鼓槌石斛杂交育种及组培育苗技术研究

通过对鼓槌石斛野生种质人工杂交获得蒴果,再以蒴果种子为外植体进行组培快繁和假植育苗试验,结果表明:人工杂交授粉结果率达65.4%;种子萌发及原球茎诱导培养基为1/2Mb+水解乳蛋白1g·L-1+2.5%白糖,萌发率达95%;增殖分化培养基为3/4Mb+NAA0.2 mg·L-1+6-BA0.1 mg·L-1+8%马铃薯泥+4%香蕉泥+3%白糖,增殖倍数达12.6倍;壮苗生根培养基为3/5Mb+NAA0.5 mg·L-1+IBA 0.1 mg·L-1+5%马铃薯泥+7%香蕉泥+0.1%AC+2%白糖,生根率达100%,移栽成活率达96%以上。     

铁皮石斛杂交种组织培养技术试验

以铁皮石斛杂交种子为外植体的组织培养技术试验结果:铁皮石斛杂交种原球茎最佳诱导培养基为3/4Ma+5%椰子汁;增殖分化培养基为3/4Ma+6-BA 0.2 mg·L-1+NAA 0.1 mg·L-1+10%马铃薯泥+2%香蕉泥;壮苗生根培养基为3/4Ma+6-BA 0.2 mg·L-1+NAA 1.0 mg·L-1+8%马铃薯泥+5%香蕉泥,生根率可达100%,移栽成活率在97%以上。     

福建山樱花组织培养试验

以半木质化枝条为外植体,探讨外植体消毒时间、植物生长调节剂对福建山樱花组培各阶段的影响,结果表明:外植体先用75%酒精消毒30 s,再使用0.1%HgCl溶液消毒5 min的消毒效果较好。较适宜的诱导培养基为:MS+6-BA 1.5mg·L-1+NAA 0.1 mg·L-1;较适宜的继代培养基为:3/2 MS+6-BA 1.0 mg·L-1+NAA 0.2 mg·L-1;较适宜的生根培养基为:1/3 MS+IBA 1.0 mg·L-1+NAA 0.2 mg·L-1,生根率达97.4%。生根苗移栽到泥炭土∶珍珠岩∶黄心土(6∶3∶1)的基质中成活率可达90%以上。     

齿瓣石斛原球茎诱导及植株再生技术试验

对齿瓣石斛原球茎诱导及植株再生技术试验的结果表明:齿瓣石斛原球茎最佳诱导培养基为MS+6-BA3.0 mg/L+NAA0.1 mg/L;增殖分化培养基为MS+6-BA 2.0 mg/L+NAA0.5 mg/L;壮苗生根培养基为MS+IBA1.0 mg/L+NAA0.1 mg/L。     

红丝线组织培养技术研究

选用红丝线当年生枝条为外植体,开展红丝线组培快繁技术研究.结果表明,在红丝线组织培养过程中,基本培养基以MS较佳;初代诱导的最适培养基为:MS +6-BA 2.0 mg·L-1,诱导率80％;芽增殖的最适培养基为:MS+ 6-BA 0.5 mg·L-+ NAA 0.05 mg·L-1,增殖系数达5.9;最适生根培养基为:MS+ IBA 0.1 mg·L-1+ NAA 0.3mg·L-1,生根率100％;移栽存活率高达98.6％.     

翅荚木组培快繁技术的研究

以翅荚木的腋芽以及翅荚木幼苗嫩茎为外植体,进行组培快繁技术研究,结果表明:翅荚木适宜的初代培养基为MS+6-BA 1.0 mg.L-1+IBA 0.05 mg.L-1;继代培养基以MS+6-BA 0.5 mg.L-1+IBA0.1 mg.L-1+KT0.5 mg.L-1培养,效果好;生根培养则以MS+IBA0.05 mg.L-1+NAA0.05 mg.L-1+KT0.1 mg.L-1培养基的生根效果最好。     

托里桉组培快繁技术初步研究

以2 a托里桉超级苗不同株系的茎段为外植体进行组培快繁研究,结果表明：适合诱导的培养基为MS改良+6-BA 0.5mg·L-1+NAA 0.1 mg·L-1;适合6号株系增殖培养基为MS改良+6-BA 0.2 mg·L-1+NAA 0.1 mg·L-1,适合7号、10号株系的增殖培养基为MS改良+6-BA 0.3 mg·L-1+NAA 0.2 mg·L-1;适当缩短继代周期是解决桉苗顶稍枯萎、上部叶片脱落等症状简单、有效的方法;适合的生根培养基为1/2MS改良+ IBA 0.2 mg·L-1+ ABT 0.6 mg·L-1,生根苗移栽成活率可达90%。     

红花槐的组识培养与快速繁殖

1 植物名称 红花槐,亦称"毛刺槐". 2 材料类别 二年生枝条茎节. 3培养条件 丛生芽诱导培养基:(1)MS+6-BA2mg.L-1(单位下同)+NAA0.1;(2)MS+6-BA3+NAA0-3+ZT0.01:(3)MS+6-BA1+GA0.1;丛生芽增殖培养基:(4)MS+6-BA2+NAA0.2;(5)MS+6-BA3+NAAO.1:(6)MS+6-BA3+NAA0.3+GA0.1;生根培养基:(7)1,2 MS+NAA0.5;(8)1/2 MS+IBA0.3.以上培养基均添加30g.L-1白砂糖、7g.L-1琼脂条,pH为5.6～5.8.培养温度为25℃,光强约40 umol.m-2.s-1,光照时间12h.d-1.     

矮沙樱桃的组织培养与快速繁殖

以矮沙樱桃幼嫩茎段为外植体进行组织培养试验,筛选出适合矮沙樱桃外植体诱导培养基为MS+6-BA0.8 mg.L-1(单位下同)+IAA1.2,愈伤组织诱导培养基为MS+6-BA1.0+NAA0.1,继代芽分化培养基为MS+6-BA0.8+IAA1.5+NAA0.05,生根培养基为1/2MS+IBA0.5+根皮苷5,以草炭∶蛭石∶珍珠岩=2∶1∶1为移栽基质效果最好。     

草莓新品种"森研99号"的组培快繁技术研究

以“森研99号”草莓新萌发的匍匐茎作外植体,进行组培快繁研究。结果表明:用培养基MS 6-BA1mg.L-1 IBA0.05mg.L-1诱导产生不定芽;用MS 6-BA0.8mg.L-1 IBA0.06mg.L-1作增殖培养基,增殖系数达6.5;用1/2MS IBA0.1mg.L-1作生根培养基,生根率100%,生根整齐,每株苗根数5~10条。试管苗移栽宜选河沙作基质,移栽成活率达90%,生长健壮。     

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.