香花油茶天然活性成分茶多酚含量的研究

香花油茶(Camellia osmantha)是2012年在广西南宁发现的油茶新物种。利用没食子酸溶液标准曲线法测定香花油茶嫩芽、嫩叶、成熟叶及果壳茶多酚含量和优质绿茶茶多酚含量,结果表明香花油茶嫩芽的茶多酚含量最高(38.95%),香花油茶果壳茶多酚含量最低(14.49%),茶叶中的茶多酚含量为25.22%。春季的嫩芽含量最高,夏季的嫩芽含量最低;春季成熟叶片含量最高,夏季成熟叶片含量最低。香花油茶有望成为提取茶多酚的新原料。     

超声波-酶法提取油茶多酚的工艺研究

试验采用超声波-酶法提取油茶粕中的多酚,以多酚得率为指标,考察加酶比、料液比、乙醇浓度、温度、时间对油茶多酚得率的影响,在单因素试验结果的基础上,通过三因素三水平响应面分析法对油茶多酚的提取条件做进一步的优化。通过优化所得的最佳提取工艺条件为:加酶比1∶2、料液比1∶23(g/mL)、乙醇浓度55%、温度50℃、时间0.85h,在此条件下多酚得率18.94mg/g。与理论值相比偏差较小,相对误差2%,表明该模型是合理的,可以用来作为油茶多酚提取的最佳工艺条件。     

油茶种质资源评价研究进展

油茶是我国南方主要的木本食用油料树种,对油茶种质资源进行评价,有利于发掘和利用油茶优良遗传性状,促进油茶品种选育与改良.系统地从形态特征的遗传变异、染色体核型分析、优良品种鉴定、遗传多样性分析等方面综述了油茶种质资源研究现状,并对油荼种质资源评价研究前景进行了展望.     

山茶油的市场销售现状分析及建议

正山茶油的价值山茶油(又名野山茶油,茶籽油,油茶籽油)取自油茶树的种籽,具有极高的营养价值。茶油中不但富含不饱和脂肪酸、茶多酚、角鲨烯、维生素E、锌等营养物质,而且还不含有芥酸,胆固醇、黄曲霉素等对人体有害物质。营养价值可与橄榄油相媲美,油茶与油棕、油橄榄、椰子并称为世界四大木本油料植物,也被美称为"东     

种植不同油茶品系实生苗对红壤胞外酶活性的影响

【目的】为了解野生油茶与栽培种油茶对土壤物理、化学、生物性质的影响的差异情况,给栽培种油茶的选育提供一定的科学理论依据。【方法】以红壤土盆栽野生油茶和栽培种赣油1号和赣永6号油茶实生苗,研究了不同品系油茶种植土壤理化性质和酶活性的差异情况。【结果】种植不同油茶品系实生苗对土壤pH值均无影响。种植野生油茶的土壤其有机质、全磷、有效磷和速效钾等养分含量均显著低于种植赣油1号和赣永6号油茶的土壤各养分含量,而栽培种赣油1号和赣永6号油茶的种植土壤中这些养分含量间均无差异。种植赣油1号油茶的土壤铵态氮含量低于赣永6号种植土壤的,但其硝态氮含量却显著高于赣永6号种植土壤的。种植野生油茶的土壤纤维二糖水解酶活性显著高于赣油1号和赣永6号种植土壤的,其增幅分别为18.76%和19.34%,而其土壤中β-1,4-葡糖苷酶和β-1,4-木糖苷酶活性均显著低于赣油1号和赣永6号种植土壤的。种植赣永6号的土壤氮水解酶(β-乙酰葡糖胺糖苷酶和亮氨酸氨基肽酶)的活性显著高于野生油茶和赣油1号油茶种植土壤的,其增幅分别为9.45%、14.34%、8.57%和10.39%,而种植野生油茶和赣油1号油茶的土壤亮氨酸氨基肽酶和β-乙酰葡糖胺糖苷酶活性之间的差异均不明显。种植野生油茶的土壤磷酸单酯酶活性显著低于赣油1号和赣永6号油茶种植土壤的磷酸单酯酶活性,其降幅分别为20.88%和13.91%。【结论】栽培种赣永6号油茶对土壤地力的影响程度比野生油茶和栽培种赣油1号油茶对土壤地力的影响程度大。     

茶多酚对8种植物病原真菌的抑制作用

为了明确茶多酚对8种植物病原真菌的抑制作用,本研究采用菌丝体生长速率法测定了茶多酚对隐地疫霉病菌(Phytophthora cryptogea)、油茶叶枯病菌(Pestalopsis apiculatus)、八角炭疽病菌(Colletotrichum horii)、油菜菌核病菌(Sclerotinia sclerotiorum)、油茶炭疽病菌(Colletotrichum fructicola)、水稻纹枯病菌(Rhizoctorzia solani)、桉树梢枯病菌可可毛色二孢(Lasiodiplodia theobromae)和香蕉枯萎病菌(Fusarium oxysporum)的抑菌作用。结果显示,茶多酚对这些病原菌均有不同程度的抑制作用,抑制作用最好的是Colletotrichum horii,EC50值为12.84 mg/mL,其次是Phytophthora cryptogea,EC50值为16.01 mg/mL,抑制效果最差的是Lasiodiplodia theobromae,EC50值达到了104.35mg/mL。     

油茶蒲药用价值研究现状

指出了茶油的营养价值可与橄榄油媲美,被誉为"油之珍品"、"东方橄榄油"。油茶果的皮叫油茶蒲,作为油茶加工过程中最大的副产物利用率极低,对其生物活性和药用价值的研究十分匮乏。在实际生产中油茶蒲基本被废弃或作为燃料使用,造成了很大的环境污染和资源浪费。综述了油茶蒲在抗氧化、抗肿瘤、降血脂和预防肥胖等方面的药用研究进展。     

油茶抚育管理与茶林放蜂关系的研究

通过对油茶林不同抚育管理水平的调查研究,油茶进行抚育管理是油、蜜丰收关键的营林措施,油茶垦复施肥后可使单位面积开花数量增强,始花和终花时间提前,泌蜜量、蜜质和成果率提高。 利用蜜蜂为油茶授粉,是提高油茶的产量和利用油茶蜜源来保护及繁殖蜂群,增加养蜂收益。为此,我们从1987年开始,在推广油茶花蜜蜂授粉技术的同时,结合油茶丰产林的培育开展了“油茶抚育管理与茶林放蜂关系”的研究,现将结果报告如下:     

淳安县油茶产业发展现状与对策研究

油茶是淳安的传统经济林树种,也是绿化造林的先锋树种。淳安县现有油茶10万亩,由于树龄老化,品种混杂,经营粗放,经济效益低下,制约了油茶产业的发展。近年来,淳安县通过推广油茶良种化、进一步扩大油荼规模、开展原有油茶园改造示范和油茶油品牌建设等措施,油茶产业发展有了明显的提升。目前既有领导高度重视、良好的基础条件和增长潜力、市场前景广阔、集生态观赏经济多功能于一体,尤其是生态景观效益显著等有利条件,也有良种苗木供应不上不利因素。通过广泛宣传油茶的优点和发展油荼的重要意义、科学规划油茶产业、改造现有油茶林努力提高单位面积产量、充分利用林地空间开展山核桃林地油茶生态套种绿化、加快油茶良种繁育基地建设推广油茶优良新品种、发展油茶庭院经济美化乡村环境、改进加工工艺发挥品牌效益、努力拓宽资金渠道等措施,力争到2015年全县油茶基地面积达到15万亩,油茶亩产量实现翻一番,油茶产业产值达到1亿元以上,实现油茶产业可持续发展。     

油茶探源

我国人民很早就认识到油茶为优质油源,茶油为油中上品,对野生油茶林的利用,有两千多年历史,对油茶实行人工栽培,也有近千年。早在唐代,就将油茶生产列为主要农事之一;明代以来,已形成相当生产规模。在长期的生产实践中,我国人民在油茶栽培、收获和榨油技术等方面获得了较大成就。     

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.     

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.     

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。