杂交鹅掌楸离体培养中器官发生的研究

以杂交鹅掌楸的叶片、叶柄、无菌苗的茎段及其芽基部切段为外植体,进行愈伤组织途径的器官发生及不定芽途径的直接器官发生培养。结果表明,多种外植体在诱导培养基上均能脱分化产生愈伤组织,其中无菌苗芽基部具有最高的愈伤组织诱导率。愈伤组织在MS 6-BA 2.0 mg.L-1 NAA 0.5 mg.L-1和MS 6-BA 4.0 mg.L-1 NAA 0.5 mg.L-1的分化培养基上能分化出不定芽。部分外植体在MS 6-BA 4.0 mg.L-1 NAA 0.5 mg.L-1的分化培养基上直接分化产生不定芽。器官发生途径再生体系的建立为抗逆基因工程等工作奠定了基础。     

沟叶结缕草的组织培养和无性系的建立

通过研究不同基本培养基及植物生长调节组合对沟叶结缕草丛生芽诱导、增殖和愈伤组织诱导、分化的影响,建立起沟叶结缕草试管无性系。以地下匍匐根状茎的顶芽为外植株,在MS 6-BA 2 mg.L-1 NAA 0.1 mg.L-1培养基上诱导丛生芽形成,以MS KT 3 mg.L-1 NAA 0.1 mg.L-1作为继代增殖培养基,建立起丛生芽苗→不定芽发生→丛生芽苗速生试管无性系;以丛生芽苗基部为外植体,以MS 2.4-D 4 mg.L-1作为愈伤组织诱导培养基,以MS基本培养基作为愈伤组织分化培养基,建立起丛生苗→愈伤组织→愈伤组织分化→丛生苗试管无性系。试管无性系室外移栽成活率达95%以上。沟叶结缕草试管无性系的建立为细胞工程育种和基因转化的研究奠定了基础。     

香蕉薄切片愈伤组织再生体系的建立研究

以巴西香蕉品种的薄切片为外植体高频地诱导出愈伤组织,并诱导出了不定芽,获得了再生植株。在实验过程中,利用正交实验中筛选出愈伤组织诱导的最佳培养基为MS+2,4-D 4.0 mg.L-1+KT 1.0 mg.L-1+NAA 1.0 mg.L-1+活性炭200 mg.L-1,诱导率可达100%,愈伤组织增殖的最佳培养基是MS+2,4-D 2.0 mg.L-1+6-BA 0.5 mg.L-1+NAA 0.5 mg.L-1+活性炭100 mg.L-1,继代3-4次的愈伤组织在6-BA浓度为5.0 mg.L-1的分化培养基上能分化出不定芽,继代10次之后愈伤组织在继代培养基上开始出现褐化现象,愈伤组织增殖明显受到抑制,褐化的愈伤组织逐渐死亡。     

孝顺竹愈伤组织诱导及植株再生

利用孝顺竹小穗和种胚为外植体,诱导出胚性愈伤组织并成功实现植株再生.对影响愈伤组织诱导和分化的基本培养基、激素种类及质量浓度等进行筛选,结果表明:愈伤组织诱导以NB,N6基本培养基附加4 mg·L-1 2,4-D较好;外植体在NB+500 mg·L-1脯氨酸+500 mg·L-1谷氨酰胺+300 mg·L-1水解酪蛋白+30 g·L-1蔗塘+8 g·L-1卡拉胶(Carrageenan)+4 mg·L-1 2,4-D的诱导培养基上经20 d培养,小穗愈伤组织诱导率达87.30%,种胚愈伤组织诱导率为76.27%.愈伤组织预分化及分化的基本培养基以MS较适宜,经MS+30 g·L-1蔗糖+10 g·L-1卡拉胶+4 mg·L-1 KT培养基预分化7 d后,转入无激素的MS培养基上分化14 d,小穗愈伤组织仅个别长出绿色芽头;但种胚愈伤组织芽分化率可达80.0%.分化芽中有8%左右的白化苗,并伴有花叶苗出现.优化后的种胚愈伤组织预分化最佳培养基是MS+3 mg·L-1 6-BA+3 mg·L-1 KT.分化芽苗在添加2mg·L-1 NAA的MS培养基上生根良好,移栽成活率可达70%以上.     

四倍体刺槐的组织培养快繁技术研究

以MS为基本培养基,取四倍体刺槐茎段作外植体进行组织培养研究,结果表明,MS基本培养基+6-BA 0.25mg.L-1+NAA0.05 mg.L-1可有效诱导四倍体用材型刺槐单芽茎段上的腋芽萌发并抽生成嫩梢,腋芽的萌发率为100%;转入MS基本培养基+6-BA1.0mg.L-1+NAA0.2mg.L-1或MS基本培养基+6-BA2.0mg.L-1+IBA0.5mg.L-1培养,可有效诱导丛生芽的增殖,繁殖系数可达93.8%~100%;MS基本培养基+NAA0.2mg.L-1,可诱导试管嫩梢100%生根,而且根系愈伤组织很小;并且成功地进行了试管苗的移栽,成活率达95%以上。     

短柄五加愈伤组织诱导及再生体系的建立

以短柄五加(Acanthopanax brachypus Harms)当年生嫩枝为材料,选择叶片、叶柄为外植体,使用6-BA、NAA、IBA、2,4-D等激素,配制成不同质量浓度的培养基,进行短柄五加愈伤组织诱导,同时分析愈伤组织诱导丛生芽和丛生芽增殖培养基的最佳配方,建立短柄五加植株的再生体系。结果表明,短柄五加叶片是较适宜诱导愈伤组织的外植体,愈伤组织诱导的培养基是MS+0.3mg/L 6-BA+0.5mg/L NAA,诱导率为75.0%;愈伤组织诱导不定芽形成的适宜培养基为MS+6-BA 1.0mg/L+NAA 0.1mg/L,不定芽诱导率为100%;适宜不定芽增殖的培养基为MS+6-BA3.0mg/L+NAA 0.2mg/L,增殖系数为5.80;同时活性炭能够有效防止愈伤组织诱导过程中的褐化问题。     

野葛愈伤组织诱导与不定芽分化

采用MS为基本培养基，附加NAA、6-BA和IAA3种激素．诱导野葛不同外植体愈伤组织形成；再将愈伤组织接种在不同浓度6-BA的MS培养基上．分别在光照和黑暗条件下进行不定芽的诱导。结果表明．野葛幼叶、茎段和顶芽在适宜激素的诱导下均能形成愈伤组织，但不同激素组合其愈伤组织诱导率不同。幼叶愈伤组织诱导的最适培养基为MS NAA1．0mg／L 6-BA1．0mg/L．其诱导率为75％．茎段愈伤组织诱导的最适培养基为MS NAA1．0mg／L 6-BA3．0mg／L IAA0．2mg/L，其诱导率为70％。不同外植体形成的愈伤组织其不定芽的分化诱导率不同．茎段愈伤组织在不同浓度6-BA下均能诱导出不定芽；光照有利于芽的分化．在光培养条件下，茎段愈伤组织不定芽平均诱导率为66．7％。     

丹红杨愈伤组织诱导与器官再生的影响因子分析

采用正交设计,首次建立了丹红杨离体培养技术体系.结果表明:丹红杨叶片最佳胚性愈伤组织诱导培养基为MS+2,4-D0.20 mg/L+6-BA1.00 mg/L,诱导率为57.50%;叶柄、无芽茎段最佳胚性愈伤组织培养基诱导为MS+6-BA0.30～0.80 mg/L+ZT0.30～0.80 mg/L+NAA0.02～0.05 mg/L,诱导率为82.26%;根最佳胚性愈伤组织诱导培养基为MS+6-BA1.00 mg/L+KT0.50～1.00 mg/L+NAA0.50～1.00 mg/L.胚性愈伤组织增殖最佳培养基为MS+BR0.10 mg/L+NAA 0.10 mg/L.胚性愈伤组织分化不定芽最佳培养基为WPM+6-BA0.20 mg/L+TDZ0.001～0.003 mg/L+KT0.50 mg/L+NAA0.05～0.10 mg/L.     

麻疯树叶盘法高效再生的研究

以温室中1年生麻疯树顶端幼嫩叶片为外植体,研究了在MS基本培养基中添加不同浓度的6-苄基腺嘌呤(6-BA)和吲哚丁酸(IBA)对不定芽再生的影响,并采用60天暗培养的方法筛选出愈伤组织诱导和不定芽诱导的最佳激素组合为MS+5 mg.L-16-BA+0.5 mg.L-1IBA,该组合的不定芽诱导率高达75.8%。将该组合诱导出的愈伤组织接种至MS+1.5 mg.L-16-BA+0.05 mg.L-1IBA的固体培养基中,研究了赤霉素对不定芽再生的影响,最佳赤霉素浓度为0.05 mg.L-1,麻疯树叶盘再生率达到90.9%,平均不定芽个数达到4.6个。     

印度萝芙木组织培养技术研究

以印度萝芙木枝条顶芽为外植体进行离体培养,外植体最佳灭菌方法为0.08%HgCl2处理时间20min;诱导愈伤组织培养基为MS+L-半胱氨酸0.02mg·L-1+6-BA2.0mg.L-1+NAA0.2mg·L-1,诱导率可达100%;诱导不定芽培养基为MS+L-半胱氨酸0.01mg·L-1+6-BA1.0mg·L-1+NAA0.1mg·L-1;生根培养基为1/2MS+NAA1.0mg·L-1,生根率可达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.