三倍体毛白杨愈伤组织诱导及腋芽增殖技术研究

以三 本毛白杨试管苗叶片作为外植体进行愈伤组织的诱导，最适的愈伤组织诱导培养基为MS＋NAA1.0mg/L 6-BA0.1mg/L；分化培养基为：1／2MS＋BA0.5mg/L。利用腋芽增殖试管苗，单芽增殖有效苗可达12株以上；生根培养基为MS＋IBA0.8-1.2mg/L，试管苗的生根率可达85.93%；炼苗成活率达到93.8%，田间移栽成活率为87.5%。     

金焰彩栾组织培养技术研究

通过正交试验等方法开展的金焰彩栾离体培养技术研究结果表明:从金焰彩栾播种后生长3个月的苗上选取外植体,经过0.1%Hg Cl2消毒5 min,灭菌成活率为86.8%;改良MS培养基附加BA,NAA,IBA、IAA等植物生长调节剂可有效促进试管芽苗增殖和生根,其中BA 0.02 mg/L+IBA 0.02 mg/L+NAA 0.03 mg/L+IAA 0.08 mg/L组合培养基为最适宜的继代培养基,增殖倍数达3.8,生长高度为4.8 cm;带根试管苗移栽于泥炭(V)∶黄心土(V)=6∶4的混合基质,控制温度23~30℃,相对湿度85%,保湿10~15 d,其间适当遮荫,20 d后成活率达92.8%。     

花叶络石离体快繁技术研究

花叶络石是攀援、垂直等立体绿化好材料,具有较高观赏价值。通过正交试验等方法对花叶络石茎段组织培养外植体灭菌、玻璃苗预防、增殖培养、根诱导等关键技术进行研究。结果表明:在镇江句容花叶络石的最佳取材时间为4月中下旬,在引进日本种源中筛选优良类型的母株上选取外植体,经过用0.1%HgC l2消毒灭菌10 s,成活率为80.5%;添加3.5%的白砂糖和增加培养容器的透气性,能很好地预防玻璃苗的发生;MS附加TDZ、BA、NAA等植物生长调节剂可有效促进试管芽苗增殖和生长,其中TDZ 0.01 mg/L BA 2.0 mg/L NAA 0.01 mg/L组合最适宜增殖与生长,增殖倍数达5.6,生长高度为2.8 cm;适宜的生根培养基为1/2MS IBA 0.5 mg/L NAA 0.3mg/L CH 100 mg/L S 2%,生根率可达95%;经生根的试管苗移栽于蛭石(V)∶珍珠岩(V)∶泥炭(V)=6∶3∶1的混合基质中,控制温度20~30℃,相对湿度85%~90%,保湿15~20 d,其间适当遮荫,22 d后成活率91.5%以上。     

照山白杜鹃组织培养研究

以照山白杜鹃(Rhododendron micranthum)试管苗的茎段为外植体,研究不同激素组合对其外植体诱导、丛生芽增殖及试管苗生根的影响.结果表明:最适丛生芽诱导培养基为Read+ ZT 4.0 mg/L+ NAA 0.05 mg/L+蔗糖(3％),诱导率达92.41％;最适丛生芽增殖培养基为Read+ ZT 3.0 mg/L+ NAA 0.1 mg/L+蔗糖(3％),增殖系数达7.56;生根培养基为Read+ IAA 0.5mg/L+蔗糖(2％),生根率达92.5％;NAA不适宜照山白杜鹃生根诱导;将试管苗移栽到松毛土∶泥炭土∶河沙=1∶2∶1的基质中,成活率达89％.     

美花红千层的组织培养研究

以美花红千层茎段为外植体,进行腋芽诱导以及增殖、生根、炼苗移栽试验,以建立高效的美花红千层离体快繁体系。结果表明:以美花红千层单芽茎段在MS+6-BA0.5mg/L培养基上萌芽效果最好,芽诱导率为87%;试管苗在改良MS(NH4NO3减半)+6-BA0.3mg/L+NAA0.1mg/L培养基上继代效果最好;试管苗在1/2MS+IBA0.3mg/L+NAA0.1mg/L培养基上生根效果最好,生根率为99.3%;试管苗经炼苗,移栽至珍珠岩和腐质土3∶1混合基质中成活率最高,为95%。     

牡丹石榴的组培快繁技术研究

取牡丹石榴春季嫩芽作外植体，进行离体快速繁殖，筛选出最佳增殖、生根培养基，确定了试管苗移栽的最佳基质。培养基MS＋BA0.7mg/L IBA0.15mg/L增殖生长的最佳培养基，增殖系数为5.7；培养基1／2MS＋NAA0.1mg/L对牡丹石榴试管苗生根培养较适合，生根率为91.4%；在塑料小拱棚中利用蛭石为移栽基质，移栽成活率可达86 .7％。     

北美枫香“秋霞红”组织培养快速繁殖技术研究

通过正交试验等方法对北美枫香"秋霞红"组织培养技术进行了研究。结果表明:在江苏扬州最佳取材时间为4月下旬,选取外植体,经过0.1%Hg Cl2消毒12 min灭菌,成活率为78.7%;添加VC35 mg/L能有效预防试管苗褐变的发生,增加培养容器的透气性可减少试管苗玻璃化发生;2/3MS附加TDZ、BA、NAA等植物生长调节剂可促进试管苗增殖和生长,其中TDZ 0.2 mg/L+BA 1.0 mg/L+IBA 0.1 mg/L+VC35 mg/L组合最适宜增殖与生长培养,增殖倍数达4.5,生长高度为3.8 cm;适宜的生根培养基为1/3 MS+IBA 0.5 mg/L+NAA 0.3 mg/L+AC 3 000mg/L+S 2%,生根率可达92%;经生根的试管苗移栽于泥炭、黄心土为7∶3(V∶V)的混合基质,控制温度23~30℃,相对湿度90%,保湿12~18 d,其间适当遮荫,30 d后成活率达90.8%。     

南洋楹组培快繁技术优化研究

以南洋楹优树种子无菌苗单株作为初始外植体,通过均匀设计和正交设计试验筛选培养基配方,并对诱导增殖流程、培养条件、炼苗等技术环节进行了优化研究,建立南洋楹无性系规模化组培快繁技术。结果表明:南洋楹外植体在诱导培养基MS+6BA 0.5 mg/L诱导分化2周期后,转入增殖培养基MS+6BA 0.2 mg/L+NAA0.02 mg/L+蔗糖30 g/L,采用自然光源培养4周期,可显著抑制玻璃化现象,增殖倍数达4.1;生根培养基为1/2MS+NAA 0.01 mg/L+IBA 0.2 mg/L+蔗糖20 g/L,生根率72.3%;将生根与炼苗过程结合进行可增强植株抗性,移栽成活率提高至92.5%。     

木鳖子茎蔓无菌培养及植株再生研究

以木鳖子幼嫩茎蔓为外植体进行组织培养研究,结果表明,最适宜的诱导培养基为MS+6-BA 0.8 mg/L+NAA0.1 mg/L+蔗糖30 g/L,诱导率为66.7%;继代增殖培养基为MS+6-BA 0.6 mg/L+NAA 0.2 mg/L+马铃薯泥2%+活性炭1 g/L+蔗糖30 g/L,增殖倍数为5.6倍;生根培养基为MS+NAA 0.4 mg/L+香蕉泥5%+活性炭2 g/L+蔗糖20 g/L,生根率100%,平均生根数4.8条,平均根长3.9 cm。炼苗10 d后移栽腐殖土∶火烧土∶腐熟艾蒿(体积比5∶3∶2)混合基质的成活率最高达93.3%。     

龙脑樟愈伤组织诱导及增殖研究

以龙脑樟的茎段作为外植体,进行腋芽的诱导获得无菌苗,继而腋芽小叶被用于愈伤组织的诱导并进行增殖培养。结果表明外植体适宜的灭菌方法为：0.1%升汞灭菌10 min,污染率为21.6%;腋芽小叶愈伤组织诱导最佳培养基配方为：MS＋BA 4.0 mg/L＋NAA 0.1 mg/L,诱导率可达72.7%,较佳增殖培养基组合为：MS＋BA 5.0 mg/L＋NAA 0.5 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.