枣树原生质体培养及其植株再生

以无核小枣和鸡蛋枣两个枣树品种的胚性悬浮细胞经酶解获得的原生质体为材料,采用不同种类的培养基、不同含量的ＮＡＡ 和 ＺＴ 激素组合及不同原生质体培养密度对两个枣树品种的原生质体进行培养,以获得适宜的培养基种类、较佳ＮＡＡ 和ＺＴ 的激素组合及适宜的培养密度。结果表明：用ＫＭ ８ｐ 作培养基,附加 ０．３ ｍ ｇ／Ｌ ＮＡＡ＋ ０．２ ｍ ｇ／Ｌ ＺＴ 的激素组合,以５×１０５ 个原生质体／ｍ Ｌ 的培养密度, 对其原生质体经 １０ 周液体浅层培养,可获得直径约为 １ ｍ ｍ 的微愈伤组织。将这些微愈伤组织先后转入低渗ＫＭ ８ｐ ＋ ３．０ ｍ ｇ／Ｌ ＮＡＡ＋ ０． ２ ｍ ｇ／Ｌ ＺＴ 琼脂培养基和Ｍ Ｓ［（１／２）ＮＯ－３ ］＋ ３．０ｍ ｇ／Ｌ ＮＡＡ＋ ２．０ｍ ｇ／Ｌ ＺＴ 琼脂培养基上增殖, 再转入枣树分化培养基中,可获得完整的原生质体再生植株     

小叶杨原生质体培养中的激素和氨含量变化

以小叶杨（Ｐｏｐｕｌｕｓｓｉｍｏｎｉｉｃａｒｒ．）原生质体培养的愈伤组织为供试材料，用高压波相色谱法（ＨＰＬＣ），测定它们在四种不同分化培养基上四大类内源激素（ＩＡＡ，ＧＡ３，ＣＴＫ，ＡＢＡ）的含量变化，并检定有关Ｎ的生化反应。结果表明，不同分化培养基上的愈伤组织中内源激素含量和种类差异很大。导致细胞分裂素（ＣＴＫ）含量高，种类多以及细胞分裂素与生长素的比值（ＣＴＫ／ＩＡＡ）高的处理，有利于愈伤组织分化；但若愈伤组织中含有内源脱落酸（ＡＢＡ），则抑制分化。测定结果还表明，小叶杨原生质体培养的愈伤组织分化过程中，其硝酸还原酶活力与氨基态Ｎ含量互为消长。分化频率高的愈伤组织中，硝酸还原酶活力低，而氨基态Ｎ含量高．     

小叶杨原生质体培养中的激素和氮含量变化

以小叶杨原生质体培养的愈伤组织为供试材料，用高压液相色谱法（ＨＰＬＣ），测定它们在四种不同分化培养基上四大类内源激素（ＩＡＡ，ＧＡ３，ＣＴＫ，ＡＢＡ）的含量变化，并检定有关Ｎ的生化反应，结果表明，不同分化培养基上愈伤组织中内源激素含量和种类差异很大，导致细胞分裂素（ＣＴＫ）含量高，种类多以细胞分裂素与主长素的比值（ＣＴＫ／ＬＡＡ）高的处理，有利于愈伤组织分化；但若愈伤组织中含有内源脱落酸（ＡＢＡ）     

桉树原生质体分离体系建立研究初报

以雷林一号桉及尾叶桉为对象进行了原生质体分离体系建立研究,结果表明：雷林一号桉及尾叶桉胚性愈伤诱导的最适应培养基分别为：Ｂ５＋２,４－Ｄ２．０ｍｇ／Ｌ＋ＫＴ０．８ｍｇ／Ｌ及Ｂ５＋２,４－Ｄ２．０ｍｇ／Ｌ。胚性愈伤继代培养基为：Ｂ５＋２,４－Ｄ０．５～１．０ｍｇ／Ｌ＋ＫＴ０．５ｍｇ／Ｌ。黑暗下３～５天的预培养对愈伤组织上的褐化有明显的抑制作用。雷林一号桉及尾叶桉原生质体分离的最适酶液组合分别为：纤维素酶２％＋离析酶１％＋崩溃酶０．１％;纤维素酶２％＋离析酶１％＋崩溃酶０．０５％。愈伤组织在０．９ｍｏｌ／Ｌ蔗糖溶液中浸泡１ｈ,并于酶解后４ｈ更换一次酶液有利于原生质体产量与活力的提高。淡黄色松散愈伤组织原生质分离效果较其它质地的愈伤组织好。继代后８～１０天愈伤组织作原生质体的分离材料较其它年龄的愈伤组织合适。     

赤桉下胚轴不同再生途径建立研究

赤桉下胚轴不同再生途径建立研究表明，Ｂ５为基本培养基添加２，４－Ｄ１－２ｍｇ／Ｌ及２，４－Ｄ１－２ｍｇ／Ｌ附加ＫＴ０．５ｍｇ／Ｌ可以诱导出愈伤组织，诱导率达１００％；６ＢＡ０．５ｍｇ／ｌ与ＮＡＡ０．２ｍｇ／Ｌ配合使用，可使胚状体发生率达４２．８％。ＮＡＡ３ｍｇ／Ｌｇｎ ６ＢＡ０．２ｍｇ／Ｌ的结合愈伤诱导率也为１００％，例题胚状体发生率只有１７．５％，器官发生率７５．０％。ＡｇＮＯ３０．０５％可促进     

黄竹细胞悬浮培养和原生质体分离*

以牡竹属黄竹（ＤｅｎｄｒｏｃａｌａｍｕｓｍｅｍｂｒａｎｃｅｕｓＭｕｎｒｏ）的竹节及无菌苗根颈为外植体，培养于含有５ｍｇ／Ｌ２，４－Ｄ、０．２ｍｇ／ＬＫＴ和２００ｍｇ／ＬＬＨ的ＭＳ培养基上诱导愈伤组织，然后移至相同成份或不同浓度２，４－Ｄ的液体培养基中，进行悬浮培养，以建立分散性良好的悬浮细胞系。利用悬浮细胞和无菌苗叶片经酶解获大量原生质体，其产量分别约为每克鲜重２．５×１０５个和５×１０５个，活力均可达８０％。     

枣树愈伤组织培养时不定芽的分化

以枣树色白、结构紧密的愈伤组织为材料,对其不定芽的分化情况进行了研究．结果表明,用ＭＳ（ＮＯ－３／２）作基本培养基,并附加ＫＴ４．０００ｍｇ／Ｌ,ＺＴ１．７５０ｍｇ／Ｌ和ＮＡＡ０．０１５ｍｇ／Ｌ可以获得比较好的不定芽分化效果,鸡蛋枣和无核小枣不定芽再生频率分别达到３０％,２２％,其它品种再生频率低于１５％,不定芽在ＭＳ（ＮＯ－３／２）＋ＮＡＡ０．０１５ｍｇ／Ｌ＋ＺＴ１．７５０ｍｇ／Ｌ＋ＫＴ４．０００ｍｇ／Ｌ＋ＡｇＮＯ３２．０００ｍｇ／Ｌ的培养基上能获得最高的增殖系数．     

枣树原生质体分离条件的研究

枣树原生质体分离研究是其原生质体培养与融合、外源遗传物质转化等研究的基础工作．用胚性悬浮培养细胞、细粒状胚性愈伤组织、未细切愈伤组织和已细切愈伤组织等４种材料进行原生质体分离．结果表明,枣树胚性悬浮培养细胞是最佳起始材料,用浓度为１０ｇ／Ｌ纤维素酶＋１ｇ／Ｌ离析酶＋ＣＰＷ盐（１３２０ｍｇ／ＬＣａＣｌ２·２Ｈ２Ｏ和１００ｍｇ／ＬＫＨ２ＰＯ４·Ｈ２Ｏ组成的混合液）＋０．７ｍｏｌ／Ｌ甘露醇组成的混合酶液对起始材料进行１６ｈ的酶解,可获得较高的原生质体产量,且原生质体活力较高．     

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％。     

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．     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.