低温驯化的黑荆树悬浮培养细胞中可溶性蛋白质含量变化*

低温驯化能够诱导黑荆树悬浮培养细胞增强抗冻性，ＬＴ５０从－４．３℃下降到－８．２℃。低温驯化诱可溶性蛋白质含量增加，其增加的时间进程与细胞抗冻性发育呈平行关系。环已亚胺抑制可溶性蛋白质含量增加，同时也抑制细胞抗冻性发育。在低温驯化期不同时间加入环已亚胺抑制抗冻性发育，表明低温驯化１０ｄ后抗浆性发育接近完成。糖对增加驯化细胞中可溶性蛋白质有促进作用，加快增加含量的时间进程，但对最终提高蛋白质含量水平     

柠檬的茎尖培养和植株再生

试验以柠檬的嫩茎尖作外植体，通过组培育苗，培养出完整的柠檬瓶苗并移栽成活。最佳培养基分别为：改良ＭＳ＋６－ＢＡａ＋ＩＢＡｃ诱导茎尖；改良ＭＳ＋６－ＢＡｃ＋ＩＢＡａ培养不定芽增殖；改良ＭＳ＋ＩＢＡｃ＋ＡＢＴａ诱导生根。初次培养采用全暗条件；诱导、增殖阶段适宜温度２５±５℃；生根阶段适宜温度２０±５℃；培养基ｐＨ值均约５．８。结果表明：一个茎尖年繁殖系数为３１２个，移栽成活率达９０％以上。     

甜杨抗冻性低温诱导过程中G6PDHase ,ATPase及蛋白质的变化(英文)

首次研究了低温锻炼对甜杨 (Populussuaveotlens)幼苗抗冻性的效应 ,并对低温锻炼中的G6PDHase ,ATPase及蛋白质的动态变化过程进行了测定 .另外 ,在低温锻炼前用蛋白质合成抑制剂环己亚胺对甜杨幼苗进行预处理 .试验结果表明 ,适当的低温锻炼可明显提高甜杨幼苗的抗冻性 ,但整个低温锻炼过程必须分两个阶段进行 ,第一阶段在 - 10℃的温度下锻炼 6天 ,虽对甜杨幼苗抗冻性的提高效应不明显 ,但它是不可缺少的 ,它可为第二阶段的 - 2 0℃锻炼的进行及抗冻性的完全发育提供基础 .伴随着幼苗枝条中蛋白质含量及G6PDHase和ATPase活性提高的同时 ,也明显提高了幼苗的抗冻性 ;脱锻炼 2天后 ,幼苗抗冻性下降到未锻炼水平 ,而枝条中蛋白质含量及G6PDHase和AT Pase活性虽有下降但略高于未锻炼 .蛋白质合成抑制剂环己亚胺预处理则明显降低了幼苗抗冻性和蛋白质含量 .进一步分析发现 ,低温锻炼中的G6PDHase和ATPase活性及蛋白质含量的变化与幼苗抗冻性的提高密切相关     

黑荆树离体微型繁殖的研究

运用统计分析法，对黑荆树微型繁殖各个培养程序的培养基进行筛选，从而确定适合离体快速繁殖的最优培养基组分。试验结果表明，最适合不定芽培养的培养基配方为ＭＳ＋ＢＡＰ２．０ｍｇ／Ｌ＋ＮＡＡ０～０．１ｍｇ／Ｌ＋酪蛋白水解物２００ｍｇ／Ｌ＋蔗糖３％；诱导枝芽生根的培养基为ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ＋蔗糖２％。试验还证实固体培养基诱导生根的效果比液体培养基好。     

EstablishmentofEmbryogenicCellSuspensionCulturesandDevelopmentofSomaticEmbryoonCameliasinensisvar．as

云南大叶茶成熟种子子叶诱导产生愈伤组织，在改良ＭＳ并附加０．０５ｍｇｌ－１２，４－Ｄ和０．５ｍｇｌ－１６－ＢＡ的琼脂培养基上经多次继代培养后，形成了五种类型的愈伤组织：黄色松散颗粒状（ＹＦ）、黄色半透明（ＹＳ）、绿色半透明（ＧＳ）、绿色坚硬（ＧＨ）、白色坚硬（ＷＨ）．愈伤组织的分散程度及液体培养基的组成成分影响细胞悬浮培养物的建立：①黄色松散颗粒状愈伤组织最适合建立细胞悬浮系统；②在改良的ＭＳ液体培养基中添加较高的维生素（１８．０３ｍｇｌ－１）和较高的生长素／细胞分裂素的比例（２，４－Ｄ／６－ＢＡ＝０．１／０．５）及２０ｍｌｌ－１的椰子乳，细胞生长和细胞分散程度良好．将ＹＦ接种到这种改良的ＭＳ的液体培养基中，在室温２５±２℃，每天１６小时散射光照射，１２０ｒｐｍ的旋转振荡器上悬浮培养，三周后建立了云南大叶茶的胚性悬浮系统：系统中单细胞占５．３６％，２～５个细胞的小细胞团占２３．８１％，６～２０个细胞的细胞团占７０．８３％；有丝分裂指数为３．２５％，活细胞率为７０％～８０％；悬浮培养物中细胞生长周期为１０天左右．     

黑荆树茎尖培养技术的研究

以黑荆树无菌种子苗的茎类为材料，研究了用不同的细胞分裂素，生长的浓度及其配比，培养基成分的浓度，对茎尖诱导分化芽，芽的伸长及生根的影响，研究结果；培养基为ＭＳ＋６－ＢＡ６．０ｍｇ／Ｌ＋ＬＢＡ０．０１ｍｇ／Ｌ＋ＧＡ３０．１ｍｇ／Ｌ有利于促进茎尖丛生茎的形成和伸长，１／２ＭＳ＋ＮＡＡ０．６ｍｇ／Ｌ有利于诱导芽生根，试管苗移栽成活率达９０％，并在温室里生长正常。     

黑荆树悬浮单细胞低温驯化*

由黑荆树幼茎诱导愈伤组织,由愈伤组织制备悬浮单细胞。悬浮细胞可以作为最小的驯化单位。在2℃、8h短光照条件下14d,悬浮细胞可耐受到-7.5℃(LD_(50)),而不经驯化的仅耐受到-2.5℃。悬浮细胞抗寒性是用细胞质壁分离法测定的。单一的低温或短光照驯化不能使单细胞提高抗寒力,必须低温和短光照同时存在才能使其驯化,提高抗寒力。     

凹叶厚朴组织培养的研究

采用单因子比较、正交设计、均匀设计法，分别研究了影响凹叶厚朴Ｍａｇｎｏｌｉａｂｉｌｏｂａ愈伤组织诱导和生长的各种因素。研究结果表明：愈伤组织诱导的最适培养基为Ｂ５＋２，４－Ｄ２ｍｇ／Ｌ＋６－ＢＡ１ｍｇ／Ｌ，生长的最适培养基为Ｂ５＋２．４－Ｄ１ｍｇ／Ｌ＋６－ＢＡ１．５ｍｇ／Ｌ。在培养基中添加１０％豆芽汁能够促进愈伤组织迅速生长。黑暗培养对愈伤组织的生长极为有利     

蓝桉组织培养的研究

用蓝桉（Ｅｕｃａｌｙｐｔｕｓｇｌｏｂｕｌｕｓ）离体芽器官诱导培养，分化形成丛生芽，年繁殖系数３￣（１２）。０．１～０．５ｍｇ／Ｌ的６－ＢＡ或０．５～０．８ｍｇ／Ｌ的ＫＴ诱导外植体（带节茎段）腋芽萌动的效果最佳，诱导率分别达８０．３％和８１．５％。１．５～２０ｍｇ／Ｌ的６～ＢＡ或２０～２．５ｍｇ／Ｌ的ＫＴ分别与０．５～１．０ｍｇ／Ｌ的ＮＡＡ组合，对于促进腋芽分化形成丛生芽及继代培养中芽的增殖具有最佳效果。培养基中的无机盐浓度、蔗糖含量对蓝桉试管苗的生根具有显著影响；ＩＢＡ促进蓝桉试管苗的生根。至目前为止，在１／２ＭＳ无机盐培养基＋ＩＢＡ１．２～１．４ｍｇ／Ｌ＋Ｓ５ｇ／Ｌ中诱导生根，生根率最高可达２６．４％。     

蓝桉组织培养的研究

用蓝桉（Ｅｕｃａｌｙｐｔｕｓ ｇｌｏｂｕｈｕｓ）离体芽器官诱导培养，分化形成丛生芽、年繁殖系数３＾１２。０．１－０．５ｍｇ／Ｌ的６－ＢＡ或０．５－０．８ｍｇ／Ｌ的ＫＴ诱导外植体（带节茎段）腋芽萌动的效果最佳，诱导率分别达８０．３和８１．５％。１．５－２．０ｍｇ／Ｌ的６－ＢＡ或２．０－２．５ｍｇ／Ｌ的ＫＴ分别与０．５－１．０ｍｇ／Ｌ的ＮＡＡ组合于促进腋芽分化形成丛生芽及继代培养中芽的增殖具有最佳效果     

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.