Virus

The multiplication and the migration of cucumber mosaic virus (CMV) were studied in greenhouse conditions in one susceptible ‘Yolo wonder’ and two resistant ‘Milord’ and ‘Vania’ pepper varieties. DAS-ELISA tests have revealed that the virus is replicated in inoculated leaves of the resistant varieties as high as in the susceptible variety. In the susceptible variety ‘Yolo wonder’, CMV migrated from the leaf lamina to the petiole two days after inoculation and it became systemic three days later regardless the season. In ‘Milord’ the virus migrated from the leaf lamina to the petiole five days after inoculation and it became systemic during the winter 16 days after inoculation. Whereas plants of the same genotype were not infected systemically during the summer. In ‘Vania’, during the two seasons, CMV spread from the blade to the petiole five days after inoculation, but the virus was not detected beyond the inoculated leaf. These results show that ‘Milord’ and ‘Vania’ are resistant to CMV migration. Therefore, the resistance to CMV migration is affected by plant genotype and temperature. The study of effect of pepper plant phenology on infection has revealed that resistance to CMV migration is also affected by the development stage of the plants.     

The role of oxygen in submergence-induced petiole elongation in Rumex palustris: in situ measurements of oxygen in petioles of intact plants using micro-electrodes

In a study on the mechanism of stimulated petiole elongation in submerged plants, oxygen concentrations in petioles of the flood-tolerant plant Rumex palustris were measured with micro-electrodes. Short-term submergence lowered petiole partial oxygen pressure to c . 19 kPa whereas prolonged submergence under continuous illumination depressed oxygen levels to c . 8–12 kPa after 24 h. Oxygen levels in petioles depended on the presence of the lamina, even in submerged conditions, and on available light. In darkness, petiole oxygen levels in submerged plants dropped quickly to values as low as 0.5–4 kPa. It is hypothesized that prolonged submergence in the light is accompanied by a decrease in carbon dioxide in the petiole. Submergence-enhanced petiolar elongation rate was compared with emergent plants. Peak daily elongation rates occurred at the end of the dark period in emergent plants, but in the middle of the light period in submerged plants. We suggest that this shift in daily elongation pattern is induced by dependence of growth on photosynthetically derived oxygen in submerged plants. Implications of reduced oxygen for ethylene production are raised. Levels of 1- aminocyclopropane-1-carboxylic acid synthase and 1-aminocyclopropane-1-carboxylic acid oxidase and ethylene sensitivity are cited as potential factors in hypoxia-induced ethylene release.     

ORGANIZATION AND ONTOGENY OF THE VASCULAR SYSTEM IN THE PETIOLE OF EASTERN COTTONWOOD

The topologic arrangement of petiolar bundles varies within the length of the cottonwood petiole. Each petiolar bundle is formed by the subdivision and aggregation of acropetally differentiating subsidiary bundles in a predictable pattern. The subsidiary bundles provide vascular continuity between the stem and specific portions of the leaf lamina. Spot-labeling of individual veins with ¹⁴CO₂, freeze substitution, and microautoradiography were used to establish the relation between the secondary veins of the lamina and the vasculature of the petiole. Within the petiole vasculature each subsidiary bundle was continuous with a specific portion of the lamina and seemed to have a separate function. Subsidiary bundles continuous with the central leaf trace were closely related functionally to the tip region of the lamina, while the subsidiary bundles continuous with the lateral leaf traces were functionally related to the middle and basal portions of the lamina.     

The production of strawberry plants from callus cultures

Shoots were regenerated from callus of the commercially important strawberry varieties Bogota, Brighton, Cambridge Favourite, Hapil, Ostara, Rapella, Red Gauntlet and JILA33 which is a promising selection from a current breeding programme.The callus was initiated from explants of petiole or lamina of leaves of micropropagated shoots in vitro or of lamina or peduncle from greenhouse plants. There was more shoot regeneration with callus from lamina than from petiole although with the variety Hapil, regeneration occurred only with callus from peduncle.With seven of the varieties, shoot regeneration occurred on culture media with BAP and 2,4-D whilst with the remaining variety, Cambridge Favourite, it occurred only with medium which contained 1AA- alanine conjugate in place of 2,4-D.Regenerated shoots rooted readily and the plants produced are being studied for somaclonal variation.