月季快速繁殖技术研究

研究不同植物生长调节剂及质量浓度对带芽茎段分化、继代和生根的影响.结果表明:月季芽的分化培养基为M S+BA 1.0 m g.L-1+NAA 0.1 m g.L-1,不定芽的诱导率为80%;在M S+BA 1.0 m g.L-1培养基上继代增值的效果较好;NAA的生根效果优于IBA,以1/2M S+0.5 m g.L-1NAA最佳.     

黄金宝树组培育苗技术研究

以黄金宝树基部半木质化萌芽条为外植体,MS为基本培养基,探讨6-BA、KT、NAA对黄金宝树组培育苗的影响,试验结果表明,黄金宝树组培育苗最佳培养基配方分别为:初代培养基MS+6-BA 0.3 mg.L-1+KT 0.5 mg.L-1+NAA 0.3mg.L-1+蔗糖30 g.L-1+卡拉胶8 g.L-1、增殖培养基MS+6-BA 0.5 mg.L-1+KT 0.3 mg.L-1+NAA 0.3mg.L-1+蔗糖30 g.L-1+卡拉胶8 g.L-1、生根培养基1/2 MS+NAA 0.5 mg.L-1+蔗糖20 g.L-1+卡拉胶8 g.L-1。初代培养诱导率达80%以上,有效芽条增殖率达3倍以上,生根率达95%以上,移栽成活率达90%以上。     

猪笼草组织培养育苗技术的研究

本试验研究了本地野生种(Nepenthes m irabilis)〔1〕带芽茎段的组织培养及植株再生,筛选出最佳培养基:(1)启动培养:M S+6BA1.0￣2.0m g·L-1+NAA0.1m g·L-1(以下单位相同)+蔗糖3%+椰汁10%;(2)增殖培养:1/2M S+6BA1+NAA0.1+蔗糖3%(3)生根培养基:1/2M S+IBA0.5+NAA1.5+蔗糖3%.     

黄花补血草组织培养试验

黄花补血草既是很好花材又可作药材。通过组织培养试验筛选出了诱导培养基M S BA0.5 NAA0.5,诱导率达92.9%;增殖培养基M S BA0.2 NAA0.2增殖系数为8.7;生根培养基采用1/2M S NAA0.1生根率较高,为65.3%。     

角茎野牡丹快速繁殖的研究

以茎段营养芽为材料,进行了角茎野牡丹的快速繁殖研究。结果表明:培养基MS+BA 0.3 mg.L-1+NAA 0.01 mg.L-1最适宜芽增殖,增殖系数达到3.1倍;在培养基1/2MS+NAA0.3 mg.L-1上无根苗培养7 d生根率85.0%,20 d生根率100%,每苗平均根数6.3条。试管苗移植成活率95.0%。     

五叶地锦离体培养及植株再生

以五叶地锦(Parthenocissus quinquefolia)子叶柄、下胚轴、叶片为外植体进行离体培养,以1/2 MS、B5和Heller为基本培养基,附加不同浓度的细胞分裂素(6-BA,KT, TDZ)及生长素(NAA)诱导下胚轴直接再生不定芽.实验结果表明,暗处理30 d,靠近下胚轴的子叶柄接种在1/2 MS 0.3 mg·L-16-BA培养基上,其不定芽分化率最高达64.67%;下胚轴接种在1/2 MS 2.0 mg·L-1KT 0.05 mg·L-1NAA和Heller 0.5 mg·L-1BA 0.1 mg·L-1NAA培养基上,其不定芽分化率接近,达到24%左右;无菌苗的叶片接种在B5 0.5 mg·L-1TDZ 0.05 mg·L-1NAA培养基上,其不定芽分化率达17.7%.芽增殖培养基为1/2 MS 0.5 mg·L-16-BA 0.1 mg·L-1NAA增殖系数为3～5, 1/2 MS 0.5 mg·L-1IBA 500 mg·L-1活性炭适于再生幼苗的生根,生根苗经移栽全部成活.     

辣木组织培养与植物激素培养基筛选试验

以辣木种子为外植体组织培养并在各培养阶段添加不同浓度植物激素培养基的试验结果表明:外植体消毒以脱壳种子→84消毒液预处理→Hg Cl2消毒效果最佳,污染率10%;最好的发芽诱导培养基为Mc+6-BA 0.4 mg·L-1,发芽率达82%;继代增殖培养基为Mc+6-BA 0.5 mg·L-1+KT 0.1 mg·L-1,增殖倍数达5.8倍;生根培养基为1/2Mc+IBA 0.5 mg·L-1+NAA 0.2 mg·L-1+AC 1.0 g·L-1,生根率达80%。炼苗20 d移栽于河沙∶珍珠岩∶刨花(1∶1∶1)混合基质的成活率最高。     

盐桦芽器官离体培养与快繁技术的研究

研究了以盐桦的带芽茎段为外植体诱导丛生芽及植株再生的过程,并筛选出其最佳分化增殖培养基为MS 6-BA0.5 mg.L-1 NAA0.02 mg.L-1 蔗糖3.0% 琼脂0.6%。经过4~6周的培养,其增殖系数为5.8;最佳生根培养基为1/2MS IBA0.3 mg.L-1 蔗糖0.15% 琼脂0.6%,生根率为100%,平均根数5.7条。     

心叶球兰组织培养与快速繁殖试验

以心叶球兰叶片为外植体,愈伤组织诱导和继代增殖培养基MS+6-BA2.0mg.L-1+NAA0.5mg.L-1+2,4-D1.0mg.L-1+GA1.0mg.L-1+白糖3%,诱导的愈伤组织多,生长旺盛,增殖倍数为2～3倍;丛芽诱导培养基MS+KT0.5mg.L-1+NAA0.5mg.L-1+GA1.0mg.L-1+白糖3%,芽的诱导率为79.3%;在丛芽增殖及复壮培养基1/2MS+IBA1.0mg.L-1+白糖2%上,有20%～30%玻璃化丛芽转为绿色苗,玻璃化单芽经复壮培养长成绿色苗;诱导生根培养基为1/2MS+IBA0.5mg.L-1+白糖2%,玻璃化生根率为56.4%,淡绿色苗生根率达91.1%。瓶苗移栽基质泥炭土∶珍珠岩∶甘蔗渣(1∶1∶1)的成活率最高,达91.4%。     

木棉离体再生体系的建立

为给木棉的快速繁殖和转基因研究奠定基础,以木棉下胚轴为外植体,探讨基本培养基种类、植物生长调节剂组合和AgNO3等因素对木棉不定芽诱导和植株再生的影响,建立了下胚轴高效再生体系。结果表明:MS+6-BA 1.5 mg.L-1+NAA 0.1 mg.L-1+KT 0.5 mg.L-1+AgNO31.0 mg.L-1+蔗糖30 g.L-1培养基最适合不定芽的分化和增殖,不定芽分化率达72%,平均每外植体分化不定芽数达3.85个。较适生根培养基为MS+NAA0.5 mg.L-1,生根率达到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.