洛阳地区7个萌发较晚的紫斑牡丹生长节律研究分析

总结引种洛阳后萌发较晚的紫斑牡丹茎叶生长规律情况,结果表明,萌发期为3月上旬;7个品种紫斑牡丹的茎高、叶长和叶宽年平均生长量存在差异,表现出植株高矮和叶片大小的不同,但各指标的变化趋势基本一致。物候期比原产地提前30天。茎高生长起始时间早,速生期短,生长集中;叶生长的持续时间相对要长;叶宽生长的结束期更迟于叶长。3月12日-4月16日为这些紫斑牡丹茎生长高峰期,平均茎高生长量达23.56 cm;4月24日已完成茎高全年生长量,年平均生长量为23.99 cm。从3月下旬至4月中旬是叶片的迅速生长期,4月16日叶片大小定形,平均叶长、叶宽分别达到28.16 cm和23.80 cm。花期集中在4月16-26日,培育晚开新品种有重要意义。     

Structural variation in current-year shoots of broad-leaved evergreen tree saplings under forest canopies in warm temperate Japan

Stem length and leaf area of current-year shoots were measured in saplings of eight broad-leaved evergreen tree species growing under a forest canopy. Stem length varied over a range of one to two orders of magnitude within each species. In all species, both the number of leaves and the mean stem length between successive leaves were greater in longer shoots. Mean leaf size and stem length were not correlated in six of eight species, and only weakly positively correlated in the other two species. Thus, total leaf area per stem increased with stem length, but not in direct proportion: leaf area per stem length was smaller in shoots with long stems and larger in shoots with short stems. I conclude that the within-species variation in the leaf-stem balance of current-year shoots is related to variation in shoot functional roles, as has been observed for long and short shoots in many deciduous tree species: shoots with long stems are extension oriented and contribute to the framework of the crown, whereas shoots with short stems serve mainly for leaf display. Among species, large differences were found in the leaf area per stem length ratio. In the species with larger leaf area per stem length ratios, leaves had narrower blades or longer petioles, or both, resulting in a reduction of mutual shading among the leaves on the shoot.     

麻竹开花前后主要营养元素变化研究

研究了麻竹开花过程中植株不同部位N、P、K、Ca、Mg等营养元素含量及其变化。结果表明:在麻竹开花过程中,各种营养元素在植株不同部位的含量分别表现为:N,枝 > 秆 > 叶;P,叶 > 枝 ≥ 秆;K,未开花及开花前期为叶 > 枝 > 秆,开花盛期为枝 > 叶 > 秆;Ca,未开花及开花盛期为叶 > 秆 > 枝,开花前期为叶 > 枝 > 秆;Mg,叶 > 枝 > 秆。营养元素在植株同一部位的变化规律表现为:N在枝、秆、叶中的含量均为先降低再升高;P在枝、秆中含量逐渐升高、在叶中含量逐渐减少;K在枝、秆中含量先降低后升高、在叶中含量逐渐减少;Ca在枝中含量先升高再降低、在秆中含量逐渐减少、在叶中含量逐渐升高;Mg在枝和秆中含量先升高再降低、在叶中含量逐渐降低。研究结果可为竹子开花机理研究提供参考。     

Recovery of diurnal depression of leaf hydraulic conductance in a subtropical woody bamboo species: embolism refilling by nocturnal root pressure

Despite considerable investigations of diurnal water use characteristics in different plant functional groups, the research on daily water use strategies of woody bamboo grasses remains lacking. We studied the daily water use and gas exchange of Sinarundinaria nitida (Mitford) Nakai, an abundant subtropical bamboo species in Southwest China. We found that the stem relative water content (RWC) and stem hydraulic conductivity (K(s)) of this bamboo species did not decrease significantly during the day, whereas the leaf RWC and leaf hydraulic conductance (K(leaf)) showed a distinct decrease at midday, compared with the predawn values. Diurnal loss of K(leaf) was coupled with a midday decline in stomatal conductance (g(s)) and CO(2) assimilation. The positive root pressures in the different habitats were of sufficient magnitude to refill the embolisms in leaves. We concluded that (i) the studied bamboo species does not use stem water storage for daily transpiration; (ii) diurnal down-regulation in K(leaf) and gs has the function to slow down potential water loss in stems and protect the stem hydraulic pathway from cavitation; (iii) since K(leaf) did not recover during late afternoon, refilling of embolism in bamboo leaves probably fully depends on nocturnal root pressure. The embolism refilling mechanism by root pressure could be helpful for the growth and persistence of this woody monocot species.     

药用蕨皱边石杉的形态解剖学研究

对药用蕨皱边石杉茎、叶进行了外部形态、内部结构的解剖学研究，对孢子囊及孢子进行了扫描电镜观察。维管柱逐渐发展成为介于星状中柱和编织中柱之间的一种过渡类型中柱，木质部为外始式；叶为等面叶，外韧维管束。同时对石杉不同组织器官的组培繁殖存在的问题进行了分析和探讨。     

彩叶草的品种分类与园林应用

彩叶草品种繁多，是重要的彩叶植物。文章介绍了彩叶草的品种分类方法，依据茎的习性、叶的形态和叶色、色彩样式等主要特征，将彩叶草分为蔓生组、奇叶组、典型组、种子繁殖组和其他组。同时探讨了彩叶草在园林植物造景、观赏中的应用。     

紫叶桃（Prunus persica f．atropurpurea）的愈伤组织诱导和培养

紫叶桃是重要的园林彩叶树种,叶色美丽,观赏期长,具有很高的园林应用价值。以紫叶桃的叶片和嫩茎段为外植体,用不同浓度生长调节物质进行愈伤组织诱导试验,建立紫叶桃的再生体系。结果表明,诱导愈伤组织时,MS＋2mg／LBA＋1mg／L2,4-D对叶片诱导效果最佳,其诱导率达80％;MS＋1mg／LBA＋1mg／L2,4-D对茎段诱导效果最佳,其诱导率达100％。在MS＋1mg／LBA＋1mg／L NAA培养基上愈伤组织能直接分化出不定芽。     

假槟榔茎干分枝的形态发生

描述分枝假槟榔的形态特征,并对其成因进行分析。认为假槟榔这个侧枝是直接从主干叶腋中由茎花芽逆转后萌发生成,为偶发分枝,其生长方式与花苞类似,但这个叶鞘包被的是叶芽而不是花芽,由于营养生长相对于主干较弱,侧枝比主干略小,侧枝的环痕间距也比主干窄。     

Effectiveness of a detached‐leaf assay as a proxy for stem inoculations in backcrossed chestnut (Castanea) blight resistance breeding populations

A recently developed detached‐leaf blight resistance assay has generated interest because it could reduce the amount of time needed to evaluate backcrossed hybrid trees in the American chestnut blight resistance breeding programme. We evaluated the leaf inoculation technique on a sample of advanced progeny from the Indiana state chapter American Chestnut Foundation breeding programme, along with susceptible American chestnut (Castanea dentata), the recurrent parent, and resistant Chinese chestnut (Castanea mollissima), the donor parent for blight resistance. In experiments over 2 years using two pathogen isolates, we found no biologically meaningful relationship between leaf lesion size and the size (length and width) or severity (1–5 canker severity rating) of stem cankers on 5‐year‐old trees. Chinese chestnuts did develop significantly smaller leaf lesions than American or backcrossed chestnuts. We conclude that while the detached‐leaf assay may have utility in some chestnut breeding applications, it is not a suitable proxy for the established practice of stem inoculations.     

A dynamic model for water flow in a single tree: evidence that models must account for hydraulic architecture

A model is presented for the dynamics of water flow in a single eastern white cedar tree (Thuja occidentalis L.). The model takes into account the spatial and temporal dependence of the evaporative flux from leaves in the crown. It also accounts for the quantitative hydraulic architecture of the tree, i.e., the model characterizes the tree as a branched catena of > 4000 stem segments in which account is taken of the segment length, diameter, hydraulic resistance, and the total area of leaves attached to the segment. Input values needed to run the model are measurements of evaporative flux, hydraulic conductance of stems versus stem diameter, and leaf and stem water storage capacitances. Output parameters are the spatial and temporal characterization of stem and leaf water potentials, stem and leaf water deficits, sap flow rate, and relative sap velocity. The input and output values of the branched catena model are compared and contrasted to that of an unbranched catena model. It is shown that the branched catena model fits independently measured field parameters better than an unbranched catena model. Close correspondence is found between model predictions and field measurements of shoot water potential, pressure gradients in stems, hysteresis in sap velocity between the lower and upper parts of the tree, and diurnal changes in stem and leaf water deficits. This model is discussed in terms of both the hydraulic architecture of trees and the potential application of the model to questions of tree morphology, ecology, physiology and evolution.     

四川桤木嫩枝扦插育苗技术研究

研究表明 :桤木扦插育苗 ,穗条带顶芽或带 1片叶可显著提高穗条生根率 ,扦插时间则以 5月中旬～ 6月中旬和 9月上旬扦插生根率最高 ,GGR生根剂不同浓度处理后的穗条 (采穗母树 2 .5a生 )其生根率没有显著差异     

遮阳网和肥料种类对铁皮石斛生长的影响

主要研究了遮阳网和肥料种类对铁皮石斛（Dendrobium candidum）生长的影响,选取了株高、茎长、茎粗、叶片数、顶叶叶长、叶宽等6个方面作为铁皮石斛的生长指标。结果表明：5—9月是铁皮石斛茎长的主要生长期,其他月份铁皮石斛的茎长基本处于停止生长的状态,因此,在铁皮石斛大棚栽培过程中,为了提高铁皮石斛的产量和节省种植成本,提高经济效益,可以选择在这段时间进行追施有机肥。研究还表明遮盖1层2针遮阳网对于提高铁皮石斛的茎长效果最好,且追施豆饼肥和花生肥对铁皮石斛的茎长有明显的促进作用,从而可以有效地提高铁皮石斛的产量。     

Leaf and stem morphoanatomy of Petiveria alliacea

Petiveria alliacea is a perennial herb native to the Amazonian region and used in traditional medicine for different purposes, such as diuretic, antispasmodic and anti-inflammatory. The morphoanatomical characterization of the leaf and stem was carried out, in order to contribute to the medicinal plant identification. The plant material was fixed, freehand sectioned and stained either with toluidine blue or astra blue and basic fuchsine. Microchemical tests were also applied. The leaf is simple, alternate and elliptic. The blade exhibits paracytic stomata on the abaxial side, non-glandular trichomes and dorsiventral mesophyll. The midrib is biconvex and the petiole is plain-convex, both traversed by collateral vascular bundles adjoined with sclerenchymatic caps. The stem, in incipient secondary growth, presents epidermis, angular collenchyma, starch sheath and collateral vascular organization. Several prisms of calcium oxalate are seen in the leaf and stem.     

Allometric differences between current-year shoots and large branches of deciduous broad-leaved tree species

Current-year shoots are mostly made of primary tissues, whereas first-order branches comprise mainly secondary tissues. Differences in tissue composition of these units reflect differences in functional design. We compared the allometry of current-year shoots and first-order branches in eight deciduous broad-leaved tree species and examined the functional differences underlying the design of current-year shoots and first-order branches. Allometric relationships of first-order branches tended to be compatible with predictions of the pipe model and elastic similarity model. That is, allometric constants of the relationships between leaf mass and stem diameter at the branch base and between stem diameter and stem mass were 2.0 and 0.33-0.38, respectively, indicating that the functional regulation of stem form of first-order branches can be predicted by the two models. However, allometric relationships of current-year shoots were not compatible with the predictions of the pipe and elastic similarity models. Thus, the allometric constant of the relationship between leaf mass and stem diameter at the base of current-year shoots was larger than 2.0, and the allometric constant of the relationship between stem length and stem diameter of shoots was larger than 1.0 in all species examined. However, current-year shoots had an allometric constant of leaf mass against stem length that was less than 1.0, suggesting a functional demand on shoot design to reduce self-shading. Also, allometric constants of stem length against stem diameter at the shoot base were larger in monopodial species than in sympodial species, whereas allometric constants of leaf mass per shoot against stem length were smaller in monopodial species than in sympodial species. We propose that the allometries of current-year shoots reflect their function as disposable units for temporary leaf arrangement.     

盐分和水分胁迫对落羽杉幼苗的生长量及营养元素含量的影响

采用温室盆栽试验方法 ,研究了不同土壤水分下盐胁迫对 1年生落羽杉实生苗的生长及营养吸收的影响。试验共 12种处理 ,3种水分水平 (W1 ,淹水 ;W2 、W3,土壤含水量分别为田间持水量的 75 %和 2 5 % ) ,每种水分下设 4种盐分处理 (NaCl含量为土壤干重的 0、0 15 %、0 3%和 0 4 5 % ) ,处理时间为 130d。结果表明 :土壤盐分胁迫下落羽杉幼苗的生长及对营养的吸收发生了显著的变化 ,这种变化又因土壤含水量的不同而不同。落羽杉相对高生长、相对地径生长和生物量增量随着土壤盐分浓度的增加和土壤水分含量的减少而减少。在淹水条件下 ,随着土壤盐分浓度的增加 ,落羽杉幼苗根、茎、叶中全N、全P、全Na,以及叶片中的全Ca、全Fe的含量均随着升高 ,而根、茎中的全Fe、全Ca、全Mg含量差异较小。在W2 水分条件下 ,各种盐分处理都在不同程度上增加了根、茎、叶中全N、全Na、全Ca和全Fe含量 ,茎和叶中全P、全K和全Mg含量 ,而根系中的全P、全K和全Mg含量在盐分浓度较高时有所下降。在W3水分条件下 ,各种土壤盐分不同程度地增加了叶片全N、全P和全K含量 ,茎和叶中全Mg和全Ca含量 ,以及根、茎、叶中全Na含量 ,而茎和根中全N、全P和全K含量 ,根、茎和叶中全Fe含量均随着土壤盐分浓度的增加而下降。     

福建省杉木人工林生物量及其分配研究

通过收集福建省杉木林生物量数据,对福建省杉木林生物量及其分配规律进行分析,结果表明,杉木林生物量随年龄增长呈逐渐增加趋势,并以幂方程拟合的效果最好。杉木林叶和枝生物量占总生物量的比例均随年龄增加而呈明显下降趋势,根占总生物量比例的下降趋势则较小,而干占总生物量比例则随年龄增长而明显增加。叶、枝、干生物量占总生物量比例与年龄拟合的效果较好,且最佳方程均为三次方程。根生物量占总生物量比例与年龄拟合的效果则较差。除年龄对根生物量分配比例有极显著负相关外,降水量对根系生物量分配比例亦有显著的负相关。     

新疆杨元素含量与生物量研究

新疆杨(Populus bolleana Lauche)在我国新疆栽培最早,尤以和田、喀什地区生长最好。青海、甘肃、宁夏亦早有栽培,近十余年在陕西、内蒙、山西、辽宁、吉林诸省和北京市也有引种,是我国干旱、半干旱地区农田防护林及人工丰产林的优良树种。为进一步利用新疆杨资源,研究其生物量将具有实际应用价值。     

地被石竹组织培养再生体系的研究

为建立地被石竹组织培养再生技术体系,以地被石竹的叶片和茎段为外植体,MS为基本培养基,对影响再生的生长调节物质进行了研究。结果表明,茎段比叶片易诱导不定芽;叶片在6-BA 2.0 mg/L上不定芽的再生频率较高;茎段在MS 6-BA 5.0mg/L、MS 6-BA 5.0mg/L IBA 0.1mg/L和MS 6-BA 5.0mg/L IAA0.1mg/L上再生频率较高,分别达75.6%6、5.0%和68.5%。     

Hydraulic patterns and safety margins, from stem to stomata, in three eastern U.S. tree species

Adequate water transport is necessary to prevent stomatal closure and allow for photosynthesis. Dysfunction in the water transport pathway can result in stomatal closure, and can be deleterious to overall plant health and survival. Although much is known about small branch hydraulics, little is known about the coordination of leaf and stem hydraulic function. Additionally, the daily variations in leaf hydraulic conductance (K(leaf)), stomatal conductance and water potential (Ψ(L)) have only been measured for a few species. The objective of the current study was to characterize stem and leaf vulnerability to hydraulic dysfunction for three eastern U.S. tree species (Acer rubrum, Liriodendron tulipifera and Pinus virginiana) and to measure in situ daily patterns of K(leaf), leaf and stem Ψ, and stomatal conductance in the field. Sap flow measurements were made on two of the three species to compare patterns of whole-plant water use with changes in K(leaf) and stomatal conductance. Overall, stems were more resistant to hydraulic dysfunction than leaves. Stem P50 (Ψ resulting in 50% loss in conductivity) ranged from -3.0 to -4.2 MPa, whereas leaf P50 ranged from -0.8 to -1.7 MPa. Field Ψ(L) declined over the course of the day, but only P. virginiana experienced reductions in K(leaf) (nearly 100% loss). Stomatal conductance was greatest overall in P. virginiana, but peaked midmorning and then declined in all three species. Midday stem Ψ in all three species remained well above the threshold for embolism formation. The daily course of sap flux in P. virginiana was bell-shaped, whereas in A. rubrum sap flux peaked early in the morning and then declined over the remainder of the day. An analysis of our data and data for 39 other species suggest that there may be at least three distinct trajectories of relationships between maximum K(leaf) and the % K(leaf) at Ψ(min). In one group of species, a trade-off between maximum K(leaf) and % K(leaf) at Ψ(min) appeared to exist, but no trade-off was evident in the other two trajectories.     

Willow stand growth model based on nitrogen productivity

A simple model for willow forest growth during the growing season is presented. The model is based on nitrogen productivity, expressed as the daily above‐ground biomass growth per the amounts of nitrogen in foliage and leaf litter. It is shown that the nitrogen productivity can be expressed as a linear function of the amounts of leaves produced. The model, which also includes allocation of biomass between stem and leaf biomass as well as between foliage and leaf litter biomass, is tested against accurate measurements of the seasonal growth of willow of four different plots. Simulated and measured biomass of stem, foliage, leaf litter and the total above‐ground biomass agreed well for all four plots. The model concept should be useful in nitrogen flux models and as a tool to describe the actual growth of a willow stand, knowing only the annual leaf production and the nitrogen concentrations of foliage during the growing season.