银腺杨优良无性系HYS-1叶片再生体系的建立

以银腺杨无性系HYS-1组培苗叶片为材料,MS为基本培养基,通过单因素试验及正交试验L16(45),探究不同浓度TDZ、6-BA以及不同生长素种类对银腺杨无性系HYS-1叶片再生体系建立的影响并筛选最佳培养基。结果表明:不定芽主茎高于1cm的芽占总芽数的比率随TDZ浓度的增加而降低。不定芽再生频率随6-BA浓度的增加而降低。在TDZ(0.05~0.10)mg/L+6-BA(0.50~1.50)mg/L的范围内,叶片通过愈伤组织间接诱导大量不定芽,无明显主茎;只有6-BA(0.50~1.50)mg/L时叶片直接诱导不定芽,且主茎明显。叶片基部是最佳不定芽诱导位置;TDZ0.05mg/L+6-BA0.30mg/L+NAA0.05mg/L处理15d后即出现不定芽,且主茎较高,是银腺杨无性系HYS-1叶片诱导不定芽再生的最佳培养基。再生不定芽在1/2MS+0.50mg/LIBA生根培养基上,5d开始生根,生根率95%以上。     

山哈杨三倍体无性系高效再生体系的建立

以山哈杨三倍体无性系的茎段为外植体进行组织培养,研究了不同激素配比对其不定芽诱导分化及生根的影响,确定了其最佳培养基,建立了山哈杨三倍体无性系高效稳定的再生体系。结果表明:最佳的不定芽诱导分化培养基:MS+6-BA0.6 mg/L+TDZ0.01 mg/L+NAA0.02 mg/L,其分化率可达82.2%;生根效果最好的培养基:1/2MS+IBA 0.2 mg/L,生根率达100%。     

杉木优良无性系柳327组培不定根诱导

以杉木（Cunninghamia lanceolata）优良无性系柳327组培继代芽为材料,进行不定根诱导试验,结果表明,IBA对柳327无性系不定根诱导起主导作用,基本培养基起次要作用.将培养了35天,高2.5 ～4 cm的壮芽,扦插于1/2改良ER ＋2 mg/LIBA ＋2 mg/LIAA ＋VC 20 mg/L培养基,培养20天,生根率达97.1％.     

毛白杨无性系85号高效再生系统的建立

应用均匀设计和正交试验筛选出毛白杨无性系85号叶片不定芽诱导最佳组合为MS 0.50 mg/L 6-BA 0.01 mg/L NAA,诱导不定芽生根最适宜的培养基及激素配比为1/2MS 0.50 mg/L NAA 0.05 mg/L IBA.此条件下,叶片平均产生不定芽21.2个,不定芽生根率可达到99%,生根数为7条.该研究为毛白杨无性系85号工厂化育苗和利用叶盘法开展基因转化培育抗逆新品种奠定了良好基础.     

陈山红心杉组培苗诱导不定根研究

以陈山红心杉[Cunninghamia lanceolate(Chenshan-red-fir)]无菌试管苗为材料,研究了不同无性系、基本培养基、生长素、有机添加物等因素对芽苗生根的影响。结果表明,不同无性系组培苗生根诱导率有差异,有机添加物对诱导生根影响不大,陈山红心杉组培苗诱导不定根的适宜培养基为1/2MS+NAA0.5mg/L+IBA 1.0mg/L+20g/L蔗糖+7g/L卡拉胶,其不定根诱导率达88.3%,平均生根数4.12条。     

楸叶泡桐杂种无性系9503的组织培养技术研究

以楸叶泡桐和白花泡桐杂交无性系的枝条为外植体,开展了离体芽增殖技术,以及愈伤组织诱导、芽分化和不定芽生根等组织培养技术的研究。结果表明,增殖培养基采用MS+8mg/L6-BA+0.3mg/LNAA,不定芽的增殖倍数可达到9;利用其叶片进行愈伤组织诱导的最佳培养基为MS+12mg/L6-BA+0.4mg/LNAA,诱导率高达95%;愈伤组织分化的最佳培养基为MS+10mg/L6-BA+0.7mg/LNAA,不定芽生根的最佳培养基为1/2MS+0.5mg/LIBA+0.3mg/LNAA,生根率100%。     

油茶优良无性系组织培养与植株再生

以油茶优良无性系的腋芽为外植体,分别采用附加不同种类激素的MS培养基对其进行组织培养试验,结果表明:不定芽的最佳继代增殖培养基为MS+6-BA0.8 mg.L-1+NAA0.1 mg.L-1,诱导生根最适培养基为1/2MS+IBA0.5 mg.L-1+NAA0.2 mg.L-1,生根率达87.5%。     

杨树诱导芽分化中6-BA和NAA配比优化研究

以杨树无性系LH05-143的叶柄为外植体,利用二次回归正交试验设计对其再生诱导不定芽中的影响因素6-BA和NAA的浓度进行定量优化,实现对再生系统中芽诱导试验影响因子植物激素浓度的优化,同时扩充了再生系统的外植体资料,为再生体系增加了重要的内容。试验结果表明:诱导培养基中6-BA浓度为1.75mg/L、NAA浓度为0.30mg/L时,叶片分化不定芽数可以达2.68;而6-BA浓度为1.74~2.64mg/L,NAA浓度为0.06~0.73mg/L范围内时,有95%的可靠性产生不定芽的叶片分化不定芽数大于1.5。     

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。     

邓恩桉丛生芽的诱导

为了建立优良邓恩桉无性系组织培养与再生体系,为该优良无性系的推广提供大规模的商品化苗木,并在此基础上,进一步建立桉树转基因系统,培育速生耐寒转基因桉树新品种,扩大其栽培区域,以湖南省植物园选育出的优良邓恩桉Eucalyptusdunnii无性系为材料,采取1年生苗上部带饱满腋芽的茎段作为外植体,诱导芽的分化及丛生芽的产生。通过不同质量浓度的生长素NAA和细胞分裂素6-BA的组合对比试验,确定了邓恩桉茎芽分化的最佳培养基为MS 6-BA 0.5 mg/L NAA 0.2 mg/L,芽继代增殖最佳培养基为改良MS 6-BA 0.3 mg/L NAA 0.05 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.