植物生长调节剂对黑果枸杞愈伤组织诱导、增殖及分化的影响

为建立黑果枸杞高频再生体系及进行细胞突变体筛选、遗传转化奠定基础,以黑果枸杞叶片、茎段和腋芽为外植体,以MS为基本培养基,附加不同浓度的植物生长调节剂进行愈伤组织的诱导、增殖及不定芽分化研究。结果表明:诱导愈伤组织的最佳培养基为MS+2,4-D 2.0mg/L+6-BA 0.5mg/L;在愈伤组织的继代培养过程中,高浓度的2,4-D有利于愈伤组织的诱导,但对愈伤组织的生长有一定的抑制作用,最佳培养基为MS+2,4-D 1.0mg/L+6-BA 0.5mg/L;在愈伤组织的再分化过程中,6-BA对再生芽的分化效果最好,出芽率高,且多诱导出丛芽,最佳培养基为MS+6-BA 2.0mg/L+NAA 0.10mg/L。试验表明:黑果枸杞叶片、茎段和腋芽均可诱导愈伤组织,茎段诱导率最高;筛选出了茎段愈伤组织诱导、增殖及再生芽分化的适宜培养基,为其细胞工程育种及规模化生产提供支撑。     

红松成熟合子胚愈伤组织诱导的适宜培养条件

为了探索以红松成熟合子胚为外植体诱导愈伤组织的适宜培养条件,以GD、DCR、LM、MS等为基本培养基,以2,4-D和6-BA组成不同浓度激素组合,进行愈伤组织诱导试验。结果表明,1供试培养基均可诱导红松成熟合子胚产生愈伤组织,但DCR培养基上诱导的愈伤组织出现最早,出愈率显著高于其他培养基,达93.3%;2在DCR培养基中添加2,4-D与6-BA的各种组合均获得了较好的愈伤组织发生,但以2,4-D 2 mg/L+6-BA 0.5 mg/L和2,4-D6 mg/L+6-BA 1 mg/L的出愈率最高,达96.7%。综上所述,红松成熟合子胚外植体诱导愈伤组织时,适宜基本培养基为DCR,适宜激素组合为2,4-D 2 mg/L+6-BA 0.5 mg/L。     

朱顶红愈伤组织诱导及增殖发育体系的建立及优化

以朱顶红带有小鳞茎的试管苗作为外植体,进行愈伤组织的诱导、增殖及不定芽分化研究,结果表明:诱导愈伤组织形成的最佳培养基为MS+2,4-D 2.0mg/L+6-BA1.0mg/L+KT2.0mg/L。愈伤组织增殖需要的最佳2,4-D 2.0mg/L浓度为1.0mg/L,促进不定芽分化及植株再生的6-BA浓度为0.5mg/L。     

无患子愈伤组织诱导与分化培养技术研究

为解决无患子组织培养中的难题,对愈伤组织诱导最佳外植体与基本培养基类型先进行筛选,再通过正交试验设计,筛选愈伤组织诱导植物生长调节剂、生长及分化培养最佳抗褐化剂和植物生长调节剂种类与浓度水平。结果显示：(1)1 a生嫩茎段是无患子愈伤组织诱导最佳外植体;(2)培养基中添加20.0 mg/L抗坏血酸和10.0 mg/L半胱氨酸能有效抑制愈伤组织褐化现象的发生;(3)以改良MS作为基本培养基,外加6-苄基腺嘌呤(6-BA)0.6 mg/L+糠基腺嘌呤(KT)0.15 mg/L+2,4-二氯苯氧乙酸(2,4-D)3.0 mg/L植物生长调节剂浓度组合,愈伤组织诱导率最高,结构致密;(4)愈伤组织团在改良MS外加6-BA 3.0 mg/L+萘乙酸(NAA)0.4 mg/L+吲哚丁酸(IBA)0.25 mg/L植物生长调节剂浓度组合下,不定芽诱导率最高,芽苗健壮。     

杉木愈伤组织诱导及植株再生

以杉木成熟合子胚为起始外植体,研究了基本培养基、植物激素、凝固剂种类、有机附加物等因素对杉木愈伤组织的诱导、愈伤组织的继代培养及不定芽分化的影响。结果表明:1/2MS+2,4D2mg/L+6-BA1mg/L+KT1mg/L+糖30g/L是成熟合子胚诱导愈伤组织的最佳培养基;1/2MS+2,4-D1mg/L+6-BA0.5mg/L+KT0.5mg/L+糖30g/L适于杉木愈伤组织继代增殖;改良MS+6-BA0.5mg/L+KT1.5mg/L+蔗糖30g/L是诱导不定芽发生的最佳培养基。     

构树胚性愈伤组织及体胚诱导研究

以野生构树组织培养无菌苗茎段为外植体,探讨不同种类、质量浓度的植物生长调节剂对胚性愈伤组织诱导及体胚发生的影响,初步建立愈伤组织诱导及体胚发生技术途径。结果表明,TDZ是影响构树茎段胚性愈伤组织诱导的主要因素,NAA和2,4-D是次要因素,构树胚性愈伤组织最佳培养基为MS+0. 05 mg/LTDZ+1. 0 mg/L NAA+0. 1 mg/L 2,4-D。最佳体胚诱导培养基为MS+0. 1 mg/L NAA+1. 0 mg/L 6-BA,体胚诱导率达到41. 33%。     

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。     

北乌头组培快繁技术体系初步研究

本文对北乌头组培快繁技术体系进行了初步研究,同时比较了不同外源激素组合对北乌头外植体诱导的影响,其结果表明:北乌头愈伤组织诱导最佳外植体为叶片,丛生芽诱导最佳外植体为带芽茎段及茎尖,愈伤组织诱导最佳培养基为MS+1.0mg/L6-BA+1.0mg/L2,4-D,丛生芽诱导最适合培养基为MS+1.0mg/L2,4-D+0.2mg/LNAA,继代培养以WPM+1.0mg/L6-BA+0.5mg/LIBA效果最为显著,增殖率在4倍以上;北乌头生根最佳培养基为1/2MS+0.1mg/LNAA,生根率可到90%。     

陈山红心杉胚性愈伤组织的培养

以未成熟陈山红心杉胚胎为外植体,MS为基本培养基,通过添加不同浓度的6-BA和2,4-D,研究胚性愈伤组织的培养条件.结果表明:2,4-D是胚性愈伤细胞分化和生长的关键因子,最佳培养条件是:MS+6-BA 0.5mg/L+2,4-D 1.0mg/L,继代周期40天左右.     

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.     

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.