油茶12个物种花药愈伤组织诱导及继代培养

选择12个油茶物种进行花药愈伤组织的诱导,以小果油茶、普通油茶、短柱油茶、浙江红花油茶、茶陵红花油茶、多齿红花油茶诱导率较高,在40％～70％之间,其中小果油茶、普通油茶的愈伤组织诱导率高达70％。红皮糙果油茶、广西糙果油茶、茶陵红花油茶、多齿红花油茶、攸县油茶花药褐化较严重。继代培养中6-BA和KT均有较好的促进作用,小果油茶、普通油茶、短柱油茶、浙江红花油茶、茶陵红花油茶、多齿红花油茶的愈伤组织均增殖较好。油茶花药培养应以小果油茶、普通油茶、短柱油茶、浙江红花油茶、茶陵红花油茶、多齿红花油茶作为进一步试验的基本材料,开展下一步的愈伤组织增殖和脱分化试验。     

油茶两物种花药培养愈伤组织诱导试验

对小果油茶和广宁红花油茶的花药进行离体培养,并诱导形成愈伤组织。试验结果表明,广宁红花油茶花药具有很强的愈伤组织诱导能力,而小果油茶褐化严重,诱导率很低。培养基及其激素种类与浓度组合对愈伤组织诱导有很大影响,且两种油茶表现出一致性,在最好的MS+2,4-D0.6mg·L-1+NAA0.4mg·L-1和B5+2,4-D1.2mg·L-1+6-BA0.4mg·L-1培养基中,广宁红花油茶诱导率高达94.67%和91.00%,小果油茶则分别为8.00%和3.34%。低温预处理6～12d有助于提高诱导率。MS培养基有利于愈伤组织生长增殖。还就小果油茶花药褐化等问题进行了讨论。     

广西油茶物种和品种类型简介

广西地处亚热带,气候温暖,雨量充沛,地形复杂,山岭绵延,丘陵起伏,石山林立,群峰错综分布,土壤肥沃深厚,油茶物种繁多。根据其开花颜色的不同,可分为白花油茶、红花油茶和黄花油茶三大类。其中以白花油茶种类最多,有普通油茶、小果油茶、陆川大果油茶、博白大果油茶等物种;红花油茶有广宁红花油茶、宛田红花油茶等物种;黄花油茶有金花油茶、凹脉金花茶、薄叶金花茶、东兴金花茶和显脉金花茶等物种。除久经栽培、面积较大的普通油茶(中果油茶)小果油茶、陆川大果油茶外,其它物种都处于零星栽培或处于     

不同培养条件对油茶花药愈伤组织形成的影响

为了提高油茶花药培养的愈伤组织诱导率,以普通油茶、小果油茶、浙江红花油茶、广宁红花油茶为试验材料,初步研究了不同蔗糖质量浓度、培养基类型、琼脂用量、取材时期、是否光照培养及培养基是否添加活性炭等不同的培养条件对油茶花药愈伤组织形成的影响,来筛选较为适宜的培养条件．研究结果表明,在盛花初期所采样品的愈伤组织诱导率高于盛花末期所采样品的诱导率;以MS琼脂固化培养基、蔗糖质量浓度30～40g·L~(-1)为最佳的油茶花药愈伤组织的诱导培养基配方;在黑暗条件下培养可以提高油茶花药愈伤组织的诱导率．     

6个油茶物种的光合特性

为了更好地对油茶种质资源加以利用,于10月份使用Li6400便携式光合作用测定系统对定植于广西南宁的普通油茶、香花油茶、博白大果油茶、广宁红花油茶、日本红山茶和南荣油茶共6个油茶物种的光合特性进行了研究。结果表明,不同物种光合特性存在较大差异。其中,普通油茶光合效率最高,日平均净光合速率达到7.24μmol.m-2s-1,日平均净光合速率最小的宛田红花油茶光合速率仅为普通油茶的51.52%,日平均净光合速率由大到小依次为普通油茶、香花油茶、博白大果油茶、广宁红花油茶、日本红山茶、宛田红花油茶。在模拟光辐射条件下,6个油茶物种最大净光合速率在8.4～10.5μmol.m-2s-1之间,普通油茶最高,宛田红花油茶最低;普通油茶的光补偿点仅为15.50μmol.m-2s-1,利用弱光的能力最强;香花油茶的光饱和点为499.7μmol.m-2s-1,利用强光的能力最强。     

红花油茶营养成分分析及评价

为了全面了解我国主栽红花油茶品种的品质特点与加工特性,选择目前已规模化种植且种植面积较大的浙江红花油茶、腾冲红花油茶和广宁红花油茶的果实为原料,对其果皮、籽壳、种仁中的粗脂肪、还原糖、可溶性总糖、黄酮、多酚等营养成分进行了测定和方差分析、相关性分析与主成分分析。测定结果表明:其油脂主要集中分布于种仁中,浙江红花、腾冲红花、广宁红花油茶种仁中的脂肪含量分别为68.53%、58.58%、60.96%;可溶性总糖含量在15%~24%之间,且在油茶果各组成部分中的分布相对均较均匀;黄酮在果皮和籽壳中的含量均较丰富。3种红花油茶种仁中各种营养成分之间的相关性分析结果表明:其脂肪含量与可溶性总糖含量间均呈显著负相关,而与多酚、黄酮含量之间均呈不显著正相关;浙江红花油茶种仁中的脂肪含量与还原糖含量之间呈显著正相关,广宁红花油茶种仁中的脂肪含量与还原糖含量之间则呈不显著负相关。主成分分析结果表明:浙江红花、腾冲红花和广宁红花油茶种仁营养成分的综合评分分别为18.05、13.24和15.05,这一结果说明,浙江红花油茶种仁的营养价值较好。     

亚热带北缘浙江红花油茶和腾冲红花油茶引种成功

亚热带北缘浙江红花油茶和腾冲红花油茶引种成功薛海兵，李玉善（西北植物研究所，陕西杨陵７１２１００）浙江红花油茶和腾冲红花油茶不仅含油率比普通油茶高出５％～１０％，同时，其花大红艳，初春开花花期长，具有较高的观赏价值。我们于１９７８年３月从浙江、云南引...     

浙江红花油茶的封闭育苗方法研究

<正> 浙江红花油茶又名红山茶 Camelliachekiungoleasa Hu)为常绿灌木或小乔木,是我国特有的既可观赏又可油用的经济树种。我所自1965年引进浙江红花油茶以来,又先后引进宛田红花,腾冲红花,小叶红花,广宁红花,恩施红花,寒陵红花等品种。生长正常,栽后4-5年就开花结果,其     

广西主要油茶物种的脂肪酸组成研究

油酸含量是评价食用油营养水平的重要依据。对广西油茶主要物种脂肪酸组成进行分析研究,结果表明:油茶物种不同,油酸含量存在明显差异,普通油茶油酸平均含量最高,其次是宛田红花油茶、越南义安油茶、广宁红花油茶、陆川油茶、博白大果油茶;物种相同,油酸含量变幅范围也较大;各脂肪酸组成之间存在一定的相关性。     

金花茶与部分山茶属植物杂交育种初报

为探讨金花茶(Camellia chrysantha)与其他山茶属植物的杂交育种亲和性,培育出利用价值高的杂交金花茶新品种,开展金花茶与宛田红花油茶(C.polyodonta)、越南抱茎山茶(C.amplexicaulis)、广宁红花油茶(C.semiserrata)、普通油茶(C.oleifera)无性系岑软3、博白大果油茶(C.gigantocarpa)、黑牡丹茶花(Heimudan)等山茶属植物杂交育种试验,采用常规杂交育种方法,共设计18个杂交组合。结果表明:有10个杂交组合可以结实,不同杂交组合结实率存在一定差异,其中金花茶66号×宛田红花油茶1号(组合L5)结实率最高(63.64%),金花茶1号×宛田红花油茶2号(组合L6)结实指数最高(15.21)。杂交果的果形、单果鲜重、果高、果径、果皮厚、单果籽粒数、单果籽鲜重与母本无显著差异,与父本有显著差异。试验表明普通金花茶与宛田红花油茶具有较高的亲和性,与越南抱茎山茶亲和性不高,与广宁红花油茶、岑软3、黑牡丹具有一定的亲和性。     

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.     

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。     

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.