不同生长类型云南红豆杉林木枝叶的紫杉烷含量测定

从云南红豆杉天然林在云南分布区的29个县中选择98株林木作样株,又从该树种主要种植地的云南红豆杉人工林和天然林无性系扦插苗中随机选出其林木51株,苗木54株,共计203株。以其小枝叶为样品,检测紫杉醇、10-DAB(10-去乙酰巴卡亭Ⅲ)等6种紫杉烷类化合物的含量。以此估计的云南红豆杉林木枝叶中的紫杉烷平均含量为0.051 40%,95%置信区间为0.045%~0.058%;其平均值的排序为人工林(0.087 0%)>扦插苗(0.051 1%)>天然林(0.033 0%),3种类型云南红豆杉林木枝叶所含6种紫杉烷类的平均值排序为:10-DAB(0.026 3%)>10-DAET(0.007 0%)>紫杉醇(0.006 2%)>巴卡亭Ⅲ(0.005 4%)>三尖杉宁碱(0.005 0%)>7-差向紫杉醇(0.001 6%)。检测中发现了10-DAB含量达0.205 9%和紫杉烷类合计值达0.344 8%的云南红豆杉单株,超过了巴卡亭Ⅲ含量0.2%的世界最高纪录。     

云南红豆杉优树选择研究

在云南红豆杉天然林分布区,以及3个重点栽培区的云南红豆杉人工林中,经广泛布点调查初选,采集初选林木小枝叶样品,进行紫杉醇、10-去乙酰巴卡亭Ⅲ(10-DAB)、巴卡亭Ⅲ、三尖杉宁碱(cephaloma-nine)、10-去乙酰-7-差向紫杉醇(10-DAET)、7-差向紫杉醇等6种紫杉烷类含量的检测,并通过扦插繁殖培育出初选优树的扦插苗栽培于立地条件一致的优树汇集区内,经2~2.9年再检测苗木的紫杉烷含量及测定苗木的生物量。以其紫杉烷含量、生物量、紫杉烷产量(紫杉烷含量×生物量)为云南红豆杉优树的评选指标,依此在云南全省的云南红豆杉天然林中评选出优树38株(1级8株、2级11株、3级19株),在云南红豆杉人工林中评选出优树17株(1级4株、2级13株),其选择增益很显著。根据优树的分布,在云南全省寻找到10个云南红豆杉紫杉烷高含量的种源区,这是以林木枝叶紫杉烷的含量为主要选择对象,进行云南红豆杉优树选择的一个新尝试。     

中国红豆杉中主要紫杉烷类物质的分布研究

对中国红豆杉[Taxus chinensis(Pilg.)Rehd.]中的紫杉烷类化合物紫杉醇及两种重要前体巴卡亭III(B III)和10-脱乙酰巴卡亭III(10-DAB)的分布进行了研究.结果表明,紫杉醇的含量在同一棵树中的分布依主干皮、根皮、侧枝树皮、种子、须根、嫩枝、叶的次序递减,并发现侧枝茎中紫杉醇在横截面方向呈梯度分布,且紫杉醇含量最高部位是在次生木质层.10-DAB和B III在叶中含量最高,在须根中含量最低,叶子中10-DAB的含量达0.02%～0.03%,高于B III的含量.在2～3 a生的小树枝、叶中未检测到紫杉烷类物质,提示其合成可能与植株发育有关.紫杉醇在30 a 树龄的当年生嫩叶中春季高于秋季,而10-DAB在当年生和多年生的叶中积累都较多,且秋季比春季含量高.     

云南红豆杉枝叶的6种紫杉烷类物质含量及其相关性分析

对天然生长、人工栽培的云南红豆杉林木及云南红豆杉扦插苗203个小枝叶样的6种紫杉烷类物质含量进行了检测,进而对此6种紫杉烷类物质含量间的相关关系进行了分析.结果表明:云南红豆杉枝叶中的6种紫杉烷类物质总体含量较高,其合计含量达0.514 g·kg-1,其中以10-DAB的含量最高,占其总量的51.36 %,而紫杉醇的含量排在第三,为总量的12.06 %;云南红豆杉枝叶的6种紫杉烷类物质的含量间,均为正相关关系,多数相关系数都在α=0.01的水平上显著.据此,建立了云南红豆杉枝叶中10-DAB及紫杉醇的含量与其他5种紫杉烷类物质含量间的直线回归方程,用以预测其他5种紫杉烷类物质的含量.     

云南红豆杉枝叶紫杉烷含量在林分间与单株间差异的分析

对13个云南红豆杉天然林分所选的39株林木枝叶的6种紫杉烷含量,在林分间和林分内单株间的差异,进行了方差分析,其结果表明,枝叶中的6种紫杉烷总含量,或是单一的紫杉醇、10-DAB、10-DEAT的含量,在林分间的差异均达到极显著的水平,而在林分内的单株间差异则不显著。说明云南红豆杉枝叶紫杉烷含量性状的群体遗传力是显著的和稳定的。这一结果,为云南红豆杉药用成分高含群体选择提供了依据。     

红豆杉属植物中紫杉烷类物质含量影响因素综述

紫杉烷是以抗癌药物紫杉醇为首的具有五甲基十五碳烯骨架的一类二萜类化合物的总称,多数为红豆杉属植物中的主要成分。其中有些紫杉烷可以作为半合成紫杉醇的原料,有些具有多方面的药理活性。从不同种源、不同性别及年龄、不同部位以及环境因子等方面对红豆杉属植物中紫杉烷类物质含量的影响因素进行概述,进而为人们对野生东北红豆杉资源合理、有效、充分的利用提供理论基础。不仅为紫杉醇大量生产提供解决途径,又可以避免野生资源遭到毁灭性的破坏。     

产紫杉醇内生真菌研究的回顾、进展及趋势

自1993年在太平洋紫杉中发现产紫杉醇的内生真菌以来,其寄主植物除红豆杉属外,在罗汉松属、榧树和松柏科植物等26种植物中亦有分布。目前,发现的产紫杉醇的内生真菌有219株,广泛分布在55个属中。内生真菌的鉴定采用基于DNA条形码的分子鉴定为主,在此基础上进行形态学鉴定。紫杉醇的鉴定和产紫杉醇内生真菌的筛选方法从薄层层析分析,逐步发展为质谱和高效液相色谱为主,以及以核磁共振,基于紫杉醇合成途径关键基因的PCR法鉴定和细胞毒性分析为辅的综合性鉴定和筛选方法。紫杉醇含量分析主要应用高效液相色谱法,竞争性抑制酶免疫分析也可用于分析紫杉醇的含量,但其稳定性和可靠性需要进一步验证。通过产紫杉醇的内生真菌实现紫杉醇的规模化生产,除需要筛选高产菌株外,还需要运用代谢工程,基因组学和基因工程方法和技术。     

红豆杉枝叶干燥及贮存工艺研究

研究了红豆杉（Taxus chinensis）鲜枝叶采收后的干燥、贮存方式及贮存期限对枝叶中有效 产物10-DAB Ⅲ和紫杉醇含量的影响，结果表明：（1）采用不同干燥方法处理时，红豆杉样品中10DAB Ⅲ、紫杉醇含量具有显著差异（P<0.05）。同一温度干燥时，干燥时间越长，样品中 10-DAB Ⅲ和紫 杉醇含量下降越快；在一定温度范围内（约25~100℃）干燥时，干燥温度越高，则干燥时间越短。产物 含量与枝叶干燥时间和温度呈负相关；（2）贮存期间发生霉变的红豆杉鲜枝叶和枝叶干粉其产物含量均 会逐渐降低，且新鲜枝叶中产物含量降低较快；（3）贮存期间红豆杉枝叶中10-DAB Ⅲ产物较紫杉醇不 稳定，更易受环境条件影响而降解。（4）长期贮存的红豆杉枝叶的含水量应控制在 10% 以内，贮存环境 应该阴凉、干燥，且贮存时间不宜超过 1 a。     

紫杉链格孢1011菌株产紫杉烷类物质的分离纯化和结构鉴定(英文)

植物体内普遍存在内生真菌,它们可以产生与宿主相同或相似的生理活性物质。通过微生物发酵产生生理活性物质可以为解决能源短缺和寻找替代能源开辟一条新途径。作者初步探讨了分离和纯化高产菌株以及对其发酵代谢产物的结构鉴定的方法。采用溶剂提取法、薄层色谱法和柱色普法,对从东北红豆杉(T.cuspidataSieb.etZucc.)上分离筛选出的高产紫杉烷类物质紫杉链格孢(Alternariaalternatavar.taxi1011Y.XiangetLUAn-guo)1011菌株的发酵产物进行分离纯化,提取了一个化合物Ⅰ。经紫外扫描、红外扫描、质谱、核磁共振等方法鉴定,确定该化合物为紫杉烷类二萜Ⅲ型化合物。图1表2参12。     

红豆杉枝叶中产物分布研究

研究了南方红豆杉枝叶中叶片、树皮、嫩枝和木质部的生物量比例,以及各部位中主要有效成分紫杉醇和10-DABⅢ的含量分布情况。实验结果表明:红豆杉枝叶中叶片的生物量约占30%,叶片中累积的有效产物量最高(约占总量的70%);树皮含量次之,杂质最少;红豆杉枝叶中木质部的生物量最多(占46%),累积的产物最少(约占总量的5%)。叶片是红豆杉枝叶中提取紫杉醇等产物的最有效部位。     

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.