红锥ISSR—PCR扩增体系的优化

对广西红锥种群的DNA进行提取和ISSR—PCR扩增体系进行优化。分析了退火温度、模板DNA浓度、Mg^2＋浓度、dNTPs浓度、TaqDNA聚合酶用量对反应结果的影响。红锥ISSR—PCR分析较适宜的扩增体系是：25μL PCR反应体积中，buffer（10mM Tris-HCl，pH9．0，50mM KCl，0．1...     

杠柳ISSR引物的筛选及PCR反应体系的优化

为建立适用于杠柳ISSR分子标记研究的扩增体系,进一步利用ISSR标记研究杠柳遗传多样性,探讨了杠柳ISSR分子标记中的各影响因素,分别对河北11个不同地区杠柳基因组DNA进行PCR扩增,在Taq MasterMix(康为世纪)基础上对影响ISSR-PCR扩增结果的模板DNA浓度、循环次数、引物退火温度进行梯度筛选。结果表明:在100条通用引物中共筛选出34条扩增条带清晰、整齐的ISSR引物;确立了适合杠柳ISSR分子标记的反应体系:总反应体积25μL,其中Taq MasterMix(含DNA聚合酶、MgCl_2、dNTPs、反应缓冲液以及稳定剂)12.5μL,模板DNA 1μL(70ng/μL),正向引物和反向引物各1μL(10μmol/L)。该体系的确立为今后利用ISSR技术对杠柳种质资源的遗传多样性分析奠定了技术基础。     

光皮树ISSR-PCR扩增条件和反应体系优化

以光皮树基因组DNA为材料，采用单因素实验，测试了退火温度、模板用量、dNTP浓度、Taq酶用量、Primer浓度、Buffer用量和Mg^2＋浓度等因素对ISSR-PCR的影响。优化的反应体系和条件：总体系为25μL，引物0．2μmol／L、模板20ng、Mg^2＋ 2．5mmol／L、Taq酶0．5U、dNTP为0.1mmol／L和Buffer为2.5μL。扩增程序：94℃预变性5min，1个循环；94℃变性50s，52℃退火1min，72℃延伸1．5min，40个循环；72℃后延伸10min，1个循环。该体系的建立为今后利用ISSR进一步研究光皮树遗传连锁图谱构建、遗传多样性、种质资源鉴定和基因定位奠定了技术基础。     

竹子SRAP-PCR体系的建立与优化

首次报道竹类植物SRAP-PCR反应体系的建立与优化。以竹叶总DNA为模板,经过大量实验,建立和优化了竹子SRAP-PCR的50μL反应体系,20 ng模板DNA,2.0 mmo1/L Mg2+,175μmol/LdNTPs,0.2μmol/L引物,1.5 UTaqDNA聚合酶,5μL10×buffer,退火温度52℃为最优反应组合。该反应条件下扩增条带清晰,多态性丰富。     

钩栗ISSR-PCR反应体系的建立与优化

本研究以钩栗叶片为实验材料,采用单因素和L16(45)正交实验探讨了DNA模板用量、Mg2+浓度、引物用量、Taq DNA聚合酶、d NTP用量以及不同退火温度对钩栗ISSR-PCR扩增的影响,建立了钩栗ISSR-PCR反应体系。研究结果显示,优化后的最佳反应体系为,20μL反应总体系中,含30 ng模板DNA,3 mmol/L Mg2+,0.4 mmol/L d NTPs,0.75 U Taq DNA聚合酶,0.3μmol/L引物;对钩栗DNA样品材料进行ISSR-PCR扩增体系的检测结果显示,该优化体系扩增的产物条带清晰,稳定性高,本研究为钩栗种质ISSR分子标记遗传结构分析提供技术基础。     

均匀设计优化兴安落叶松ISSR-PCR反应体系

采用均匀设计方法,对影响兴安落叶松ISSR-PCR体系的MgCl2、dNTPs、引物、TaqDNA聚合酶和模板5个组分的浓度进行了U16(45)和U12 (35)两轮优化,建立了适合于兴安落叶松的ISSR-PCR反应体系.该优化的20μL反应体系包含MgCl2 3.0 mmol/L、dNTPs 0.15 mmol/L、引物0.5μmol/L、TaqDNA聚合酶1.0U、模板20ng/20μL.并进一步进行梯度退火试验,找到了最适的兴安落叶松ISSR退火温度为56.5℃.利用所确立的体系对部分兴安落叶松种质进行扩增的结果清晰可靠,多态性好.     

云南松SSR—PCR反应体系的优化研究

本项研究以云南松实生苗幼嫩针叶为材料,采用单因素试验设计,分析云南松SSR—PCR扩增反应体系中各组分对扩增结果的影响,并进一步采用正交试验设计对SSR—PCR扩增反应程序进行优化。结果表明,在15μL SSR-PCR反应体系中包括,1×TaqPCRBuffer,模板DNA用量30ng,Taq聚合酶用量1．0U,0．2mmol L-1dNTPs,3．0mmol·L-1Mg2＋以及正、反引物各0．2μmol．L-1;扩增反应程序为,94℃预变性4min;94℃变性30s,退火30s,72℃延伸45s,35个循环;最后72％延伸10min,4℃保存。该反应条件的建立为开展云南松种质资源SSR分子标记研究提供了参考依据。     

香榧RAPD分析实验条件的优化

试验通过系统的比较研究 ,建立了香榧 RAPD分析的优化反应体系和实验条件 ,即 2 0μl的反应体系中含有 5 0 ng DNAtemplate、1.5μl 10× Buffer、1U Tag NDA聚合酶、2 .4mmol/L Mg Cl2 、2 40μmol/L d NTPs、0 .8μmol/L Primer。适宜的扩增程序为95℃变性 3 min,1个循环 ;94℃变性 3 0 s,3 6℃退火 3 0 s,72℃延伸 60 s,3 5个循环 ;72℃延伸 5 min,反应终止。该反应体系重复性高 ,条带亮度均匀 ,弥散现象少     

万寿菊RAPD分子标记优化体系的建立

以雄性不育和可育万寿菊及其子代为材料,在PE-2400型PCR仪上进行扩增,通过3次正交试验设计,优化得到了最佳的RAPD反应体系,确定了各个因素的最佳水平。在20 μL反应体系中,最佳的浓度配比为:10×Buffer中含10．00 mmol·L-1Tris-HCl、50．00 mmol·L-KCl、0．001％gelatin、dNTP0．25 mmol· L-1、TaqDNA聚合酶1．5 U、MgCl2 1．25 mmol·L-1、DNA20-60 ng、引物0．60 pmol·μL-1,预变性时间5 min, 退火温度37℃较好,1 min的延伸时间也满足了2 kb以下的DNA片段合成,循环35次能得到较好的 RAPD图谱。     

川山茶ISSR-PCR及SSR-PCR优化体系建立及比较

以川山茶品种"茶睡莲"为试验材料,以改良CTAB法提取高质量DNA,采用正交设计L16(45),探讨了Mg~(2+)、dNTPs、引物、TaqDNA聚合酶和模板DNA浓度对川山茶ISSR-PCR和SSR-PCR反应体系的影响。建立了相关优化体系:20μL的ISSR-PCR扩增体系中含20 ng模板DNA,2μL10×Buffer,2 mmol/L Mg~(2+),0.15 mmol/L dNTPs,0.6μmol/L引物和1 U TaqDNA聚合酶,扩增退火温度为55℃,35个循环;20μL的SSR-PCR扩增体系中含50 ng模板DNA,2.5 mmol/L Mg~(2+),0.05 mmol/L dNTPs,0.2μmol/L引物和0.5 U TaqDNA聚合酶,最佳退火温度为52℃,最佳循环数为38。应用该优化体系,分别用27个川山茶品种DNA进行了ISSR-PCR扩增和SSR-PCR扩增,结果显示,建立的优化体系具有较高稳定性。     

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.