胶东卫矛组织培养快速繁殖技术研究

以胶东卫矛的茎段为外殖体,研究其再生植株在不同外源激素配比下的适宜培养基.试验结果表明:胶东卫矛茎段启动培养基中以Ms培养基附加BA 2.0mg/L、NAA 1.0mg/L较好,继代培养基以MS培养基附加BA1.0 mg/L、NAA 0.5 mg/L较为合适.生根培养基为1/2MS NAA 0.3 mg/L IBA 0.1 mg/L最佳,生根率高达100%.     

八角组织培养试验初报

以八角顶芽为材料,试验了几种基本培养基对茎段组织培养的影响,并研究了八角茎段组织培养技术.结果表明:0.1%HgCl2消毒12 min效果较好;春季外植体比秋季外植体更适离体培养;MS比1/2 MS、White、MS改培养基适于茎段的萌芽培养,萌动率达27.6%.最适的初代培养基为:MS+IBA1.0 mg·L-1+6-BA3.5 mg·L-1,萌芽率达76.7%.     

厚朴茎段的组织培养

以茎段为初始外植体,以MS为基本培养基,附加不同种类、浓度的生长调节物质,对厚朴茎段快速繁殖进行研究。结果表明:适宜初代、继代培养基为1/2MS,附加BA 1.0mg/L和NAA 0.5mg/L,生根培养基为1/2MS+NAA 1.0mg/L。     

库拉索芦荟的组培与快繁研究

以MS为基本培养基，库拉索芦荟的幼嫩的基茎为植体，进行离体培养，表明分化培养基以6-BA2mg/1 NAA0.mg/I最佳，生长培养基以MS NAA0.1mg/L较好。     

余甘子丛生芽诱导和快速繁殖研究

本试验以余甘子嫩芽和嫩枝茎段为外植体 ,在 MS培养基中进行离体繁殖和培养试验。结果表明 ,添加细胞分裂素 BA对丛生芽诱导有明显促进作用 ,激素组合以 BA与 NAA为最好 ,嫩芽外植体诱导丛生芽的最适培养基为 MS BA0 .5 mg/ L NAA 0 .1mg/ L,分化率达 90 %以上 ;嫩枝茎段旅导丛生芽所需的 BA浓度相对高些 ,最适培养基为 MS BA 2 .0 mg/ L NAA 0 .1mg/ L,分化率达 5 6 .7% ,丛生芽增殖生长培养基为 MS BA 0 .1mg/ L NAA 0 .1mg/ L Na H2 PO45 0 mg/ L。生根培养基为 1/ 2MS NAA 0 .2 5 mg/ L IBA 0 .2 5 mg/ L ,生根率在 30 %左右     

圣诞树组织培养快速繁殖技术研究

以圣诞树的茎段为外植体,研究其再生植株在不同外源激素配比下的适宜培养基。试验结果表明：圣诞树茎段启动培养基中以MS培养基附加6-BA2.0㎎/L、NAA1.0㎎/L较好,继代培养基以MS培养基附加6-BA1.0㎎/L、NAA0.5㎎/L较为合适。生根培养基为1/2MS＋NAA0.3㎎/L＋IBA0.1㎎/L最佳,生根率高达98﹪     

钙果苗木组培技术初探

以钙果带2个腋芽的茎段为外植体进行快速繁殖,结果表明,基本培养基都以改良的MS为最好,筛选出各培养基分别为:(1)侧芽萌动,1/2MS 5%椰子乳为培养基是最好,茎切段在该培养基上萌芽快,且侧芽长而粗壮;(2)分化及继代,MS 5%椰子乳 6-BA(0.3～0.6)mg/L NAA 0.01mg/L为培养基是最适合的;(3)生根,1/ 2MS 1%椰子乳 IBA 2.5mg/L为培养基,试管苗生长良好,有利于钙果的生根。     

丽格海棠外植体组织培养的研究

以丽格海棠的叶片、叶柄和茎段作为外植体进行组织培养,研究适宜丽格海棠组织培养的最佳外植体、不同部位外植体不定芽分生的最佳培养基、继代增殖的培养基和组培苗的生根培养基。结果表明:不同部位外植体不定芽的再生率:叶片>茎段>叶柄,叶片的最佳培养基为:MS+1mg/LTDZ+0.1mg/L2,4-D或MS+1mg/L6-BA+0.1mg/LTDZ,叶柄的最佳培养基为:MS+1mg/L6-BA+0.1mg/LTDZ,茎段的最佳培养基:MS+1mg/LTDZ+0.1mg/L2,4-D或MS+1mg/L6-BA+0.1mg/LTDZ;不定芽继代增殖的最佳培养基为MS+2mg/L6-BA+0~0.1mg/LNAA;组培苗生根的最佳培养基比为MS+0.1~0.3mg/LIBA。     

外源激素对大花蕙兰组织培养的影响

以茎尖为外殖体进行大花蕙兰组织培养,研究表明：大花蕙兰茎尖在MS＋6-BA1.5mg/L＋NAA0.1mg/L培养基上培养25d后,茎尖分化形成原球茎;原球茎在1/2MS＋6-BA2.0mg/L＋NAA0.1～0.2mg/L培养基上增殖速度最快,增殖系数可达7.62;原球茎在1/2MS＋NAA0.2mg/L培养基上分化最好,分化的大花蕙兰幼苗在1/2MS培养基上生根效果好。     

蝴蝶兰花梗组织培养快速繁殖

通过组织培养的方法诱导蝴蝶兰花梗上的休眠芽萌发,可以得到无菌的蝴蝶兰丛生芽。以无菌丛生芽上的幼叶和茎尖、腋芽为外植体,进行组织培养,建立起蝴蝶兰的无菌培养体系。诱导休眠芽萌发的培养基为MS BA5;利用幼叶进行原球茎诱导的培养基为1/3MS Hyponex3.5g KT10 NAA0.1;利用茎尖和腋芽进行原球茎诱导的培养基为MS BA3 柠檬酸30mg.L-1;原球茎增殖的培养基为1/3MS BA2 KT0.5 NAA0.1 椰乳200ml,也可以利用原有的初代培养基;生根培养基为1/3MS Hyponex3.5g NAA0.1 IBA0.1 胰蛋白胨2g 香蕉200g。     

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.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

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。