细叶石斛和翅梗石斛花朵赋香成分的GC-MS分析

[目的]本研究明确2种浓香型石斛花朵的香气成分及其含量,探明其香气组成,以期为石斛花的保健开发提供参考。[方法]采用顶空固相微萃取(HS-SPME)结合气相色谱-质谱联用(GC-MS)技术,分析了2种浓香型石斛花朵的挥发性成分。[结果]发现细叶石斛花含挥发性成分52个,翅梗石斛花含挥发性成分35个,主要成分皆为烯烃类。[结论]首次测定了翅梗石斛新鲜花朵的挥发性成分,其特征香气成分为罗勒烯、β-石竹烯和d-柠檬烯。细叶石斛花的特征香气成分为罗勒烯、β-石竹烯、芳樟醇。     

鼓槌石斛不同花期香气成分及盛花期香气日变化规律研究

[目的]本研究明确鼓槌石斛花朵挥发性成分及其释放量变化,阐明其花香气形成的物质基础,为石斛属植物花香研究提供理论基础。[方法]以鼓槌石斛原生种为材料,运用固相微萃取(SPME)结合GC-MS技术测定鼓槌石斛不同花期及盛花期时一天中不同时段花朵挥发性成分及其释放量变化。[结果]从鼓槌石斛花朵释放的花香中共鉴定出花香成分33种,其中,萜烯类15种,酯类7种,醇类6种,芳香族化合物2种,酮类2种,醛类1种;鼓槌石斛花香成分主要为酯类和萜烯类,其释放量占总香气成分的80%以上。鼓槌石斛盛花期花朵随一天中开放时段的不同,香气成分种类和释放量皆呈先上升后下降的趋势,其中,香气种类和释放量均在14:00时达到最高。鼓槌石斛不同花期挥发性成分中的酯类、萜烯类、醛类、醇类、酮类和芳香族化合物的种类和释放量皆呈先上升后下降的趋势,在盛花期达到最高。[结论]本研究明确鼓槌石斛花朵不同花期及盛花期一天中的不同时段挥发性成分及释放量差异明显,乙酸辛酯、β-罗勒烯、α-蒎烯和苯乙醛是影响鼓槌石斛香气的主要物质,为探讨石斛兰香气形成机制和香花型石斛兰育种提供参考。     

不同品系黑老虎各器官精油挥发性成分的GC-MS分析

[目的]为黑老虎林业剩余物合理开发利用提供参考.[方法]2020年10月,在湖南省怀化市通道县黑老虎种植基地选择'大红'紫黑'虎绿'3个品系2年生黑老虎苗作为研究对象,采用水蒸气蒸馏法对各品系根、茎、叶进行精油提取,采用气相色谱-质谱联用法(GC-MS)对其精油挥发性成分进行鉴定.[结果]3个品系黑老虎各器官精油提取率...     

秋石斛在广州的栽培管理

兰科植物中的石斛属(Dentrobium)主产于东南亚及西太平洋各岛,分布于缅甸、泰国、印度、马来西亚新几内亚、印尼、菲律宾、中国南部及澳洲、新西兰等地。在众多的兰科植物中,石斛属可谓最大的一个家族,共有1600多种石斛,大致可分为三类:(1)春石斛,春季开花,属节生花序型(Nobile Type)、花在茎节上开,适于盆花栽培。(2)秋石斛,秋季开花,属顶生花序型(Cane Type)适于切花栽培。(3)野生类的原种石斛。目前,广州地区栽培较普遍价值较高的     

3种石斛属植物类胡萝卜素成分及代谢途径分析

[目的]分析黄色花石斛兰盛开期花瓣中的类胡萝卜素种类和含量,推定石斛属类胡萝卜素合成途径,为探讨黄色花石斛的呈色机理和黄色花育种提供参考。[方法]以花色为黄色的鼓槌石斛、密花石斛和球花石斛的盛开期花瓣和唇瓣为试验材料,采用英国皇家园艺学会比色卡进行花色描述,利用合相色谱串联三重四极杆质谱仪(UPC~2-MS/MS)进行类胡萝卜素定性、定量分析,推测石斛属类胡萝卜素代谢途径。[结果]表明:3种石斛属植物花瓣和唇瓣色系可分为白色系和淡黄-明黄-金黄色系,花瓣和唇瓣中共鉴定出8个类胡萝卜素组分,分别是β-胡萝卜素、α-隐黄质、β-隐黄质、紫黄质、叶黄素、花药黄质、玉米黄质和叶黄素酯化物。定量分析显示:球花石斛白色花瓣中类胡萝卜素含量极少,总量约为52.26μg·g~(-1),随着黄色加深,类胡萝卜素总量逐渐增加,球花石斛金黄色唇瓣中的类胡萝卜素总量最高,达到3 810.89μg·g~(-1)。密花石斛淡黄色花瓣中以叶黄素为主;球花石斛和密花石斛金黄色唇瓣中主要是α-隐黄素、叶黄素和叶黄素酯化物;明黄色鼓槌石斛花瓣中以玉米黄质、花药黄质和叶黄素为主。[结论]α-胡萝卜素及其衍生物是淡黄色和金黄色石斛花瓣中的主要类胡萝卜素成分,而β-胡萝卜素及其衍生物是明黄色石斛花瓣的主要类胡萝卜素成分。结合类胡萝卜素代谢途径,推测通过调控LCYE基因的表达,可实现黄色花石斛的花色定向改良。     

长沙地区18个桃花品种的观赏性评价

[目的]研究观赏桃在湖南省长沙地区的观赏特性及其价值,为长沙地区引种栽培桃花提供科学依据.[方法]调查了湖南省森林植物园桃花园中18个观赏桃品种的花期物候期及其花色、花量、花瓣数、花冠直径(盛开时花朵自然张开的直径)、雄蕊、雌蕊、萼片数等观赏性指标,采用层次分析法对相关观赏性指标进行赋分评价.[结果]18个观赏桃品种的...     

鹿角杜鹃开花过程中挥发性成分的变化

利用顶空固相微萃取-气相色谱质谱法,对鹿角杜鹃Rhododendron latoucheae花朵在花蕾期、半开放期、盛开期及凋落期4个开花期的挥发性成分进行了定性和相对定量分析,研究了鹿角杜鹃花香成分的种类和变化情况.结果表明,在鹿角杜鹃花朵开放的4个时期中共检测出37种挥发性成分,这些挥发性成分种类在开花过程中呈升高...     

河南野生忍冬叶、花、果挥发性成分比较

为比较河南野生忍冬叶、银花子(果)、金银花(花)挥发性成分,采用挥发油提取器从河南产的金银花、银花子、忍冬叶中提取挥发性物质,并通过GC-MS联用技术对挥发性成分进行分析鉴定,用色谱峰面积归一化法计算各成分的相对含量。结果表明:银花子、金银花、忍冬叶挥发性成分中,酯类含量大小排序为银花子忍冬叶金银花;醛酮醇含量大小排序为金银花忍冬叶银花子;芳香族类含量大小排序为忍冬叶银花子金银花;烷烃类成分含量银花子远高于金银花、忍冬叶;三者都含有芳樟醇,并且含量都比较高。银花子与金银花、忍冬叶的挥发性成分有明显差异,三者的临床应用应有所不同;芳樟醇是忍冬叶、银花子、金银花共有功效的物质基础。建议今后加强银花子活性成分及药理作用研究。     

不同温度处理对春石斛花期及品质的影响

以春石斛栽培品种‘猫眼’石斛(Dendrobium Gatton Sunray)为试验材料,研究花芽分化后不同温度处理对其花期及品质的影响。结果表明,经20、24和28℃升温处理,从低温诱导花芽分化至开花时间分别为121、102和88 d,较对照提前26～59 d。20℃处理的春石斛在春节后约3周开花,始花至末花期持续时间最长(37 d),适宜的低温有利于延长花期。春节期间,24℃处理的春石斛花苞即将开放,28℃处理的正值盛花期,两温度处理所需时间短。24℃处理的春石斛,其花横径、纵径、单茎花朵数、开花假鳞茎数、总花朵数及开花整齐度分别为5.50 cm、4.77 cm、9.20朵、4.13条、37.96朵、82.22%,开花品质和观赏效果最佳。     

5种石斛花器官特性及人工授粉研究

对石斛属翅萼石斛(D. cariniferum Rchb. f.)、棒节石斛(D. findlayanum Par.et Rchb. f.)、玫瑰石斛(D. crepidatum Lindl. ex Paxt.)、晶帽石斛(D. crystallinum Rchb. f.)、黄花石斛(D. dixanthum Rchb. f.)5个种的花器官形态和人工授粉技术进行研究。结果表明,不同种石斛花期不一致,花期长的盛花期长,花期短的盛花期短;同一种石斛受温度影响开花时间不一样。参试石斛合蕊柱长、宽和粘液厚度全部大于花粉粒,同一种石斛合蕊柱能够容纳下本种的花粉粒,粘液覆盖花粉粒。翅萼石斛开花第5～10 d授粉效果最好,棒节石斛、玫瑰石斛、晶帽石斛和黄花石斛开花第1～4 d授粉效果好;翅萼石斛和棒节石斛异株异花授粉效果最好,玫瑰石斛、晶帽石斛和黄花石斛三种授粉方式坐果差异不明显。花期对石斛坐果率的影响较大,花期长的授粉期限长,花期短的授粉期限短,石斛人工授粉最好在盛花期进行。     

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.