印楝快繁技术的研究

试验以印楝实生苗的嫩枝为材料,对印楝的初代培养、丛生芽诱导和生根、再生植株炼苗等进行系统研究,通过单因素和正交试验筛选出各阶段的最适培养条件:(1)初代培养基为MS 6-BA 0.5 mg/L NAA 0.05 mg/L 蔗糖30 g/L;(2)丛生芽诱导培养基为MS改 6-BA 0.4~1.0 mg/L KT 0.5~1.5 mg/L NAA 0.05~0.2 mg/L 蔗糖30 g/L;(3)生根培养基为1/2 MS IBA 0.3 mg/L PG 3μmol/L 糖20 g/L。     

海南龙血树组织培养快速繁殖技术研究

以海南龙血树优株顶芽和茎段为外植体,通过不同细胞分裂素、生长素以及培养基不同浓度的组合对诱导芽的分化、增殖、伸长及生根的对比实验及试管苗移栽管理,筛选出MS 蔗糖30 g/L 6-BA 3．0 mg/L NAA 0．01 mg/L培养基诱导芽的形成,MS 蔗糖30 g/L 6-BA 2．0 mg/L NAA 0．01 mg/L培养基用于芽的增殖,MS 蔗糖30 g/L 6-BA 0．5 mg/L培养基用于壮芽伸长;1/2MS 蔗糖15 g/L NAA 0．2 mg/L用于诱导芽生根;选用泥炭土、椰糠和珍珠岩混合基质,于晚春和秋季移栽试管苗,成活率达90％左右,达到工厂化苗木生产的要求。     

油茶组织培养繁殖技术初步研究

以油茶（Camellia oleifera）种子胚芽和2a生扦插苗带侧芽的嫩枝作外植体进行组织培养技术研究。结果表明：适合油茶种子胚芽诱导的培养基为MS＋6-BA2．0mg／L．4-NAA0．2mg／L＋GA31．0mg／L＋蔗糖30g／L＋卡拉胶6．5g／L,适宜的增殖培养基为MS＋6-BA1．5mg／L＋NAA0．1mg／L＋GA31．0mg／L＋蔗糖30g／L＋卡拉胶6．5g／L,增殖倍数为3．50;适合油茶不定芽诱导的培养基为MS＋6-BA1．5mg／L＋IAA2．0mg／L＋GA,1．0mg／L＋蔗糖30g／L＋卡拉胶6．5g／L,适宜的增殖培养基为MS＋6-BA2．0mg／L＋IAA1．0mg／L＋GA,1．0mg／L＋蔗糖30g／L＋卡拉胶6．5g／L,增殖倍数为3．96。木质化程度已较高的油茶组培茎芽适宜的生根基质为细沙,生根率达95％。     

两种外源激素在白掌组织培养不同阶段的剂量研究

文章研究了不同浓度的细胞分裂素6-BA对白掌外植体诱导、愈伤组织增殖、不定芽增殖及生长素IBA对诱导生根的影响。结果表明：初代培养基以1／2MS CM100ml／L 蔗糖30g／L 琼脂6g／L 6-BA 1.0mg／L效果最好；在培养基MS NAA 0．1mg／L 蔗糖30g／L 琼脂6g／L中添加6-BA 1.0mg／L愈伤组织和不定芽的增殖倍数最高；在培养基1／2MS 活性炭2g／L 蔗糖30g／L 琼脂6g／L中添加2．0mg／L IBA可显著提高生根率。     

灰毡毛忍冬新品种组培高效增殖体系的建立

以灰毡毛忍冬新品种‘金翠蕾’为材料，研究了基本培养基、MS培养基大量营养元素含量、植物生长调节剂浓度、生物素及蔗糖浓度对组培丛生芽增殖的影响。结果表明，在MS、WPM、WH、B，基本培养基中，MS比较适合丛生芽的增殖和生长；MS中的硝酸钾和磷酸二氢钾的台量对丛生芽增殖影响较大，以硝酸钾为零，磷酸二氢钾、硝酸铵、氯化钙和硫酸镁分别减半为宜；蔗糖浓度对丛生芽的增殖影响不显著，但以30g／L为宜；添加生物素D以及低浓度6-BA和NAA有利于丛生芽增殖与生长；适宜的增殖培养基为改忘MS＋6-BA0．5mg／L＋NAA0．05mg／L＋生物素1．0mg/L。     

薜荔茎段的组织培养与植株再生技术

以薜荔茎段为外植体,研究了其丛生芽诱导和快繁技术.实验结果表明,B5为最适合的基本培养基,根据正交试验结果,各激素对诱导丛生芽的作用大小为:6-BA>NAA>KT>IAA,诱导丛生芽的最佳培养基为:B5 1 mg/L NAA 0.1 mg/L IAA 1mg/L KT 2 mg/L 6-BA 蔗糖20 g/L 琼脂0.75%;生根培养基以B5 3 mg/L NAA 0.1 mg/L IAA 1 mg/L KT 2 mg/L6-BA 蔗糖20 g/L 琼脂0.75%为宜.     

不同因素组织培养对山苍子茎段腋芽生长发育的影响

以山苍予带腋芽的茎段为外植体。研究了影响茎段诱导分化丛生芽、增殖与生根的主要影响因素。结果表明：山苍子通过茎段外植体直接分化丛芽进行离体培养的途径。最佳丛生芽诱导分化的培养基是1／2MS＋6-BA2.0mg／L＋NAA0.1mg／L，＋AC0.5g／L；最佳增殖培养基为WPM-6-BAl．0mg／L十IBA0．1mg／L＋Vclmg／L，以不定芽形式增殖，增殖系数为5．6，增殖周期为30d左右；生根培养基为改良1／2MS＋NAA0.3mg/L＋IBA0.2mg／L＋AC0.5g／L，生根率91％。     

欧美杨108高效组培再生系统

欧美杨108生产性状优良,是基因工程转化的理想受体,高效的组培再生系统是转化工作的基础。以欧美杨108茎段、叶柄、叶片3种外植体为起始材料,确定了植株再生过程中诱导丛生芽、芽的茎伸长和生根培养的最优培养条件,建立了稳定高效的再生培养系统。结果表明:基本培养基MS优于WPM;最适从生芽诱导培养基为MS+TDZ 0.05 mg/L+6-BA 0.05 mg/L+NAA 0.05 mg/L+蔗糖30 g/L,茎段、叶柄、叶片3种外植体丛生芽诱导率分别达100%、100%和86%。丛生芽需要进行茎伸长诱导的环节,茎伸长诱导效率最高是MS+KT 0.5 mg/L+GA3 2 mg/L+果糖30 g/L培养基,茎段和叶柄丛生芽茎伸长诱导最好,诱导培养20 d,得到平均芽长3 cm的有效芽,增殖系数大于4。抽茎芽转入生根培养前,须经MS基本培养基壮化培养。在1/2 MS+IAA0.02 mg/L+IBA 0.02 mg/L+AC3 g/L+蔗糖30 g/L培养基上,试管苗生根率可达100%,苗体健壮。欧美杨108高效组培再生系统为其遗传转化奠定了基础。     

“小仙女”观音莲工厂化组织培养技术研究

为提高"小仙女"观音莲的组培工厂化水平,以其顶芽为试材,对丛生芽诱导、丛生芽增殖及状态调整、生根等因素进行了研究。结果表明:最适宜单芽诱导丛生芽培养基为MS+6-BA2.5mg/L+NAA0.1mg/L,最适丛生芽增殖培养基为MS+6-BA1.5mg/L+NAA0.1mg/L,最适丛生芽增殖培养基为改良MS+6-BA1.5mg/L+NAA 0.1mg/L,最适生根培养基为MS+NAA0.4mg/L+IBA0.2 mg/L+活性炭0.5g/L+糖30g/L。     

华灰莉木的组织培养与快速繁殖

文章对华灰莉木组织培养快繁育苗技术进行研究。结果表明,以华灰莉木嫩茎为外植体,不定芽增殖系数高达2．095倍,持续增殖培养时,每个继代周期约有35％～40％的不定芽可分切转生根培养。适宜华灰莉木不定芽快速增殖的培养基为MS＋6-BA3．0mg／L＋NAA0．1mg／L,或MS＋6-BA3．5mg／L＋NAA0．2mg／L,蔗糖30g／L;而诱导生根的适宜培养基为1／2MS＋IBA1．0～2．0mg／L,蔗糖15g／L,生根率达94％。生根试管植株炼苗后移植存活率达90％。     

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.