高山杜鹃叶片再生植株的研究

研究高山杜鹃叶片再生植株无菌培养物建立、初代培养、继代培养和生根培养4个技术环节,最终建立高山杜鹃组培快速繁殖技术体系。结果表明:适宜的叶片诱导不定芽再生的培养基为WPM+TDZ0.2mg/L+NAA0.4mg/L;继代增殖培养基为WPM+KT2mg/L+NAA0.2mg/L;生根培养基为1/2MS+IBA5g/L+糖20g/L+活性碳0.5%。     

灯台树组培快繁技术研究

以灯台树带顶芽的茎段为外植体,进行了组培快繁研究。结果表明,启动培养基采用WPM BA0.5 mg/L IBA 0.2 mg/L GA31 mg/L为宜;继代增殖培养基采用M BA 1 mg/L IBA 0.2 mg/L GA32 mg/L为宜,增殖系数达4.4;生根培养则以1/2M IBA 3 mg/L配合10 d暗培养效果最好,生根率达60.0%。     

钙果6号组织培养技术研究

以钙果6号幼嫩的茎尖和茎段为外植体,对初代培养、继代培养和生根培养阶段的培养基进行筛选的结果表明,适合钙果的初代培养基配方为BA1.0mg/L+NAA0.05mg/L、继代培养基为MS+BA0.5mg/L+NAA0.05mg/L、生根培养基为1/2MS+IBA0.05mg/L。     

橡皮树的离体快繁技术研究

用MS为基本培养基,以6-BA、NAA、IBA、LH不同含量配制成培养基,在温度、光照时间和强度相同的情况下试验。其结果表明,诱导阶段可选MS+6BA0.2mg/L+NAA0.1mg/L;继代培养基可选择1/2MS+IBA0.2mg/L+NAA0.2mg/L+LH1.0mg/L;生根培养可选1/2MS+IBA0.2mg/L+NAA0.2mg/L。     

野百合组织培养的研究

以野百合鳞茎、叶片为外植体通过继代培养和生根培养,诱导不定芽的发生,进而获到再生植株。试验结果表明:用MS培养基培养野百合鳞茎、叶片组织,均能够诱导不定芽产生;在培养基中附加BA2.5mg/L和NAA0.2mg/L有利于鳞茎不定芽的诱导且芽苗长势好,而叶片则在培养基中附加BA1.5mg/L、NAA0.2mg/L的培养效果最佳;从不定芽诱导出根以1/2MS效果最好。     

华富苹果离体叶片再生的主要影响因素研究

以花药培养选育的富士品种"华富"组培苗的叶片为试材,研究了离体叶片诱导再生不定芽过程中不同激素种类与组合、暗处理时间等因素对不定芽再生率的影响。结果表明:试管苗继代培养3～4代,取顶部嫩叶3～4片,剪除叶片边缘,叶片以近轴面接种到最佳诱导再生培养基MS+TDZ 2.0mg/L+IAA 0.75mg/L+蔗糖30g/L,pH值5.8,黑暗培养10～15d后,转入光照培养条件下,再生率达83.3%～86.7%。再生不定芽分化15～20d后转接到增殖培养基MS+BA 0.5mg/L+IBA 0.1mg/L上,当不定芽长度约2cm时再转接到生根培养基1/2MS+IAA 1.0mg/L+蔗糖2%,15d后,生根率可达95.0%以上。     

葡萄不定芽离体诱导再生植株的研究

进行了紫苑、魏可和砧木 99R几个葡萄品种不定芽离体诱导再生植株的研究。实验通过对其叶片、叶柄、茎段外植体的诱导再分化 ,以器官发生途径实现植株再生。结果表明 :不同品种间存在差异 :(1)紫苑不定芽诱导再生效果最好 ,其中用IBA与TDZ组合诱导最好 ,叶柄在MS +IBA0 .2 0mg/L +TDZ0 .75mg/L培养基中再生率高达 4 2 .9% ;用IBA与BA组合效果也较好 ,叶柄和茎段在MS +IBA0 .0 5mg/L +BA2 .0mg/L中再生率达 30 .8%。 (2 )魏可叶柄不定芽诱导再生在MS +IBA0 .2 0mg/L +BA2 .0mg/L培养基再生率 2 0 .0 %。 (3)砧木品种 99R不定芽诱导再生率较低 ,叶片在MS +IBA0 .0 1mg/L +BA1.5mg/L培养基中再生率 2 0 .8%。(4)栽培品种比砧木易于诱导再生不定芽     

重瓣大岩桐茎尖培养与快速繁殖

以重瓣大岩桐茎尖为外殖体,进行组织培养,结果表明,茎尖可诱导形成愈伤组织及再生小植株。经试验筛选出各培养阶段最适宜的培养基为;①愈伤组织诱导培养基:MS BA1.5mg/L NAA0.2mg/L;②分化继代培养基:MS BA1.0mg/L NAA0.1mg/L;③生根培养基:l/2MS IBA0.2mg/L。     

洋丁香组织培养的研究

以植物园洋丁香茎段为试验材料,利用组织培养技术,筛选出诱导分化、继代增殖和生根的最佳培养基。结果表明:芽继代增殖培养基为:1/3MS+2,4D0.05(mg/L)+IBA2.0(mg/L)+NAA0.2(mg/L),最佳壮苗培养基为1/3MS+6-BA0.2(mg/L)+IBA1.0(mg/L)。最适合的生根培养基为MS+NAA0.2(mg/L)+IBA2.0(mg/L)+GA0.5(mg/L)。     

双色茉莉茎段离体培养再生植株的研究

以双色茉莉茎段为外植体,探讨外植体取材季节和部位、基本培养基种类、植物生长调节剂组合、活性炭等对茎段器官发生和植株再生的影响.结果表明:在4月和10月取材最好,其诱导率分别达到了92.780/和84%,污染率最低;1/2MS 0.01 mg/L NAA 3.0 mg/L BA 2.0 mg/L KT培养基最适合不定芽的诱导分化,不定芽分化率达到了88.34%;在继代增殖培养中,继代次数最好在6代以内,否则增殖率下降,MS 0.5mg/L IBA 3.0mg/LBA 0.2%活性炭培养基最适合不定芽的增殖(5.92)和大于2cm芽的分化(47.16%).不定芽可在1/2MS培养基中有效伸长,适宜的生根培养基为1/2MS 1.0 mg/L IBA 0.2 mg/L BA,生根率达到100%.     

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.