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1.
鱼鳞云杉干部显微解剖结构与云杉大黑天牛危害的关系   总被引:1,自引:0,他引:1  
鱼鳞云杉健康木和被害木干部解剖特征量中,存在显著性差异的指标包括胞壁厚(晚材)、管胞腔直径(径向早材)、管胞直径(早材)、木射线条数、管胞长(早材、晚材)、树脂道比量和木射线比量;逐步回归分析表明,管胞腔直径(径向早材)和管胞长(早材)为正相关,是有利于云杉大黑天牛危害的特征量,树脂道比量、木射线条数和木射线比量为负相关,是对云杉大黑天牛产生抗性的特征量。  相似文献   

2.
人工林马尾松木材性质的变异   总被引:7,自引:0,他引:7       下载免费PDF全文
本文研究了广西人工林马尾松木材性质的变异及幼龄材与成熟材的差异。结果表明 ,幼龄材与成熟材的分界年龄在 14  16a ,解剖性质在径向上的变异规律为 :射线比量、树脂道比量、胞壁率、胞腔直径、胞壁厚、管胞长度、管胞宽度和晚材壁腔比是自髓心向外呈递增趋势 ,管胞比量和晚材率为递减趋势 ,早材壁腔比和早材腔径比则近似于一条直线。方差分析结果表明 :树脂道比量、胞壁率、胞壁厚、管胞长度和管胞宽度 ,幼龄材与成熟材差异达显著或极显著水平。 5项木材物理力学性质均为成熟材高于幼龄材 ,且均达差异显著水平。木材性质间的相关分析表明 :木材基本密度与管胞长度、管胞宽度、射线比量、树脂道比量、胞壁率呈显著的正相关关系 ,木材气干密度与抗弯强度、抗弯弹性模量、顺纹抗压强度也呈显著的正相关关系  相似文献   

3.
云南松直干、弯干材木材结构比较观察   总被引:1,自引:0,他引:1  
利用光学显微镜对云南松直干、弯干材木材构造进行解剖学观察,结果表明:弯干材在解剖结构上跟直干材基本保持一致。与直干材相比,弯干材的早材比直干材的早材窄,树脂道多;早、晚材管胞的长度、壁厚、弦向直径差幅分别为:0.14、0.63、4.4、13.56、-0.46、0.81;最大交叉场纹孔数和最大单列射线细胞个数比直干材分别多1个和2个;纺锤形射线高度超出直干材的51.73%。弯干材具有右旋扭转纹。另外,两种材料都是较好的造纸原料,且以弯干材为优。  相似文献   

4.
黄花落叶松木材超微结构及其对渗透性的影响   总被引:1,自引:3,他引:1  
本文详细地介绍了黄花落叶松木材超微结构特征及其对木材渗透性的影响,心材和边材管胞具缘纹孔的超微结构及其在不同部位和不同处理方法中的变化;晚材管胞具缘纹孔超微结构的变化;细胞壁各层次中的微纤丝及其周围的基质和结壳物质等的渗入或沉积性状。同时还针对黄花落叶松木材渗透性差,及一些晚材具缘纹孔少闭塞或不闭塞的原因,从木材的超微结构特点进行了较详细的探讨。  相似文献   

5.
借助光学显微镜和计算机显微图像分析系统,对矮生杉木的解剖性质进行了研究,其主要特征:①矮生杉木生长轮明显,早晚材缓变;管胞壁上的具缘纹孔单列;轴向薄壁组织量多,星散状排列;木射线高有3~12个细胞,多数为3~7个细胞;射线薄壁细胞与早材管胞间的交叉场为杉木型,多2~4个.②矮生杉木第2年轮单位面积的管胞数量平均值为4 047个/mm2,径向层数平均值为118层/轮.③矮生杉木管胞长度平均值为1 560.5μm,管胞宽度平均值为20.06μm,管胞双壁厚平均值为3.602μm,管胞壁腔比平均值为0.21,管胞长宽比平均值为69.90,腔径比平均值为0.830.  相似文献   

6.
为给杏(Armeniaca vulgaris)木的合理利用提供理论支持,利用生物数码显微镜对杏木的宏观和微观特征进行观察与分析。结果表明,杏木边材为黄红色至黄褐色,心材为红褐色和灰褐至带红的浅黄褐色;心、边材区别明显。环孔材;早材管孔宽1~3(稀4)列;晚材管孔为单管孔及径列复管孔(2~3个),少数呈管孔团,散生或斜列;单穿孔,穿孔板倾斜;管间纹孔式互列;未见侵填体;早材和晚材管孔螺纹加厚明显。木纤维壁薄,具缘纹孔较多。木射线非叠生,射线组织异形Ⅱ型,少数为Ⅲ型;单列射线高1~18个细胞或以上;多列射线宽2~8个(多数为2~6个)细胞,高8~64个细胞或以上。生长轮外缘具创伤树胶道。杏虽为进化树种,但保留了部分原始形状特点,说明杏的进化是不同步的。杏木的结构与生长环境相适应。  相似文献   

7.
本文以河南省经济林胡桃树枝为研究对象,采用数字成像系统对解剖特征拍照,使用木材显微构造测量系统测量其木射线组织物理形态及指标,并分析了不同树枝直径和树枝级别木射线物理形态的差异。结果表明:胡桃枝材木射线类型为单列木射线和多列木射线。射线细胞类型有同型单列、同型多列、异型单列、异型Ⅲ型。木射线高度、宽度平均值分别99.54μm、14.20μm,射线细胞长度、高度、壁厚平均值分别为25.72μm、9.07μm、1.70μm。胡桃枝材的木射线各指标在树枝级别间均差异显著,其中三级枝的枝材整体木射线尺寸最小。树枝直径与胡桃枝材射线细胞长度、射线细胞壁厚、木射线宽度呈正相关,与射线细胞高度呈负相关。  相似文献   

8.
两种难浸注木材的显微和超微构造及其与渗透性的关系   总被引:2,自引:2,他引:0  
姜笑梅  鲍甫成 《林业科学》1993,29(4):331-337,T001,2,3
详细介绍了长白鱼鳞云杉、臭冷杉木材的显微和超微构造特征及其对木材渗透性影响,两树种的心材管胞具缘纹孔膜和管胞胞壁各层纤丝中丰富的无定形物质的沉积是心材渗透性差的解剖方面的主要原因。  相似文献   

9.
马尾松木材超微结构及其结晶体的研究   总被引:1,自引:0,他引:1  
本文系统地介绍了马尾松木材超微结构,包括:具缘纹孔,胞壁不同层次微纤丝的排列方向,瘤状层,并首次在松树木材的纹孔室内、管胞胞腔和木射线细胞中看到有钙晶体。经进一步研究表明,是类晶体系真菌新陈代谢的结果,菌丝束穿入至上述部位,并有晶体发现。因此切勿将此类晶体视为一种正常构造。作者还分别对心边材、早晚材带的纹孔结构的差别进行观察研究,并进一步提供了纹孔托初生构造的证据和边材较心材、晚材较早材易于渗透等的证据。S_2层表面还看到一些任意排列的微纤丝,可能是S_2层和S_3层的交接层或S_3层外表面的部分性状。瘤状层用0.25%次氯酸钠处理后瘤状层有减小、减少,有的甚至不易见的趋势。  相似文献   

10.
该文以毛株的树根、树干和树枝次生木质部为研究对象,采用石蜡切片法对其解剖学特性进行研究,结果表明:毛株是散孔材,单管孔和复管孔并存,呈径列星散状分布,射线类型为异型射线;薄壁组织傍管型和离管型均有;树干和树枝导管具梯状穿孔板,管壁有具缘纹孔,多呈纺锤形;树根导管多呈圆柱形或鼓形,单穿孔,部分导管含有侵填体.毛株解剖结构...  相似文献   

11.
Summary The cross-sectional view of pitting between various cell types inPinus banksiana Lamb. was studied at the ultrastructural level. Cell types inPinus banksiana include longitudinal tracheids, ray tracheids, ray parenchyma cells, buffer cells and epithelial cells. Two common characteristic features of bordered pit-pairs between longitudinal tracheids are an initial pit border and a thickened torus at the center of the pit membrane. The shape and size of the pit border and torus of bordered pit-pairs between two compression wood cells, and between the last-formed latewood longitudinal tracheid and first-formed earlywood longitudinal tracheid were different from those in the earlywood and latewood longitudinal tracheids. The pit border on the ray tracheid side varied in size and shape due to wall dentation. No initial pit border was found on the pit border of the ray tracheid side. The shape of bordered pit-pairs between two ray tracheids varied considerably due to irregularity of the dentate cell wall. The size of bordered pit-pairs in longitudinal tracheids was between 16 m to 20 m, which was twice the diameter of bordered pit-pairs in ray tracheids. Bordered pitpairs at the end wall of two ray tracheids appeared to be the smallest at 5 m, Pit aspiration occurred in the bordered pit-pairs with or without a torus. In the heartwood zone, some half-borders pit-pairs between tracheary and ray parenchyma cells showed an additional secondary wall on the ray parenchyma cell side. Plasmodesmata were found in the half-bordered pit-pairs as well in the simple pit-pairs. Blind pits were observed between a ray tracheid and a longitudinal tracheid. Bordered pit-pairs between two buffer cells were also observed. The possible functions of buffer cells were discussed.Use of transmission electron microscope provided by the Science Instrumentation Lab, Lakehead University and the technical assistance provided by Mr. A. MacKenzie, Director of Science Instrumentation Lab are gratefully appreciated  相似文献   

12.
Stem segments of eight five-year-old Norway spruce (Picea abies (L.) Karst.) clones differing in growth characteristics were tested for maximum specific hydraulic conductivity (k(s100)), vulnerability to cavitation and behavior under mechanical stress. The vulnerability of the clones to cavitation was assessed by measuring the applied air pressure required to cause 12 and 50% loss of conductivity (Psi(12), Psi(50)) and the percent loss of conductivity at 4 MPa applied air pressure (PLC(4MPa)). The bending strength and stiffness and the axial compression strength and stiffness of the same stem segments were measured to characterize wood mechanical properties. Growth ring width, wood density, latewood percentage, lumen diameter, cell wall thickness, tracheid length and pit dimensions of earlywood cells, spiral grain and microfibril angles were examined to identify structure-function relationships. High k(s100) was strongly and positively related to spiral grain angle, which corresponded positively to tracheid length and pit dimensions. Spiral grain may reduce flow resistance of the bordered pits of the first earlywood tracheids, which are characterized by rounded tips and an equal distribution of pits along the entire length. Wood density was unrelated to hydraulic vulnerability parameters. Traits associated with higher hydraulic vulnerability were long tracheids, high latewood percentage and thick earlywood cell walls. The positive relationship between earlywood cell wall thickness and vulnerability to cavitation suggest that air seeding through the margo of bordered pits may occur in earlywood. There was a positive phenotypic and genotypic relationship between k(s100) and PLC(4MPa), and both parameters were positively related to tree growth rate. Variability in mechanical properties depended mostly on wood density, but also on the amount of compression wood. Accordingly, hydraulic conductivity and mechanical strength or stiffness showed no tradeoff.  相似文献   

13.
The pattern and extent of variation of microfibril angle (MFA) in normal and compression tracheids of softwood were investigated by using confocal laser scanning microscopy technique. All measurements support the idea that the orientation of microfibrils in single wood tracheids is not uniform. MFA of the radial wall of earlywood tracheids was highly non-uniform and had an approximately circular form of arrangement around the bordered pits (inside the border). Between the bordered pits the measured MFAs were less than the other parts of the tracheid. In the latewood tracheids MFA was less variable. The average orientation of simple pits in the crossfield region was consistent with the mean MFA of the tracheids; however some of the measurements showed a highly variable arrangement in the areas between the simple pits. In many cases the local measured MFAs of compression wood tracheids agreed with the orientation of natural helical cavities of compression wood. Comparing the measured results in different growth rings showed that MFAs in juvenile wood are generally larger than in perfect wood.  相似文献   

14.
We studied the effects of elevated temperature and carbon dioxide concentration ([CO(2)]) alone and together on wood anatomy of 20-year-old Scots pine (Pinus sylvestris L.) trees. The study was conducted in 16 closed chambers, providing a factorial combination of two temperature regimes and two CO(2) concentrations (ambient and elevated), with four trees in each treatment. The climate scenario included a doubling of [CO(2)] and a corresponding increase of 2-6 degrees C in temperature at the site depending on the season. Anatomical characteristics analyzed were annual earlywood, latewood and ring widths, intra-ring wood densities (earlywood, latewood and mean wood density), tracheid width, length, wall thickness, lumen diameter, wall thickness:lumen diameter ratio and mass per unit length (coarseness), and numbers of rays, resin canals and tracheids per xylem cross-sectional area. Elevated [CO(2)] increased ring width in four of six treatment years; earlywood width increased in the first two years and latewood width in the third year. Tracheid walls in both the earlywood and latewood tended to become thicker over the 6-year treatment period when temperature or [CO(2)] was elevated alone, whereas in the combined treatment they tended to become thinner relative to the tracheids of trees grown under ambient conditions. Latewood tracheid lumen diameters were larger in all the treatments relative to ambient conditions over the 6-year period, whereas lumen diameters in earlywood increased only in response to elevated [CO(2)] and were 3-6% smaller in the treatments with elevated temperature than in ambient conditions. Tracheid width, length and coarseness were greater in trees grown in elevated than in ambient temperature. The number of resin canals per mm(2) decreased in the elevated [CO(2)] treatment and increased in the elevated temperature treatments relative to ambient conditions. The treatments decreased the number of rays and tracheids per mm(2) of cross-sectional area, the greatest decrease occurring in the elevated [CO(2)] treatment. It seemed that xylem anatomy was affected more by elevated temperature than by elevated [CO(2)] and that the effects of temperature were confined to the earlywood.  相似文献   

15.
The technology of steam explosion was applied to pre-treat sub-alpine fir (Abies lasiocarpa (Hook.) Nutt.) lumber and to improve its drying characteristics. Effects of steam explosion on the appearance and structure of the lumber are discussed in this paper. The structure of the wood was examined using light microscope (LM) and scanning electron microscope (SEM). The following results were obtained. With increasing temperature, pressure, and explosion cycles the color of the lumber darkened gradually. No significant structural difference between treated and untreated samples was observed using LM when the treatments were carried out at temperatures below 130°C with ten explosion cycles (group A or B). Some fractures were observed in bordered pit pairs between tracheids after 20 explosion cycles at 130°C (group C). More fractures occurred in bordered pit pairs between earlywood tracheids at a temperature of 160°C (group D). More or less fractures in pits between ray parenchyma cells and earlywood tracheids were observed using SEM in all four cases of treatments. Although no change in bordered pits in the tracheid walls between group A and the control group was discovered, groups B, C, and D showed different extents of ruptures in bordered pits, which may lead to break aspirated pits and improve permeability. In these groups, wrinkles and separations in the inner tracheid walls and detachments in middle lamella also occurred and became more serious as temperature or cycles of the treatment increased.  相似文献   

16.
Aumann CA  Ford ED 《Tree physiology》2006,26(3):285-301
A tracheid-level model was used to quantify the effects of differences in wood microstructure between coastal and interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii and var. glauca) wood on larger scale properties like hydraulic conductivity. The model showed that tracheid length, the ease of flow through a bordered pit and effective tracheid diameter can all limit maximum hydraulic conductivity. Among the model parameters tested, increasing bordered pit conductivity and tracheid length resulted in the greatest increase in maximum conductivity in both the inland and coastal ecotypes. A sensitivity analysis of the uncertainty between parameters governing flow through the bordered pit and air-seeding potential showed that, although decreased pit flow resistance increased maximum hydraulic conductivity, increased cavitation led to lower conductivity over time. The benefits of increasing the number of bordered pits depended on the intensity of the meteorological driving function: in drier environmental conditions, wood with fewer pits was more conductive over time than wood with more pits. Switching the bordered pit characteristics between coastal and interior wood indicated that the conductivity time course of coastal and interior wood was primarily governed by differences in the number of bordered pits and not differences in tracheid dimensions. The rate at which tracheids refilled had little effect on the conductivity time course of either coastal or interior wood during the first two summers when the wood was highly saturated, but had a marked influence in subsequent years once the cavitation profile stabilized. Our work highlights the need for more empirical work on bordered pits to determine whether variation in their number and properties is related to changing environmental conditions. In addition, a detailed simulation model of a bordered pit is needed to understand how variation in pit properties affects the relationship between ease of flow through a bordered pit and its potential for facilitating air-seeding.  相似文献   

17.
日本落叶松无性系木材性质的遗传变异   总被引:6,自引:3,他引:3       下载免费PDF全文
对10个10年生日本落叶松无性系的木材基本密度、管胞参数进行了测定.结果表明:木材基本密度,早、晚材管胞宽度和早材长宽比无性系间差异显著;木材基本密度,早、晚材管胞长度,早晚材管胞宽度和早晚材长宽比径向变异模式相似,即从髓心向外以曲线形式不断增加,有时亦有起伏;早材从髓心向外以近似直线的形式缓慢增加,晚材从髓心向外以曲线形式增加,初期增加幅度较大,到一定年龄后趋于水平变化并略有波动;材质性状与树木年轮间的关系以对数方程、幂函数方程、指数方程拟合效果较好;除了晚材壁腔比和早材壁厚外,其它木材性质的重复力均在0.5以上,受中度或中度以上的遗传制约,按照20%的选择率,长宽比和晚材管胞长能获得较高的遗传增益.  相似文献   

18.
Treatability of wood is a function of anatomical properties developed under certain growing conditions. While Scots pine sapwood material normally is considered as easy to impregnate, great variations in treatability can be observed. In order to study anatomical differences in the structural elements of transverse fluid passage, wood material with contrasting treatability has been compared. Ray composition and resin canal network, membrane areas of fenestriform pits in the cross-field as well as dimension and properties of bordered pits were investigated. The results showed large anatomical differences between the two contrasting treatability groups. Refractory Scots pine sapwood samples developed more rays per mm2 tangential section, while they were on average lower in cell numbers than rays found in easily treatable material. Easily treatable material had more parenchyma cells in rays than refractory material. At the same time, a larger membrane area in fenestriform pits in the cross-field was observed in the easily treatable sample fraction. Differences in the composition of resin canal network were not observed. Refractory samples developed on average smaller bordered pit features, with relatively small formed pit apertures compared to the easily treatable samples. In refractory Scots pine sapwood material, the structural elements of fluid passage such as bordered pit dimensions, fenestriform pits in the cross-field and parenchyma cells were altogether developed in smaller dimensions or number. Wood samples from better growing conditions and sufficient water supply showed a better treatability in this study.  相似文献   

19.
We investigated morphological changes in wood tissues of sugi (Cryptomeria japonica) resulting from treatment with the ionic liquid 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), which dissolves cellulose. Treatment with [C2mim][Cl] caused dissociation and distortion of tracheids in latewood, but not in earlywood. This difference was due to the difference in swelling behavior of the cell wall between earlywood and latewood. Many pit membranes in bordered pits were broken by treatment with [C2mim][Cl]. In addition, some chemical changes in wood components, such as cellulose and lignin, occurred before significant disruption or destruction of the cell wall. Our results show that the reaction of wood liquefaction by [C2mim][Cl] treatment is not homogeneous, both from chemical and morphological viewpoints.  相似文献   

20.
落叶松种间及其杂种管胞特征及微纤丝角的变异   总被引:4,自引:1,他引:3       下载免费PDF全文
对落叶松属4个种及其以日本落叶松为母本的种间杂交组合的早晚材管胞形态和微纤丝角进行了测定分析,研究结果表明:落叶松各管胞特征值及微纤丝角基本符合甚至远超过较优纸浆材筛选要求;落叶松种间及其杂种早晚材管胞形态特征值差异显著或极显著,早、晚材管胞长变幅分别为3164.45~3 865.26、3 318.51~4 200.8...  相似文献   

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