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为探讨金镶玉竹(Phyllostachys aureosulcata 'Spectabilis’)在纬度水平上引种差异及其生理响应,以纬度依次相差3°的扬州(原产地)、聊城(引种地)、北京(引种地)3处金镶玉竹试验林为研究对象,测定叶片相对电导率,经Logistic 方程拟合获得3个纬度梯度下金镶玉竹的半致死温度(LT50),结合生理指标[超氧物歧化酶(SOD)活性、可溶性蛋白质、可溶性糖、丙二醛(MDA)和脯氨酸含量],通过隶属函数法进行抗寒能力的综合评价。结果表明：1)低温胁迫下金镶玉竹叶片MDA含量随温度的降低呈先上升后下降的趋势,相对电导率、可溶性糖、可溶性蛋白质、脯氨酸含量及SOD酶活性随温度的下降而升高;2)金镶玉竹LT50、可溶性糖、可溶性蛋白质、脯氨酸含量及SOD酶活性随着纬度的升高而降低,MDA含量变化与之相反;3)不同栽植地金镶玉竹的抗寒性综合排名为北京>聊城>扬州。研究结果显示,经过多年引种栽培,北京、聊城栽植的金镶玉竹抗寒性已显著高于扬州,高纬度地区引种栽植对金镶玉竹驯化效果显著。 相似文献
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《世界竹藤通讯》2015,(4)
通过对自然降温过程中曙箣竹各项生理指标和低温半致死温度的测定,研究了曙箣竹抗寒能力及相关生理特性的变化。结果表明:在自然降温过程中曙箣竹叶片的相对电导率、脯氨酸含量、可溶性蛋白含量均表现为先上升后下降再上升的趋势,温度为11℃时脯氨酸含量、可溶性蛋白含量出现峰值;随着温度的下降,丙二醛含量(MDA)含量呈先下降再上升趋势,20℃时MDA含量最高,仅8℃时与其他处理温度呈显著差异;超氧化物歧化酶(SOD)活性呈降低—升高—降低的变化趋势,SOD活性在8℃时达最大;过氧化物酶(POD)活性呈"W"型趋势变化,表现为降低—升高—降低—升高,POD活性除在20℃时最大并与5℃之间无显著差异外,与其他4个温度处理间均呈显著差异。以电导法配合Logistic方程测定曙竹叶片的半致死温度为-2.16℃,此温度可能是曙箣竹生理生化指标变化的节点,低于此温度叶片生理活动将受限。此外,曙箣竹主要通过渗透调节物质的变化来适应温度变化。 相似文献
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《中南林业科技大学学报(自然科学版)》2017,(10)
通过对土壤持续干旱及复水条件下迁西地区5个板栗品种(系)(ZJ、DBH、YL、YK、YSDZ)实生苗叶片的丙二醛、SOD、POD、可溶性糖和叶片水势进行测定,研究5个板栗品种(系)对干旱胁迫的生理响应,并进行抗旱性评价。结果表明:随干旱时间的延长,5个板栗品种(系)叶片的MDA含量呈增加趋势;5个板栗品种(系)叶片SOD活性呈降低-升高-降低的趋势,均在干旱胁迫30 d时达到最大值;YK叶片POD活性呈升高-降低-升高-降低的趋势,其余4个板栗品种(系)叶片POD活性呈升高-降低-升高的趋势。5个板栗品种(系)叶片POD活性均在干旱胁迫10 d时达到最大值;干旱胁迫10 d,ZJ叶片可溶性糖含量有所增加,其余4个板栗品种(系)均有所下降。之后,5个板栗品种(系)叶片可溶性糖含量均呈增加趋势;5个板栗品种(系)叶片水势均呈降低的趋势;复水14 d后,5个板栗品种(系)叶片MDA含量、可溶性糖含量均有所降低;各品种(系)板栗叶片SOD活性、水势较干旱胁迫40 d时有所升高;DBH叶片POD活性较干旱胁迫40 d时有所降低。其余4个板栗品种(系)叶片POD活性较干旱胁迫40 d时有所升高。经隶属函数法分析得出5个板栗品种(系)的抗旱性顺序为:DBH(0.57)ZJ(0.47)YL(0.43)YK(0.41)YSDZ(0.34)。 相似文献
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本文对低温胁迫下喜树幼苗叶片内超氧化物歧化酶（SOD）活性与叶绿素、游离脯氨酸、丙二醛（MDA）含量的变化进行了研究。结果表明：喜树幼苗经低温胁迫后叶内叶绿素含量下降；SOD活性先下降、后上升、再下降，其变化规律不同于其它植物；低温造成喜树幼苗的膜脂过氧化，MDA含量明显升高，SOD活性的增强可以降低MDA的含量；脯氨酸随着胁迫的进行其含量升高，表明叶内脯氨酸的升高也有助于提高它的抗寒性，进一步可以认为叶片内脯氨酸含量的高低可作为衡量喜树抗寒性指标。 相似文献
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于不同程度石漠化区的枫香、刺槐和柏木人工林中采集叶片为试材,通过比对3种植物叶片中叶绿素、SOD、丙二醛(MDA)和脯氨酸含量的变化,对石漠化区3种植物抗逆性进行分析评价。结果表明:不同石漠化程度区对植物体内SOD含量的影响显著。在轻度石漠化区,柏木SOD含量最高,刺槐SOD含量最低;在中度石漠化区,柏木SOD含量最高,枫香SOD含量最低;在重度石漠化区,枫香SOD含量最高,刺槐SOD含量最低。刺槐叶片MDA含量与叶绿素含量呈显著负相关,而柏木叶片MDA含量与叶绿素含量则呈显著正相关。 相似文献
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以华北连翘、美国金钟连翘、东北连翘和‘金叶连翘’4(品)种连翘属植物为试材,采用盆栽控水法使土壤含水量逐渐减少达到水分胁迫的要求,测定土壤含水量及其叶片可溶性糖含量、叶绿素含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性的变化,并进行综合分析.结果表明:随着土壤水分的降低,4(品)种连翘属植物叶片含水量和叶绿素含量呈下降趋势;东北连翘可溶性糖含量呈降低趋势,其他3(品)种为波动性上升;美国金钟连翘SOD活性呈波动下降趋势,其他3(品)种呈波动上升趋势,华北连翘和东北连翘POD活性波动下降,美国金钟连翘和‘金叶连翘’波动上升;4(品)种连翘属植物MDA均呈上升趋势.运用隶属函数法分析,4(品)种连翘的抗旱能力依次为‘金叶连翘’(0.53)＞华北连翘(0.48)＞东北连翘(0.41)＞美国金钟连翘(0.36). 相似文献
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自然降温过程中猴樟和香樟幼苗的抗寒性比较 总被引：2，自引：0，他引：2
以猴樟、香樟当年生幼苗为材料,研究10月至次年3月自然温度变化对猴樟和香樟幼叶中丙二醛(MDA)、超氧化物歧化酶(SOD)和脂肪酸含量的影响。结果表明,在自然降温过程中,2种樟树叶片中的MDA含量呈现先升高后降低的单峰曲线变化趋势,SOD呈现升-降-升-降的双峰曲线;脂肪酸组成成分主要有肉豆蔻酸、棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸;IUFA值(脂肪酸不饱和指数)变化趋势与亚麻酸含量及不饱和脂肪酸含量变化趋势相同,均呈先上升后下降趋势。其中猴樟的MDA含量、SOD活性及IUFA值高于香樟,综合各项指标,猴樟幼苗的抗寒性略强于香樟。 相似文献
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通过盆栽控水试验研究了不同水分胁迫条件下毛白杨(Populus tomentosa)8个1(2)-O型无性系苗木叶片中膜脂过氧化产物丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的动态变化过程.结果表明,随干旱胁迫强度的增大,毛白杨无性系叶片的MDA含量、CAT活性呈递增... 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