共查询到20条相似文献，搜索用时 781 毫秒
1.
风信子组培快繁技术的研究 总被引：5，自引：0，他引：5
采用不同诱导、继代和生根培养基进行风信子组培快繁技术研究，结果表明：鳞片不定芽诱导的最佳培养基为MS 6-BA1．0—1．5mg／L NAA0．2—0．4mg／L；不定芽继代培养的最佳培养基为MS 6-BA1．0mg／L NAA0．2mg／L；最佳生根培养基为1／2MS NAA0．3mg／L；蛭石1份 珍珠岩1份 园土1份是风信子试管苗最佳的驯化移栽基质，在该基质中生根苗移栽成活率达90％。 相似文献
2.
丽格海棠叶片的组织培养研究 总被引：1，自引：0，他引：1
取丽格海棠叶片作外植体,通过试验,分析不同激素配比对芽的诱导、增殖及生根的影响,筛选出丽格海棠叶片组织培养的适宜培养基及试管苗最佳移栽基质。结果表明：其最佳诱导培养基为MS＋6-BA1．5mg／L＋NAA0．8mg／L,不定芽诱导率达100％;最佳继代培养基是MS＋6-BA1．0mg／L＋NAA0．5mg／L,增殖倍数达6．5倍;最佳生根培养基是1／2MS＋NAA0．4mg／L,生根率达100％;试管苗最佳移栽基质为用1／2MS大量元素浇透的草炭,移栽成活率为85％。 相似文献
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大莺歌凤梨的离体培养快速繁殖试验 总被引：5，自引：0，他引：5
大莺歌凤梨组培快繁研究的结果表明：以茎尖或腋芽茎段为外植体,在培养基MS(或1／2MS) NAA1mg／L(或2,4-D2mg／L) 6-BA1～5mg／L上均可诱导芽分化,其中以1／2MS NAAlmg／L 6-BA5mg／L效果最好,培养43d可诱导出芽,分化频率50％;在培养基1／2MS NAA0．5mg／L 6-BA1mg／L上继代培养的增殖速率最高,培养30d芽的平均增殖倍数为7．4倍,降低6-BA浓度或提高NAA浓度有利于培养壮苗;1／2MS IBA1．0mg／L 1g／L活性炭的培养基诱导植株生根效果最好,30d生根率100％,平均每株苗生根3．5条,平均根长1.8cm;生根试管苗移栽于泥炭土：珍珠岩=1：1的基质,成活率约70％。软腐病是影响移栽成活率的主要因素,通风和对基质进行消毒可减少软腐病的发生。 相似文献
6.
本试验采用无菌落雪泥为材料,分别对试管苗诱导、增殖和生根条件进行了初步研究。结果表明：诱导叶片分化的最佳培养基为：MS＋6-BA2．0mg／L＋NAA0．2mg／L;最适的增殖培养基是MS＋6-BA2．0mg／L＋NAA0．1mg／L;生根的培养基：1／2MS＋IBA0．4mg／L。在自动控制温室中,落雪泥始终处于高湿度、恒温环境中,草炭土是最适宜移栽的基质。在简易大棚中,落雪泥生活在湿度、温度不恒定的环境中,珍珠岩是最适宜移栽的基质,生根苗有100％的成活率。本试验为农民产业化生产落雪泥提供了理论依据和技术支持。 相似文献
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4个芦荟品种离体快繁技术研究 总被引：1，自引：0，他引：1
该文对库拉索、中华、木立和高尚4个芦荟品种离体快繁技术进行了研究。结果表明，库拉索和木立芦荟不定芽间接分化，库拉索主要是丛生芽＋愈伤组织方式，木立芦荟主要是愈伤组织的形式；中华芦荟和高尚芦荟主要是丛生芽方式直接分化。4个芦荟品种的最适继代增殖培养基库拉索为MS＋6-BA2．0mg／L＋NAA0．1mg／L，繁殖系数为7．29；中华芦荟为MS＋6-BA1．0mg／L＋NAA1．5mg／L，繁殖系数达6．64；木立芦荟为MS＋6-BA2．0mg／L＋NAA0．1mg／L，繁殖系数达14．0；高尚芦荟为MS＋6-BA1．0mg／L＋NAA0．1mg／L，繁殖系数达8．10。库拉索和中华芦荟的最适生根培养基为MS＋NAA0．5mg／L，生根率分别为86．5％和100％；木立和高尚芦荟为MS，生根率分别为99％和79％。最适移栽基质为珍珠岩：河沙：草炭土=1：1：1，成活率达92％。 相似文献
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麝香百合的组织培养与快速繁殖 总被引：7，自引：0，他引：7
利用麝香百合茎段，采用水培法形成的珠芽作为外植体进行组织培养。试验结果表明，最佳诱导分化培养基为MS BAl．0mg／L NAA0．4mg／L，继代增殖培养基为MS BA2．0mg／L NAA0．1mg／L，生根培养基为1／2MS mA0．3～0．4mg／L，生根率达98％～99％，最佳移栽基质为蛭石：细砂：油渣(140：59：1)，成活率达96％。 相似文献
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红叶石楠组织培养快速繁殖技术研究 总被引：3，自引：0，他引：3
红叶石楠是一种优良的彩色观叶园林植物，采用植物组织培养方法对其快速繁殖技术进行研究。结果显示：外植体诱导培养基采用MS＋6-BA0．5mg／L＋IBA0．1mg／L，不定芽的诱导率达76％；增殖培养基采用MS＋6-BA2.0mg/L＋KT0.5mg／L＋IBA0．2mg／L，丛生芽增殖率达6．32倍；生根培养基为1／2MS＋NAA0．5mg／L＋CCO0．5mg／L，生根率达100％。 相似文献
11.
《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
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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
15.
《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
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