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1.
银杏酚酸类物质防治农业害虫的研究 总被引：15，自引：0，他引：15
银杏酚酸类物质即银杏酸、银杏酚和白果酚是从银杏(Ginkgo biloba L.)外种皮中分离得到的杀虫活性成分。利用银杏外种皮粗提物配制的生物农药，具有广谱防治农业害虫的作用。 相似文献
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银杏外种皮中银杏酚酸类物质防治农业害虫试验初报 总被引：5，自引：0，他引：5
从银杏外种皮中分离到的银杏酚酸类物质具有杀虫活性，利用银杏外种皮粗提物配制的生物农药，对多种蚜虫及蓟马、菜青虫等农业害虫具有防治作用。 相似文献
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将富马海松酸三(β-丙烯酰氧基乙基)酯(FATE)通过自由基聚合反应键合到烷基化硅胶(TPM-SiO2)表面，制备了核壳型松香基高分子键合硅胶(RP@SiO2)固定相，对RP@SiO2固定相进行了一系列表征和评价，探讨了RP@SiO2柱对紫杉醇(PTX)及其类似物的分离性能和分离机理，并将其用于红豆杉树皮粗提物中PTX的分离纯化。结果表明：FATE成功键合在硅胶表面，核壳型结构材料成功制备，RP@SiO2的平均粒径约为5μm; RP@SiO2柱是类似于C18柱的典型反相色谱柱，表现出优异的色谱性能、良好的重现性和典型的反相色谱行为；采用RP@SiO2柱分离紫杉醇类似物，连续洗脱样品的分离度均超过6.6。计量置换保留理论(SDT-R)和van’t Hoff热力学分析结果表明：疏水相互作用决定了分析物的保留，在RP@SiO2柱上分离紫杉醇类似物是一个焓驱动的放热过程，SDT-R可用于解释其保留机理。采用RP@SiO<... 相似文献
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《林产化学与工业》2018,(2)
采用硅胶柱层析法对臭蒿粗提物进行分离纯化,利用孢子萌发法对抗菌流分进行活性评价,采用高效液相色谱-质谱联用技术(HPLC-MS)分析抗菌流分的物质组成。结果显示:臭蒿粗提物分离纯化得到13种流分(Fr.1~Fr.13),其中流分Fr.5抗菌活性最好,对流分Fr.5进一步硅胶柱层析分离得到4种流分(Fr.5.1~Fr.5.4)。臭蒿粗提物对烟草链格孢菌孢子的EC50为5.04 g/L,流分Fr.5.2的EC50为0.57 g/L。LC-MS分析出流分Fr.5.2主要由去氧双羟基蒿甲醚(17.00%)、去氧双氢青蒿素(43.65%)、去氧青蒿素(16.15%)组成。以双氢青蒿素为标准品,测得流分Fr.5.2中双氢青蒿素的质量分数为40.95%,双氢青蒿素对烟草链格孢菌孢子的EC50为2.70 g/L,表明流分Fr.5.2中主要抗菌物质为青蒿素衍生物。 相似文献
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以银杏鲜叶(样品1)、银杏干叶(样品2)和银杏陈叶(样品3)为原料，制备了3个样品的乙醇提取物，采用HPLC-DAD-MS法分析3个样品中银杏叶色素类化合物的组成；通过液液萃取、硅胶柱层析和HPLC制备色谱等技术手段对样品2和样品3的银杏叶色素类化合物进行了分离纯化和结构鉴定。从3个样品中初步推测出24种银杏叶色素类化合物，其中叶绿素类化合物17种，类胡萝卜素类化合物7种。从样品2和样品3的乙醇提取物浸膏中分离纯化出10种银杏叶色素单体化合物，通过质谱、紫外光谱、红外光谱和核磁共振氢谱数据分析，并结合文献对照鉴定化合物分别为：β-胡萝卜素(A)、脱镁叶绿素a(B)、脱镁叶绿素b(C)、叶黄素(D)、植基紫红素18a(E)、焦脱镁叶绿素a(F)、 132-羟基脱镁叶绿素a(G)、 132-羟基脱镁叶绿素a′(H)、 132-羟基脱镁叶绿素b(I)、 132-羟基脱镁叶绿素b′(J),其中E、F、G、H、I、J为首次从银杏叶中分离得到。 相似文献
7.
对土耳其掊子的抑菌活性成分进行研究。采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、制备薄层色谱、HPLC,对土耳其掊子中的化学成分进行分离,通过理化性质和光谱数据鉴定其结构,采用抑菌试验对土耳其槽子不同提取部位和单体化合物进行抑菌活性筛选。分离得到7个化合物,分别鉴定为：没食子酸（Ⅰ）、间-二没食子酸（Ⅱ）、对-二没食子酸（Ⅲ）、没食子酸甲酯（Ⅳ）、没食子酸乙酯（Ⅴ）、1,2,3,6-四-O-没食子酰基-β-D-葡萄糖（Ⅵ）和1,2,3,4,6-五-O-没食子酰基-β-D-葡萄糖（Ⅶ）。土耳其桔子乙酸乙酯部位含主要抑菌活性成分,其中化合物Ⅲ和Ⅴ均为首次从该桔子中分离得到。 相似文献
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楸树叶中抗氧化活性成分的分离和鉴定 总被引：1，自引：0，他引：1
前期研究发现,楸树叶粗提物的乙酸乙酯萃取相具有较强的抗氧化活性。为了进一步明确其抗氧化活性成分,以硅胶柱色谱结合清除 DPPH自由基法,寻找抗氧化能力较强的组分,并利用半制备液相色谱对该组分进行分离、纯化,以清除 DPPH自由基、还原力和清除 ABTS自由基能力作为考察指标,根据理化性质及光谱数据鉴定化合物。结果从楸树叶粗提物的乙酸乙酯萃取相中分离得到了2个化合物,分别为木犀草素(1)和芹菜素(2)。化合物1的抗氧化活性强于BHT和化合物2;化合物1清除DPPH自由基、还原力及清除ABTS自由基的IC50值分别为23.89,29.77和43.47μg mL -1;化合物1的抗氧化活性强于化合物2,主要因其在黄酮类化合物母核的 B环上具有邻二酚羟基结构。木犀草素和芹菜素2个化合物首次从楸树叶中分离得到。 相似文献
9.
利用HPLC-UV研究了异海松酸(iPA) UV光固化反应产物,从中检测到了一种具有较强紫外吸收的非聚合物成分.通过硅胶柱色谱和制备型HPLC分离得到了该物质,经气相色谱分析检验,其纯度为82.6％.通过UV-vis、FT-IR、MS、1H NMR及13C NMR等光谱分析研究,该物质的化学结构被鉴定为7-羰基-8,15-异海松酸(7-O-8,15-iPA),这是异海松酸的一种氧化衍生物,与文献报道结构一致.还探讨了异海松酸发生氧化反应生成7-羰基-8,15-异海松酸的反应机理. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
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. 相似文献
12.
《Scandinavian Journal of Forest Research》2012,27(3):206-217
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. 相似文献
13.
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. 相似文献
14.
Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):118-130
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
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. 相似文献
18.
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。 相似文献
19.
Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
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. 相似文献
20.
《Wood material science & engineering》2013,8(2):76-84
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. 相似文献