红松SSR-PCR反应体系的建立与优化

为了建立红松SSR-PCR最佳反应体系,以CTAB法提取的红松针叶DNA为模板,应用单因子试验及L16(45)正交试验系统分析了DNA模板浓度、Mg2+浓度、dNTPs浓度、引物浓度、Taq酶浓度等对SSR-PCR扩增结果的影响,并对延伸时间、热循环参数进行了探讨,建立了稳定的、可重复的红松SSR-PCR最佳反应体系及PCR扩增参数。结果表明,PCR的最佳反应体系为:10μL体系中,1×PCRbuffer1μL、DNA模板50～120ng,Mg2+3mmol/L,dNTP0.4mmol/L,引物0.5μmol/L,Taq酶0.75U。利用该体系筛选出扩增条带清晰、多态性丰富的SSR引物13对。在此反应体系下,所扩增谱带清晰、稳定、多态性高。     

桉树SRAP标记体系的优化及遗传多样性分析

为确立按树SRAP-PCR反应体系,并对桉树品种进行遗传多样性分析,以巨尾桉GL -9号嫩叶提取的DNA为模板,进行Mg2+、dNTP、引物和Taq DNA聚合酶4个因素3个水平L9(34)正交试验,并比较了不同浓度模板DNA对PCR扩增效果的影响.结果显示:桉树的SRAP-PCR最佳反应体系为Mg2+2.5 mmol/L、dNTP 0.20mmol/L、引物0.4μ mol/L、Taq DNA聚合酶1.5U,DNA模板最佳浓度为10ng.利用最佳反应体系对桉树品种进行引物组合多态性筛选,从40个引物组合中筛选出多态性引物组合17个.挑选12个多态较高的引物组合对11个按树品种进行遗传多样性分析,通过PCR扩增,得到109个谱带.其中多态性条带95条,平均每个引物组合产生7.92个多态性条带,显示了相对较高的多态性.表明SRAP标记可应用于按树分子生物学研究.     

刨花润楠SRAP-PCR体系建立与优化

以刨花润楠(Machilus pauhoi)1.5 a生小苗幼嫩叶片为试材,对影响刨花润楠SRAP-PCR扩增的模板DNA量、引物、dNTP和Mg2+体积摩尔浓度、Taq DNA聚合酶、退火温度6个主要因素进行优化.结果表明,SRAP-PCR的最佳反应体系为:25μL的SRAP-PCR反应体系中,2.5μL 10×PCR buffer、模板DNA量60 ng、Mg2+2.0 mmol/L、dNTP 0.225 mmol/L、引物0.3μmol/L和Taq DNA聚合酶1.25 U.对优化的反应体系和扩增程序的验证结果表明,优化的刨花润楠SRAP-PCR反应体系和扩增程序是稳定可行的.     

山茶ISSR扩增条件的优化

以山茶基因组DNA为材料,测试山茶ISSR扩增的最适退火温度,并采用单因素试验,测试了模板DNA量,Mg2+浓度,dNTP浓度,BSA浓度,引物用量,Taq酶用量等6个因素对山茶ISSR扩增的影响。结果显示:山茶ISSR扩增的最适退火温度为56.3℃;适宜的扩增体系为:10μL PCR反应体积中,1×Taq酶配套缓冲液(10 mmol.L-1Tris.HCl pH 9.0,50mmol.L-1KCl,0.1%Triton X-100),2 mmol.L-1MgCl2,0.6 mmol.L-14×dNTP,2 mg.ml-1BSA,16 ng模板DNA,10 pmol引物,0.5 U Taq酶。     

萱草属植物ISSR-PCR反应体系的优化

以萱草属的3种植物为材料,对影响ISSR-PCR扩增效果的因素Taq酶用量、Mg2 浓度、dNTP用量、引物用量、模板DNA浓度以及退火温度等指标进行单因子筛选和优化,建立了适合萱草属植物ISSR-PCR分析的最佳PCR反应体系:20μL反应体系中Taq酶0.6U、Mg2 1.8 mmol/L、1×Buffer 2 μL、dNTP0.2 mmol/L、引物0.6mmol/L、DNA模板10 ng/μL.扩增程序为94℃预变性5 min,94℃变性40 s,52℃退火45 s,72℃延伸1.50 min,共39个循环;72℃完全延伸5 min,4℃保持.该反应体系及扩增程序扩增谱带清晰,产物量多,为利用ISSR-PCR分子标记研究萱草属植物的遗传多样性提供标准反应条件.     

朱砂根ISSR反应体系的建立与优化

分析了不同DNA浓度、Mg2 、dNTP、引物用量对朱砂根ISSR-PCR扩增结果的影响,确立适合朱砂根的ISSR反应体系为:在20μl反应体系中,含1×buffer、30ng模板DNA、随机引物量0.4 μmol/L、dNTP0.15 mmol/L、Mg2 1.75 mmol/L、IUTaq DNA聚合酶.     

云南金花茶SSR-PCR反应体系的建立与优化

以云南金花茶为试验材料,利用试剂盒法、SDS法及CTAB法3种方法提取其DNA,并对3种方法的提取结果进行比较;经初筛合成云南金花茶EST-SSR引物,并对影响SSR-PCR体系的Mg~(2+)、Taq DNA聚合酶、dNTP、引物及模板DNA这5个因素进行L_(16)(45~)正交实验,以期建立较为稳定的云南金花茶SSR-PCR体系。试验结果表明:试剂盒法提取得到的云南金花茶DNA质量最好且符合SSR分子标记试验。各因素对PCR扩增效果的影响程度为:Mg2+引物 Taq DNA聚合酶 dNTP模板DNA。试验最终确定的金花茶SSR-PCR最佳反应体系(20μL)为:2.0μL Taq Buffer、1.5μL Mg2+(25 mmol/L)、0.3μL dNTP(10 mmol/L)、0.2μL Taq DNA聚合酶(5 U/μL)、前后引物各0.4μL(10μmol/L)、0.5μL模板DNA(50 ng/μL)、14.7μL ddH_2O。建立和优化云南金花茶SSR反应体系,可为云南金花茶不同种群的遗传变异研究提供基础。     

适用于厚朴的SRAP反应体系的建立与优化

利用正交试验L16(45),结合单因素试验对厚朴相关序列扩增多态性(Sequence-related amplified polymorphism,SRAP)标记反应体系的5个因素(Mg2+,dNTPs,引物,Taq酶和模板DNA)进行优化试验,结果表明:各因素水平变化对PCR反应的影响从大到小依次为:dNTPsTaq酶模板DNAMg2+引物;筛选出各反应因素的最佳水平,建立厚朴SRAP-PCR反应的最佳体系(25μL)为:Taq酶1.5 U,Mg2+1.8 mmol.L-1,模板DNA100 ng,dNTP 0.24 mmol.L-1,引物0.40μL。试验表明,该体系重复性好、稳定性强。     

漾濞泡核桃ISSR-PCR反应体系的建立和优化

以漾濞泡核桃优株为研究对象,研究其ISSR-PCR反应体系中的5个影响因子(模板DNA浓度、Taq DNA聚合酶浓度、引物浓度、dNTPs浓度、Mg2+浓度)对PCR扩增效果的影响,从而建立起漾濞泡核桃的最佳ISSR-PCR反应体系。结果表明:模板DNA最佳浓度为50 ng/(25μL),Taq聚合酶浓度为0.75U/(25μL),引物浓度为0.7mmol/L,dNTPs浓度为0.20mmol/L,Mg2+浓度为2.0mmol/L,利用该最佳体系对试验中所选取的样本进行扩增反应。建立了适宜于漾濞泡核桃的ISSR-PCR扩增的最佳体系,该体系的建立为利用ISSR分子标记技术对漾濞泡核桃进行种质资源研究奠定了基础。     

润楠ISSR-PCR优化反应体系建立及引物筛选

以润楠基因组总DNA为材料,利用单因素试验设计方法,对影响ISSR-PCR扩增的模板DNA、Mg2+、dNTPs、引物、Tag DNA聚合酶以及去离子甲酰胺等试验因子进行了优化试验,筛选出16条有效引物并确定了它们的退火温度,并检测了体系的重复性。优化后的反应体系为:20μL PCR反应体积中,10×PCR Buffer 2μL,2.0mmol/L Mg2+1.6μL,0.2 mmol/L dNTPs 2μL,0.4 mmol/L引物0.8μL,0.5U Taq DNA聚合酶0.1μL,40 ng DNA模板1.0μL,1.5%去离子甲酰胺0.3μL,ddH2O 12.2μL。扩增程序为:94℃预变性5 min,94℃变性30 s,据不同引物的退火温度复性45 s,72℃延伸90 s,反应37个循环,最后在72℃延伸7 min。润楠ISSR-PCR反应体系的建立为利用ISSR分子标记技术研究润楠的遗传多样性奠定了良好的基础。     

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.