二叉鹿角蕨商品化育苗技术研究

珍贵观赏植物二叉鹿角蕨（ＰｌａｔｙｃｅｒｉｕｍｂｉｆｕｒｃａｔｕｍＣ．Ｃｈｒ．）的批量生产,有两种途径：孢子繁殖法和组织培养法。孢子播种基质的种类对二叉鹿角蕨孢子萌发有一定影响,但影响孢子萌发的主要因素是温度和湿度。用组织培养方法,进行孢子无菌播种,孢子萌发对培养基要求并不专一,但培养基中激素种类和浓度以及糖的含量对孢子萌发后原叶体生产及发育成幼孢子体均有一定影响。用二叉鹿角蕨幼孢子体的茎尖和叶片进行组织培养,同样能获得二叉鹿角蕨小苗。     

薇菜孢子育苗技术研究

通过对薇菜孢子萌发的土壤、温度、湿度、光线等因素的筛选，研究薇菜原叶体和孢子体萌发的适宜条件、薇菜孢子播种以孢子采集后5～15d；培养基质为腐殖土、温度25～30℃、湿度80％～90％为最佳。     

珍稀濒危植物桫椤组培技术研究

以孢子为外植体，开展桫椤组织培养快繁技术研究。结果表明：以赤霉素短时间处理桫椤孢子，对其萌发具有促进作用；用50 mg·L^-1GA₃乙醇溶解液处理3 min的桫椤孢子萌发效果最好，萌发率达43.75%,萌发所需时间约30 d;在1/6 MS或1/8 MS中加入6-BA 0.04 g·L^-1和IAA 0.02 g·L^-1,可以显著提高桫椤孢子萌发率和缩短萌发所需时间；原叶体增殖的适宜培养基是1/2 MS,植物生长调节剂会抑制桫椤原叶体的增殖；原叶体分化的适宜培养基为1/2 MS,经4～5次转接后能分化出幼孢子体；桫椤孢子体增殖、生根的适宜培养基均为1/2 MS;桫椤幼苗的移栽成活率较高，可达70%以上。     

观赏苔藓植物的组织培养

实验用改良的Knop营养液配方制液体配养基,在液体培养基上接种消毒的孢子,孢子萌发产生原丝体,用离心机制备纯的原丝体片段,原丝体片段接种于用营养土和蛭石1∶1比例所配制的培养基质上,第56d时基质表面约90%的区域被配子体所覆盖。经叶片解剖形态观察,人工培养的配子体与野外所采集的配子体无明显生境差异。实验探索了以原丝体为实验材料的配子体大规模培养和快速繁殖的方法。     

武夷山自然保护区蕨类植物物种多样性与区系的研究

在野外调查和整理资料的基础上 ,调查分析了武夷山自然保护区蕨类植物的区系组成和分布类型。结果表明 :福建武夷山国家级自然保护区共有蕨类植物 4 0科、92属、2 95种和 9变种 2变型 ;主要科为鳞毛蕨科、水龙骨科、金星蕨科、蹄盖蕨科、铁角蕨科、卷柏科、凤尾蕨科 ,主要属为鳞毛蕨属、铁角蕨属、蹄盖蕨属、卷柏属、复叶耳蕨属、凤尾蕨属、瓦韦属。具有10个分布区类型 ,科的分布类型以泛热带分布及其变型为主 ;属以泛热带分布及其变型为最多 ;种类以东亚分布类型和特有成分为主 ,表现出亚热带的特点。与周边 7个地区蕨类植物区系相似性和丰富度的比较表明 ,与武夷山蕨类植物区系亲缘关系最近的是安徽九华山 ;武夷山的蕨类丰富度比纬度位置高的江西庐山、安徽黄山和浙江天目山大。武夷山拥有 92种中国特有蕨类及一些珍稀蕨类植物 ,有很高的保护价值     

蕨莱人工栽培技术

1 形态特征及适生条件蕨菜(Pteridium aquilinum(L.)Kuhn)是凤尾蕨科的一种多年生草本蕨类植物,生活力很旺盛。幼茎有紫色、绿色和介于二者之间的3种类型。地下有直径1 cm左右的黑色根茎,在地中横走,很大;地上茎(羽柄)高60～100cm,有     

江西上饶灵山蕨类植物资源分析

于2020年,采用野外调查和资料收集的方法,对江西省上饶市灵山国家级风景名胜区的蕨类植物资源种类组成、资源类型进行调查、分析。结果表明：灵山有蕨类植物资源18科、44属、75种(含变种),分别占中国蕨类植物总数的47.37%、24.86%、3.52%,占江西蕨类植物总种数的17.32%。优势科为凤尾蕨科、蹄盖蕨科、卷柏科、金星蕨科、鳞毛蕨科和水龙骨科;优势属为卷柏属、凤尾蕨属和金星蕨属。资源类型可分为药用蕨类植物、观赏蕨类植物、食用蕨类植物、指示蕨类植物、工业原料蕨类植物、饲料和绿肥蕨类植物及农药蕨类植物等7大类,以药用蕨类植物为主,其次为观赏蕨类植物。并提出开发与保护的一些建议。     

白桦雌雄花发育周期的时序特征

以20～30年生白桦的雌雄花序为材料,研究东北地区白桦花发育的生殖周期和发育时序特征.结果表明:雌花序出现于4月中下旬,5～10 d后开始受粉,持续1周左右; 大孢子母细胞于5月中旬开始减数分裂,3～4 d后形成大孢子,功能大孢子继续发育,成熟胚囊在5月底产生,并进行受精,6月初开始胚胎发育,8月中下旬种子成熟.雄花序出现于5月底,比雌花序晚1个月左右; 小孢子母细胞于7月中旬开始减数分裂,8月中旬结束,历时近1个月; 白桦的雄配子体发育很特殊,在当年不形成成熟的雄配子体,以单核小孢子状态宿存于雄花序中越冬,直到第2年4月中下旬才发育成熟,形成具有2核或3核的成熟花粉,随即散粉.雌花受粉时的花粉来源于前1年出现、宿存越冬、第2年4月底开始散粉的雄花.通过比较,建立东北地区白桦雌雄花生殖周期时序特征表,并对白桦雌雄花发育的时序特点进行讨论.     

天女木兰小孢子发生及雄配子体发育的观察

天女木兰是珍稀濒危植物,为给其有效保护措施的制定提供参考,从小孢子发生和雄配子体的发育角度探讨天女木兰濒危原因。研究结果表明,天女木兰花药具有4个小孢子囊,花药壁5～8层。四分体排列方式为平面对称型、四面体型和直线型,其中直线型较少;成熟花粉粒为二细胞型花粉粒;能育花粉率最高达84.9%。通过对天女木兰小孢子发育过程的研究发现,四分体时期有2种不正常类型,说明天女木兰小孢子发育过程中存在异常现象,这是导致天女木兰濒危的原因之一,但不是主要原因。     

南酸枣大小孢子发生及雌雄配子体发育过程研究

[目的]观察南酸枣雌雄配子的发育过程,初步探究南酸枣雌雄蕊败育的发生原因。[方法]利用石蜡切片观察法研究南酸枣的大小孢子和雌雄配子体的发育过程。[结果](1)南酸枣雌雄异株、单性花,雄花无子房,雌花具退化雄蕊;雄花纵长大于3 mm时,花药成熟,子房纵长达3.5 mm时,胚囊成熟;(2)雄花成熟花药壁共分5层,由外向内为1层表皮、1层药室内壁、2层中层、1层绒毡层,发育形式属基本型;(3)小孢子母细胞分裂形式属同时型,四面体型小孢子四分体,2-细胞型花粉,见3个萌发孔胞质囊;(4)双珠被、厚珠心;胚囊发育类型为蓼型,后期倒转;(5)雌花退化雄蕊的花药壁5层,雌花具左右对称型小孢子四分体,小孢子期绒毡层解体,小孢子解体后花药空囊,药室内壁略纤维状加厚,表皮此时退化;(6)南酸枣雄花从现蕾到散粉约25 d时间,雌花从现蕾到胚囊成熟约24 d时间。[结论]南酸枣雌雄配子发育模式与漆树科大多数种一致;雄花无雌蕊,系花芽发育过程中雌蕊原基退化所致;南酸枣未见退化胚珠,雌花退化雄蕊具正常的小孢子母细胞、异常的小孢子四分体和小孢子,且绒毡层不正常解体,花药空囊,无花粉粒。     

Free radical-scavenging activity of aqueous extract of Pteris multifida Poiret

Aqueous extract of Pteris multifida showed scavenging activities on DPPH, hydroxyl radicals and reducing power.     

Two new pterosin dimers from Pteris mutifida Poir

Two new C₁₄ pterosin dimers, which are a pair of isomers named as bimutipterosins A (1) and B (2), were isolated from the whole plant of Pteris multifida. Their structures have been elucidated on the basis of NMR and MS data. From a biogenetic point of view, these compounds including a cyclobutane basic core should be considered as a [2 + 2] dimerization product of dehydropterosin Q, which was a known compound and also isolated from this plant. This novel type of pterosin dimer was reported here for the first time. Compounds 1 and 2 showed cytotoxicity against HL 60 cell line (human leukemia) with the IC₅₀ values of 12.8 and 26.6 μM, respectively.     

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.