两种长春花体内黄酮含量的研究

对野生及露地栽培生境中生长的红长春花和白长春花不同部位中总黄酮含量进行比较研究,研究结果显示:1)长春花各部位中总黄酮含量从高到低为果(含种子)、叶片、花、茎、根;2)野生白长春花体内总黄酮含量低于栽培白长春花;3)野生红长春花体内总黄酮含量与露地栽培红长春花的含量相接近;4)红长春花体内总黄酮含量高于白长春花;5)两种长春花在茎和叶片在不同高度上的总黄酮含量有所差异。长春花体内黄酮物质的这种分布特点将为下一步园林花卉的引种驯化工作提供理论支持。     

蔓长春花与花叶蔓长春花水分生理特性的比较研究

通过对蔓长春花与花叶蔓长春花水分生理特性的研究,结果表明:蔓长春花与花叶蔓长春花春季的水分利用率分别为3.883和1.598 μmol CO2·mmol-1 H2O;夏季分别为0.948、0.785 μmol CO2·mmol-1 H2O;秋季分别为3.894、3.093 μmol CO2·mmol-1 H2O。两者在秋季的水分利用率均高于春季,春季高于夏季,且在三季中蔓长春花的水分利用率均大于花叶蔓长春花。回归分析表明,春、夏、秋三季,气孔导度和叶面水汽压亏缺是影响蔓长春花和花叶蔓长春花水分利用率的主要因素。综合分析认为,在夏季适当增加空气相对湿度和降低温度可提高蔓长春花和花叶蔓长春花的水分利用率。     

家庭盆栽长春花

长春花又名五瓣梅，为夹竹桃科，长春花属植物，长春花株形整齐，叶片长椭圆形，深绿具光泽，花腋生，花瓣五枚平展，酷似梅花，长春花的嫩枝顶端每长出两叶片，其叶腋间即冒出两朵花，因此它的花朵特别多，花期特别长，花势繁茂，从春到秋开花从不间断，所以有日日春、天天开之美名。长春花原产西印度，性喜高温高湿，耐半阴，生长最适温度为20至33摄氏度，在我国南方各省可露地栽培，在长江以北地区，多作盆栽欣赏。     

长春花不同花色品种呈色的关键理化性质分析

[目的]研究长春花不同花色的形成与花瓣细胞内重要理化环境的关系,旨在更好地理解长春花花色的形成机理,从而为新花色品种的培育提供理论依据.[方法]以6个不同花色品种长春花的花瓣为试材,对各品种的花色表型、花瓣解剖结构、花瓣细胞液pH值、花瓣中10种金属元素的含量和花色素的组分与含量进行测定,并对各品种间的差异化表征及其与...     

优良地被植物蔓长春花

蔓长春花（ＶｉｎｃａｍａｊｏｒＬ．）又名攀缠长春花，缠绕长春花、长春蔓。原产地中海沿岸、印度、热带美洲。它适应性强，生长迅速，繁殖简单，可粗放管理，常绿，病虫害少，是值得在园林绿化中推广的花、叶皆优的地被植物。一、形态特征蔓长春花为夹竹桃科、蔓长春花...     

长春花花叶病病原物的分离和鉴定

长春花病原物采白海南省琼海市博鳌镇和广东省广州市星海公园,症状表现为系统花叶与畸形,对其进行染病外植体组织培养、鉴别寄主反应、传播方式鉴定、病毒粒体形态观察和血清学反应及病叶双链RNA(dsRNA)分析.引起长春花花叶病的病原物鉴定为黄瓜花叶病毒(cucumber mosaic virus,CMV),克隆该病毒分离物外壳蛋白基因核苷酸序列,并对该核苷酸序列进行生物信息学分析,结果显示侵染我国长春花引起长春花花叶和畸形的CMV分离物应初步划归在CMV IB亚组.     

不同基质与NAA浓度对小蔓长春花扦插生根的影响

以小蔓长春花当年生枝条为试材,采用蛭石、河沙、园土等扦插基质,不同浓度的NAA对小蔓长春花插条进行了扦插生根试验,结果表明：以200mg/L NAA蘸根,以河沙为基质最适宜小蔓长春花扦插生根,生根率达89%;平均生根数4．67条;平均根长3．45cm。NAA各处理在生根长度、生根条数上均较空白对照显著增加。     

长春花的栽培及观赏利用

简单阐述长春花的形态特征及介绍目前常见的栽培品种分类,对其栽培管理技术中诸如繁殖育苗、栽培管理、痛虫害防治等进行了简单论述,并根据长春花的形态特征及习性提出适合于在不同场所进行观赏利用的途径。     

重阳木丛枝病类菌原体（MLO）传染长春花的研究

重阳木丛枝病普遍发生在我国南方各省,尤其安徽、湖北一些地区危害严重。1983年作者用电镜证实了重阳木丛枝病为类菌原体病害。本病在国外尚无报道。在传病试验中证实了感病植株病皮能嫁接传病。树木感染MLO病害后,其病原在感病植株中分布局限且浓度较低。长春花是多年生草本植物,植物MLO病原能在长春花内大量繁殖,成为研究树木MLO病害的理想试验植物。1988年试验证实泡桐丛枝病MLO病原可由南方菟丝子传染到长春花上,表现典型丛枝黄化及花变叶病状。本文将报道用南方菟丝子传染重阳木丛枝病MLO到长春花上,并回接成功。     

泡桐丛枝病感病指示植物的病理变化——Ⅰ.同工酶、酚及酚相关酶

以感染泡桐丛枝病类菌原体的长春花和健康长春花的叶片为材料,对其过氧化物酶、酯酶、谷草转氨酶、总酚及酚相关酶进行分析测定。结果表明,与健株相比较,病株中三种同工酶的活性降低了,某些酶带颜色变浅或消失:总酚含量与绿原酸含量有所增加:多酚氧化酶与苯丙转氨酶活性明显增强,并讨论了这些变化与类菌原体致病存在的可能关系。     

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.