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以红花石蒜叶片基因组DNA为模板,分析了模板DNA、引物、dNTPs、Mg2 的浓度及Taq DNA聚合酶的用量对ISSR-PCR扩增结果的影响.建立了石蒜ISSR分析最优化的反应体系及应用程序:即25 μL反应体系中,有20 ng模板DNA、0.5 μmol·L-1随机引物、150 μmol·L-1 dNTPs、2.0 mmol·L-1 Mg2 、1.0 U Taq DNA聚合酶.反应程序为:94 ℃预变性5 min;然后45个循环:每个循环94 ℃变性45 s,55 ℃退火60 s,72 ℃延伸2 min;循环结束后72 ℃延伸7 min. 相似文献
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利用正交试验L16(45),结合单因素试验对厚朴相关序列扩增多态性(Sequence-related amplified polymorphism,SRAP)标记反应体系的5个因素(Mg2+,dNTPs,引物,Taq酶和模板DNA)进行优化试验,结果表明:各因素水平变化对PCR反应的影响从大到小依次为:dNTPsTaq酶模板DNAMg2+引物;筛选出各反应因素的最佳水平,建立厚朴SRAP-PCR反应的最佳体系(25μL)为:Taq酶1.5 U,Mg2+1.8 mmol.L-1,模板DNA100 ng,dNTP 0.24 mmol.L-1,引物0.40μL。试验表明,该体系重复性好、稳定性强。 相似文献
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以漾濞核桃中的大姚三台核桃为实验材料,通过对影响RAPD扩增结果的主要因子Tag酶、Mg+2、引物、模板DNA、dNTPs等不同的浓度和组合的试验研究,确定了漾濞核桃的最适反应体系和扩增程序,即在25μL反应体系中,0.75 u.L-1Taq DNA聚合酶,3.0 mmol.L-1Mg+2,0.3 mmol.L-1引物,含1.6 mg.L-1模板,2.5 ul 10×Buffer,dNTPs各0.2 mmol.L-1。扩增程序为:94℃预变性300 s,94℃变性40 s,36℃退火60 s,72℃链延伸120 s,45次循环后,72℃延伸600 s。 相似文献
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用正交设计法优化枣树ISSR-PCR反应体系 总被引：5，自引：0，他引：5
采用正交设计的方法对枣ISSR-PCR反应体系的5因素(Taq酶、Mg2+、模板DNA、dNTPs、引物的浓度)在4水平上进行优化试验,PCR结果用DPS数据处理软件分析。实验结果表明:各因素的不同水平对PCR反应结果都有显著的影响,其中Mg2+影响最大;筛选出了各反应因素的最佳水平,建立枣ISSR-PCR的最佳反应体系(25μL)为:Taq酶1.0 U、Mg2+1.0 mmol/L模板DNA 1.0μL、dNTPs 0.25 mmol/L、引物0.3μmol/L。 相似文献
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硅胶干燥野扁桃叶片制备DNA样品及其SSR反应体系的建立 总被引：3，自引：0，他引：3
对硅胶干燥保存制备新疆野扁桃DNA样品和SSR反应体系优化进行了研究.结果表明:在室温下贮存3个月、6个月、9个月、1年和2年的硅胶干燥的同一野扁桃叶片材料中采用改进的CTAB法提取了高质量的基因组总DNA.较好的克服了野扁桃叶片中含有较高的多糖、多酚、色素以及单宁等次生物质的影响.通过A2s0/A280,琼脂糖凝胶电泳和PCR-SSR扩增结果分析对提取的基因组DNA进行了鉴定,2年内不同保存时期的同一材料对于DNA提取没有明显差异,提取的DNA用于SSR扩增所得的扩增产物也均无明显差异;确立野扁桃最佳的PCR-SSR反应体系是30～50 ng DNA模板,0.5UTaqDNA聚合酶,2.0mmol·L-1MgCl2,0.2 mmol·L-1dNTPs,0.2 mmol·L-1的引物,10×Taq酶配套缓冲液(pH 8.0),反应终体积20uL,引物最佳退火温度为54～57C.利用40个野扁桃随机叶样验证此反应体系,变性聚丙烯酰胺凝胶电泳检测结果显示,扩增产物在200～600 bp,多态性高,且反应体系的稳定性和可重复性好. 相似文献
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鹅掌楸ISSR-PCR反应体系的建立及优化 总被引：2，自引：0，他引：2
为建立鹅掌楸简单序列重复区间扩增ISSR的PCR优化反应体系,以鹅掌楸叶片基因组DNA为材料,系统地测试了模板DNA、引物、dNTPs、Mg2+浓度、TaqDNA聚合酶用量及退火温度对ISSR-PCR反应体系的影响。结果表明:优化的PCR反应体系为:20μL总体系中,含30 ng模板DNA,0.3μmol.L-1随机引物,0.2 mmol.L-1dNTPs,1.4 mmol.L-1Mg2+,0.8 UTaqDNA聚合酶;最佳退火温度为60℃;PCR反应程序为:94℃预变性5 min;94℃变性1 min,60℃退火45 s,72℃延伸2 min;45个循环;72℃再延伸7 min。 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
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《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
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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
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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
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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
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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
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《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