外源K-IBA对北美香柏扦插生根和内源激素含量变化的影响

以北美香柏Thuja occidentals L.2年生枝条为材料,采用3-吲哚丁酸钾盐(K-IBA)3个浓度(3 000、6 000、10 000 mg/L)处理扦插生根试验,清水处理为对照。扦插60天后统计插穗生根率、平均根长、最长根长、平均生根数。扦插后每隔15 d从6 000 mg/L K-IBA与对照处理插穗的基部取样,测定生根过程中内源激素吲哚乙酸(IAA)、赤霉素(GA)、脱落酸(ABA)和玉米素(ZT)含量的变化。结果表明:外源K-IBA对北美香柏扦插生根有促进作用,其中6 000 mg/L K-IBA的处理效果最好,其生根率为87.78%、生根数22.33根、平均根长12.33 mm、最长根长75.20 mm,显著高于对照。与对照相比,6 000 mg/L K-IBA处理组的内源IAA含量、GA含量提高,而内源ABA、ZT含量下降,促使生根率提高。在北美香柏扦插生根过程中,K-IBA处理调节了内源激素IAA、GA、ABA和ZT含量的变化,而内源激素的动态变化,共同调控插穗不定根的形成。     

毛竹花期不同器官内源激素含量的变化

用酶联免疫法测定未开花毛竹和开花毛竹叶、花、枝、秆和鞭中内源激素吲哚乙酸(IAA)、赤霉素(GA3)、脱落酸(ABA)和玉米素核苷(ZR)的含量,分析开花毛竹内源激素分布和含量的变化与花形态分化的关系.结果表明:与未开花毛竹相比,成花期(6月中旬)开花毛竹叶、枝和秆中的IAA含量显著降低,枝的ABA含量也显著降低,而秆的ZR含量显著升高;扬花期(7月中旬)开花毛竹枝中的IAA含量显著降低,而GA3含量则显著升高.内源激素在开花毛竹各器官中的分布规律:IAA为秆＞鞭＞枝＞花,GA3为花＞鞭＞枝＞秆,ZR为花＞枝＞秆＞鞭,ABA为秆＞枝＞花＞鞭.二级枝中IAA含量显著低于一级枝,而其GA3和ZR的含量高于一级枝.IAA、GA3和ABA在竹杆中的含量呈向基性增加,而ZR则呈向基性减少.在成花期和扬花期ABA、ZR和GA3所占比例高于未开花毛竹,高比例的ABA、ZR和GA3和低比例的IAA可能促进毛竹花的发育.     

生长调节剂对南方红豆杉大孢子叶球和内源激素的影响

【目的】研究不同生长调节剂对南方红豆杉叶片内源激素含量的动态变化和开花特性的影响,为优化栽培方式、提高种子产量提供参考依据。【方法】以13年生南方红豆杉雌株为研究材料,连续3次叶面喷施不同种类和质量浓度的生长调节剂,通过测定叶片内源激素的动态变化和统计标准枝上生殖枝比例和大孢子叶球数量,分析不同生长调节剂对南方红豆杉的影响规律。【结果】叶面喷施1 500 mg·L~(-1)多效唑、450 mg·L~(-1)矮壮素和2 000 mg·L~(-1)复硝酚钠均能有效促进南方红豆杉的大孢子叶球数量(P 0.05)。三者降低了叶片中GA3含量(除9月上旬的450 mg·L~(-1)矮壮素处理外),提升了9月上旬ZR含量,同时降低了IAA含量,且均达显著水平。另外,1 500 mg·L~(-1)多效唑升高了8月上下旬、9月上旬叶片中ABA/IAA、ABA/GA3、ZR/IAA、ZR/GA3比值;450 mg·L~(-1)矮壮素则增加了9月上下旬ABA/IAA、ZR/IAA和ZR/GA3以及8月、9月的ABA/GA3比值;2 000 mg·L~(-1)复硝酚钠提升了8月下旬、9月上旬的ABA/IAA、ZR/GA3,9月上旬的ZR/IAA和9月下旬的ABA/GA3比值,且均达显著水平。【结论】叶面喷施1 500 mg·L~(-1)多效唑、450 mg·L~(-1)矮壮素和2 000 mg·L~(-1)复硝酚钠均能显著增加南方红豆杉的大孢子叶球数量,这可能是由于处理改变了内源激素的含量和比值,特别是增加了ZR含量和ABA/IAA、ABA/GA3、ZR/IAA、ZR/GA3比值,降低了IAA和GA3含量。在生产中,可以据此结论进行适当的栽培管理。     

厚竹群落孕笋成竹期内源激素动态变化与调控作用

为了研究厚竹群落在孕笋成竹期内源激素的分布特征和动态变化规律,探讨内源激素及其相互作用对厚竹孕笋成竹的影响,采集不同时期的竹鞭、竹笋和母竹样品,通过酶联免疫吸附法(ELISA),测定吲哚-3-乙酸(IAA)、赤霉素(GA)、玉米素核苷(ZR)和脱落酸(ABA)的质量分数,通过方差分析和多重比较方法分析内源激素质量分数及其比值的差异。结果表明:厚竹群落中IAA和ABA质量分数显著高于ZR和GA,但IAA和ABA之间及GA和ZR之间的差异因生长系统及发育期不同而程度不同。笋芽膨大期,竹鞭、竹笋和母竹中内源激素质量分数均是ABA IAA GA ZR,竹鞭中促进生长类激素偏高,ABA显著偏低,冬笋中ZR和GA质量分数占内源激素总质量分数的比例显著高于竹鞭和母竹。竹笋生长期,竹鞭和母竹中是ABAIAA ZR GA,春笋中是IAA ABA ZR GA;春笋中的ZR质量分数及所占比例显著高于竹鞭,ABA的质量分数及所占比例显著低于竹鞭,GA/IAA值显著高于母竹;母竹中的内源激素总量明显偏多,并且是促进生长类激素比例较高,ZR/GA值显著高于竹鞭。新竹长成期,3个生长系统中均是ABA IAA ZR GA;母竹中IAA质量分数显著偏低,ABA质量分数显著偏高。在孕笋成竹过程中,母竹和竹鞭中的IAA和ABA动态变化规律刚好相反。在新竹个体发育中,GA/ABA和GA/IAA值逐渐降低,其他激素间的比值均呈抛物线变化。综合分析得出:厚竹群落中IAA和ABA的质量分数显著偏高;在孕笋成竹过程中,不同生长系统及不同内源激素的分布特征和动态变化规律不同;内源激素及相互间的协同或拮抗作用对孕笋成竹有显著调控作用,相对较高的IAA和ZR质量分数可能是竹壁增厚的原因之一。     

红锥花芽分化过程及相关激素含量的变化

为揭示红锥（Castanopsis hystrix）花芽分化过程及激素含量变化,以红锥嫁接植株花芽为试材,采用石蜡切片法观察花芽形态,采用酶联免疫法测定花芽中激素含量。结果表明,红锥花芽分化可分为4个阶段：冬前花序原基分化期（阶段Ⅰ）、冬后花序原基分化期（阶段Ⅱ）、花簇苞片原基分化期（阶段Ⅲ）和花簇原基分化期（阶段IV）。在花芽分化过程中,高水平ABA、IAA、ZT、ABA/GA3、ABA/IAA和ZT/GA3比值,较高水平ZT/IAA比值,低水平GA3、GA3/IAA比值有利于红锥冬前花序原基分化;高水平ABA/IAA、ZT/IAA和GA3/IAA比值,较高水平GA3、ABA,低水平IAA、ZT、ABA/GA3和ZT/GA3比值有利于红锥冬后花序原基分化;高水平ZT、ZT/IAA比值,较高水平GA3、GA3/IAA比值,低水平ABA、IAA、ABA/GA3、ABA/IAA和ZT/GA3比值有利于花簇苞片原基分化期;高水平IAA,较高水平GA3、ZT、ZT/IAA和GA3/IAA比值,低水平ABA、ABA/GA3、ABA/IAA和ZT/GA3比值有利于花簇原基分化期。在整个花芽分化时期...     

不同秆形好运竹植株体内源激素分布规律研究

采用酶联免疫法对不同秆形的好运竹各部位吲哚乙酸(IAA)、赤霉素(GA3)、玉米素核苷(ZR)、脱落酸(ABA)进行测定。结果显示:IAA在直秆竹小枝和秆中的含量较高,GA3和ZR在鼓秆竹小枝和秆中的含量较高,ABA在各秆形中含量差异不显著。各激素在植株叶部的含量较高。ZR和ABA在竹秆中分布呈向基性减少趋势,IAA和GA3在竹秆中部含量较高。     

板栗二次花芽分化过程中激素含量变化

为给激素调控板栗二次结实技术奠定基础,以具有二次结实性板栗品种"遵玉"为试验材料.采用高效液相色谱法(HPLC)测定其二次花芽分化过程中内源激素含量,研究其二次花芽分化与激素含量的关系.研究结果表明,在二次花芽分化整个过程中,花芽中的玉米素(ZT)和脱落酸(ABA)含量是显著升高的.赤霉素(GA3)和生长素(IAA)含量是显著降低的,说明高水平的ZT和ABA以及低水平的GA3和IAA有利于花芽的分化.从激素间的平衡关系看,ZT/GA3、ZT/IAA,ABA/GA3和ABA/IAA的高比值有利于板栗花芽的分化.     

~(60)Co-γ对海州常山扦插过程内源激素含量的变化影响

以海州常山(Clerodendrum trichotomum Thumb)1年生休眠枝条为材料,采用60Co-γ射线(剂量15Gy)处理扦插插穗,未经辐射处理为对照。于扦插后40d、47d、54d、64d、74d、84d和104d从辐射与对照处理插穗基部皮部取样,测定生根过程中内源激素生长素(IAA)、赤霉素(GA3)、脱落酸(ABA)和玉米素(ZR)含量的动态变化。结果显示:60Co-γ射线抑制海州常山扦插生根。与对照相比,15Gy的60Co-γ射线辐射处理组的内源IAA含量、ABA含量和ZR含量均在不定根诱导和形成期间多上升,GA3含量、IAA/ABA,GA3/ABA,ZR/ABA比值含量降低,IAA和ZR含量谷值推后到来。60Co-γ辐射处理提高不定根形成期内源ABA含量,从而IAA/ABA,GA3/ABA,ZR/ABA比值降低,这是插穗生根推迟的主要原因。     

AgNO3处理下银杏幼胚愈伤组织的形成和激素变化

采用石蜡切片技术和酶联免疫吸附法(ELISA),以银杏幼胚为外植体,添加0,1和5 mg/L AgNO3作处理,观察21 d内愈伤组织的形成过程,测定内源激素吲哚乙酸(IAA)、保幼激素类似物(ZR)、赤霉素(GA)和脱落酸(ABA)的变化,分析AgNO3对银杏幼胚愈伤组织分化潜能的影响。结果表明:根据解剖结构愈伤形成可分为4个阶段。第1阶段(0~7 d),IAA升高,ABA降低,表皮细胞启动脱分化。第2阶段(≥7~11 d),4种激素浓度均升高,愈伤组织和细胞团初步形成。第3阶段(≥11~16 d),GA、ABA大幅降低,细胞团大量形成。第4阶段(≥16~21 d),ABA骤降、GA迅速上升,愈伤组织和细胞团增殖。1 mg/L AgNO3处理下分生细胞团种类最多,其次为5mg/L处理,0 mg/L处理最少。研究认为,银杏幼胚愈伤组织具有较强的分化潜能,AgNO3能影响其内源激素的平衡,调控分化方向。     

AgNO_3处理下银杏幼胚愈伤组织的形成和激素变化

采用石蜡切片技术和酶联免疫吸附法(ELISA),以银杏幼胚为外植体,添加0,1和5 mg/L AgNO3作处理,观察21 d内愈伤组织的形成过程,测定内源激素吲哚乙酸(IAA)、保幼激素类似物(ZR)、赤霉素(GA)和脱落酸(ABA)的变化,分析AgNO3对银杏幼胚愈伤组织分化潜能的影响。结果表明:根据解剖结构愈伤形成可分为4个阶段。第1阶段(0~7 d),IAA升高,ABA降低,表皮细胞启动脱分化。第2阶段(≥7~11 d),4种激素浓度均升高,愈伤组织和细胞团初步形成。第3阶段(≥11~16 d),GA、ABA大幅降低,细胞团大量形成。第4阶段(≥16~21 d),ABA骤降、GA迅速上升,愈伤组织和细胞团增殖。1 mg/L AgNO3处理下分生细胞团种类最多,其次为5mg/L处理,0 mg/L处理最少。研究认为,银杏幼胚愈伤组织具有较强的分化潜能,AgNO3能影响其内源激素的平衡,调控分化方向。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.