钟花樱组织培养繁殖研究

以钟花樱(Cerasus campanulata)的嫩枝作外植体进行组织培养技术研究。结果表明：适合不定芽诱导的培养基为 MS+6-BA 1.0 mg · L-1+NAA 0.1 mg · L-1+蔗糖30 g · L-1+卡拉胶6.5 g · L-1,诱导率为44.44%,适合增殖培养的培养基为 MS+6-BA 1.0 mg · L-1+NAA 0.05 mg · L-1+GA30.5 mg · L-1+蔗糖30 g · L-1+卡拉胶6.5 g · L-1,增殖倍数为3.70,适合生根培养的培养基为1/2 MS+IBA 1.5 mg · L-1+NAA 0.1 mg · L-1+蔗糖30 g · L-1+卡拉胶6.5 g · L-1+活性碳0.5 g · L-1,生根率为82.23%。     

探讨不同浓度的外源激素对矮牵牛组织培养的影响

研究了不同浓度配比的NAA ,6-BA对矮牵牛组织培养过程中愈伤组织增殖、芽分化和生根的影响。结果表明:MS +NAA0 .2mg·L- 1 +BA1.0mg·L- 1 培养基对愈伤组织增殖效果最好;最佳的分化培养基为MS +BA1.0～1.5mg L +NAA0 .3～0 .5mg L ;而生根的培养基可选1 2MS +NAA0 .5～1.0mg L。     

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%。     

齿瓣石斛组织培养技术研究

以齿瓣石斛蒴果为外植体进行胚培养的试验表明,初始萌发培养基为1/2MS;原球茎萌发培养基为3/4MS+10%马铃薯汁+5%香蕉汁+6-BA0.2mg·L-1+NAA0.05mg·L-1+0.05%AC;继代增殖培养基为MS+10%马铃薯汁+10%香蕉汁+6-BA0.5mg.L-1+NAA0.2mg.L-1+0.1%AC;壮苗生根培养基为1/2MS+10%香蕉汁+5%马铃薯汁+6-BA0.2mg·L-1+NAA1.0mg·L-1+0.1%AC,生根诱导率达100%,成活率达90%以上。     

大岩桐组培育苗试验

以大岩桐幼嫩叶片、老叶、带腋芽的茎段为外植体,进行试管诱导,并进行继代、生根、移栽试验.结果表明:大岩桐诱导外植体以带腋芽的茎段效果最好;适宜的启动培养基、增殖培养基和生根培养基分别为MS+6-BA 1.0mg· L-1+NAA0.2mg·L-1、MS+6-BA0.5 mg·L-1 +NAA0.1 mg·L-1和1/2...     

刺山柑腋芽的组织培养快繁技术研究

以从意大利西西里岛引进的刺山柑带腋芽茎段为外植体,进行了预处理、丛芽诱导、丛芽增殖和生根、再生植株炼苗等研究,采用正交设计筛选出各阶段的适宜培养基.结果表明:在诱导阶段,较低的激素水平能促进幼芽萌发,其适宜的培养基为DKW+0.3 mg·L-16-BA+0.05 nag·L-1NAA+20 g·L-1庶糖;继代增殖阶段,丛芽增殖系数与6-BA用量成正比,但随着6-BA用量加大或长期在高浓度6-BA上培养,芽苗多且细弱,不适合做生根诱导,其适宜的培养基为DKW+0.3 mg·L-16-BA+0.025 mg·L-1NAA+30 g·L-1庶糖;生根培养阶段,其适宜的培养基为1/2MS+0.2 nag·L-1 IBA+100～200 mg·L-1 VB1+20 g·L-1庶糖,生根率87%.生根组培苗移植至草炭灰:珍珠岩(3:1)基质中成活率为92.31%.     

银莓离体快繁技术研究

以银莓当年生枝的顶芽和腋芽为外植体,以MS为基本培养基,添加不同配比的植物生长调节剂进行离体培养.结果表明:芽诱导最适宜的培养基为MS+6-BA3.0 mg·L-1+NAA3.0 mg·L-1+蔗糖30 g·L-1+琼脂4.5 g·L-1,增殖培养基为MS+6-BA1.0 mg·L-1+NAA1.0 mg·L-1+蔗糖...     

不同浓度的外源激素对矮牵牛组织培养的影响

研究了不同浓度配比的NAA ,6 -BA对矮牵牛组织培养过程中愈伤组织增殖 ,芽分化和生根的影响。结果表明 :MS+NAA0 .2mg·L- 1+BA1.0mg·L- 1培养基对愈伤组织增殖效果最好 ;最佳的分化培养基为MS+BA1.0 - 1.5 +NAA0 .3- 0 .5 ;而生根的培养基可选 1/2MS +NAA0 .5 - 1.0。     

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.     

两种优良巴西杂交桉树的组织培养和快速繁殖

本研究以巴西尾巨桉和巨赤桉两种优良杂交桉树的带芽茎段为外植体进行离体培养和快速繁殖研究.结果表明:尾巨桉和巨赤桉再生芽诱导的最佳培养基为改良MS+6-BA 0.5 mg·L-1+NAA 0.2 mg·L-1,继代增殖的最适培养基为改良MS+6-BA 0.5 mg·L-1+NAA 0.15 mg·L-1.芽诱导和继代增殖中6-BA的浓度对两种杂交桉树有显著影响.生根培养中,尾巨桉和巨赤桉生根情况差异显著,尾巨桉茎芽最适生根培养基为1/2MS+NAA0.2 mg·L-1+IBA 1.0 mg·L-1,巨赤桉茎芽最适生根培养基为1/2MS+NAA 0.15 mg·L-1+IBA 1.0 mg·L-1.两种杂交桉树组织培养体系的建立,为桉树良种选育和遗传转化体系的研究提供技术参考.     

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.