共查询到18条相似文献，搜索用时 156 毫秒
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运用细胞图象分析系统及显微照相的方法对柚木次生木质部导管分子进行了观察研究.在柚木的次生木质部导管分子中存在着许多不同的样式,分别对其进行了描述,并从导管分子个体发育与系统发育的角度进行了讨论. 相似文献
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海桑属(Sonneratia)6种红树植物的木材解剖特性及其应用 总被引：8，自引：0，他引：8
应用光镜及扫描电镜对生长在热带、亚热带海岸潮间带的 6种海桑属红树植物的次生木质部进行了解剖学研究表明 :海桑属 6种红树植物的次生木质部具有导管直径小 ,导管分布频率高 ,复孔率高 ,导管壁厚和纤维壁较厚且具次生加厚 ,木薄壁组织缺乏或稀少等与环境相适应的特点。海桑属 6种红树植物的数量特征还表明 :海桑、无瓣海桑、卵叶海桑的木材可能适合造纸。 相似文献
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土壤盐胁迫下杨树次生木质部的解剖特征 总被引：2，自引：0，他引：2
对生长在苏北沿海防护林不同土壤盐度下的主栽树种杨树(欧美杨无性系69杨)进行了解剖,描述了杨树次生木质部结构的特征,测量了次生木质部的16个数量特征：年轮宽度(ARW)、导管长度(VL)、早材和晚材的导管分子面积(VA)、导管周长(VP)、导管直径(VD)、导管单孔率(PSV)、导管频率(VF)、纤维长度(FL)、纤维宽度(FW)、射线高度(RH)和射线频率(RF)。实验结果表明,在不同的土壤盐度胁迫下：(1)杨树次生木质部形态特征的差别不明显,但是组成分子趋向于小型化。(2)次生木质部数量特征的变化比较明显,即当土壤含盐量从0．036％逐渐升高到0．289％,杨树的年轮宽度变小,0．91→0．77mm;纤维长度和宽度的变化分别为693．8→570μm和14．9→13．5μm,射线高度和频率的变化分别为284．3→249．2μm和58．9→75．5mm^-2,表明在盐胁迫下杨树的生长受到抑制。随着盐度的增加0．036％→0．289％,杨树导管长度减小,367．6→341．5μm;在早材和晚材中,导管面积变化分别为1575．6→1703．6μm^2和760．1→947．7μm^2,导管周长变化分别为167．7→195．1μm和120．8→143．7μm,导管直径的变化分别为41．8→43．4μm和29．1→33．1μm,导管频率的变化分别为141．8→144．2mm^-2和160→206．7mm^-2;导管单孔率的变化分别为65．9％→30．5％和59．4％→40．8％。这些都表明在盐胁迫下杨树的导管缩短变粗,呈聚集分布,输水效率和输水安全性都有所提高。 相似文献
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对1年生毛白杨人工接种后,毛白杨与瘿瘤木纤维和导管分子长、宽、腔径、长宽比、壁厚与化学组成变异进行测定与分析.结果表明:纤维各解剖参数(壁厚除外)在处理组接种处明显下降,上方木质部和接种处导管变小,下方受其影响较小.方差分析表明:处理组毛白杨木质部木纤维及导管分子差异极显著;对照组木质部木纤维和导管分子无明显变化;瘿瘤之间木纤维及导管分子的长、宽均差异显著,说明瘿瘤细胞分裂异常;与木质部相比,瘿瘤中木纤维和导管分子明显减小;毛白杨木质部和瘿瘤之间木纤维及导管分子差异达显著和极显著.处理组毛白杨接种处冷水抽出物、热水抽出物、1%NaOH抽出物含量增加,纤维素含量降低,木质素含量最高.方差分析表明:处理组毛白杨化学组成变异极显著,对照组毛白杨各接种部位和瘿瘤之间化学组成均变化平稳.瘿瘤木质部中冷水抽出物、热水抽出物、1%NaOH抽出物含量分别比提高了2.6～4.3,1.5～2.6,1.1～1.8倍,而纤维素含量下降了51%～99%,处理组毛白杨接种处木质素含量是瘿瘤的2.7倍,和其他接种部位相比,瘿瘤木质素含量略高. 相似文献
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枣树不同枝类次生木质部细胞解剖学研究初探 总被引：2，自引：0，他引：2
试验以骏枣、梨枣为试材，富士苹果为对照，对各供试品种不同枝类次生木质部细胞进行解离。在光学显微镜下观察分析。结果表明：骏枣、梨枣和苹果的导管细胞均为孔纹导管类型；枣的导管细胞有较厚的侧壁加厚，特别是枣股导管细胞次生壁不仅加厚明显，且细胞纹孔很小；枣与苹果之间，导管和纤维细胞的长度和直径表现极显著的差异。同一枣品种中，不同枝条及不同年龄枝条之间也表现显著的和极显著的差异；枣股的畸形细胞所占比例最多。 相似文献
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竹节解剖构造的研究 总被引：17，自引：0，他引：17
对6种竹子节的解剖构造进行了观察,并将节部的构造与节间的构造进行比较。在节部,维管束大量分叉,形成复杂的网络系统。象竹秆节间中那样的典型的维管束结构消失了。维管束的侧鞘通常发育很差或不发育;丛生竹维管束两极的分离纤维束不复存在。原生木质部的侵填体不仅发生在散生竹类,而且也发生在丛生竹类。后生木质部已不再有2个大型的导管组成,而由大量的大小不等的导管组成。为了适应水分及养分的横向转运,原生木质部的导管常具分叉,后生木质部的导管则具多个穿孔;韧皮部筛管分子的侧壁上分布了大量筛域,在韧皮部分叉处,大量细长的线形韧皮薄壁细胞形成纺锤体状的迭生构造。基本组织细胞的形态极不规则。纤维的平均长度要较节间内的短得多,其尾端通常圆钝,有时具长的分叉,部分纤维细胞内有内含物。通过连续切片的观察,重建了维管束在节部的分布模式。 相似文献
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为了研究不同提取方法对黄皮叶片蛋白质提取质量的影响,以‘杨妃山黄皮’的叶片为材料,采用TrisHCl法、三氯乙酸(TCA)/丙酮法、尿素(Thi)/硫脲(Urea)法、酚(Phe)-甲醇/醋酸铵沉淀法提取叶片组织蛋白质,对获得的蛋白质产量、单向电泳图谱和双向电泳图谱分析比较。结果显示,不同方法的提取效果各异,就提取的蛋白质产率、单向电泳以及双向电泳结果来说,三氯乙酸(TCA)/丙酮法提取效果较理想,单双向电泳图谱辨识度强,蛋白点数多、蛋白点整洁、且纵横纹少。说明该法不但可以较好地去除黄皮叶片中存在的非蛋白物质,而且可以获取高质量的蛋白质。 相似文献
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The antibacterial activity of different crude extracts of Clausena heptaphylla leaves as well as three purified coumarins, obtained from the cold methanol extract, is reported. 相似文献
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The ethanolic extract of Clausena excavata leaves, given orally at doses of 125.25 and 500 mg/kg body weight, showed significant antinociceptive activity on acetic acid induced writhing in mice. 相似文献
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从生态学角度对沙棘和沙枣的木材结构进行对比研究.两树种具有的共同特点为 :生长轮明显,半环孔材,具单穿孔,导管间纹孔交互排列,无分隔木纤维,导管较窄, 环管管胞和纤维状管胞具螺纹加厚,轴向薄壁组织缺失或很少.所选树种明显区别是射线类型、宽度和叠生排列方式:沙棘射线,轴向薄壁组织细胞和导管分子具有明显的叠生排列方式,但沙枣的叠生排列不规则;沙棘射线为异型,1～2列,沙枣射线为同型,2～5列;并且二者之间数量化指标有差异,沙棘导管频率较大,导管分子较短及导管管孔较小,因此V和M值也较小,更能适应干旱环境.两树种导管分子长和纤维长的水平变动不规律,并且树种间和同一树种个体间差异显著.本文最后对该树种的解剖学特征和沙漠环境的适应性进行了讨论 . 相似文献
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Field-grown poplar trees (Populus nigra L. x P. maximowiczii Henry, clone Kamabuchi) were exposed to severe drought twice during the growing season to evaluate the impact on wood cell development. The drought treatment caused a reduction in leaf water potential, leaf wilting and a decreased concentration of osmotically active solutes in the cambial zone. Drought-induced changes in the anatomy of developing xylem cells were examined in stem sections and macerated wood samples. In early summer, drought significantly reduced the length and cross-sectional area of newly formed fibers, whereas no such effects were observed in late summer. In well-watered trees, fiber cross-sectional area declined between early and late summer. Similarly, drought reduced the cross-sectional area of vessel elements in early summer but not in late summer, whereas in both control and drought-treated trees, the cross-sectional area of vessel elements decreased between early and late summer. The vessel area to xylem area ratio was unaffected by drought because the drought-induced decrease in vessel size was matched by an increase in the number of newly formed vessel cells. In contrast to its effect in early summer, late-summer drought had no significant effect on fiber and vessel cell development, indicating that sensitivity of wood cell development to drought varies seasonally. 相似文献
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S. Pramod 《Journal of Sustainable Forestry》2013,32(7):661-673
The anatomical changes occurring during transition from juvenile to mature wood were studied in the branch and main trunk of Leucaena leucocephala. To confirm the wood maturity in the 5-yr-old tree, the anatomical features were compared with the adult wood collected from the main trunk of a 15-yr-old tree. In both the branch and wood of the trunk, most of the anatomical features—such as increase in dimensions of fibers and vessel elements, and decrease in frequency of vessel elements and rays—were gradual during radial growth from pith to periphery. A noticeable anatomical change is observed in the transition of triseriate rays to multiseriate rays in the region of wood which is about 5.5 cm away from the pith. The ray dimensions and anatomical features of other elements from the periphery of the branch and 5-yr-old trunk xylem match with that of 15-yr-old main trunk wood. This indicates that in both the branches and main trunk of Leucaena, transition from juvenile to adult or mature wood occurs after the trees have attained 14 cm radial growth. 相似文献
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YANG Shu-min FURUKAWA Ikuo 《林业研究》2006,17(3):247-251
Secondary xylem characteristics and horizontal variations were described in three xerophytic species, Zygophyllum xanthoxylon, Nitraria tangutorum, Tetraena mongolica of Zygophyllaceae native to western China. All the species have obvious growth ring boundaries except sometimes discontinuous in T. mongolica and Z xanthoxylum ring to semi-ring-porosity; simple perforation plate; alternate intervessel pitting; non-septate fibres; paratracheal confluent axial parenchyrna; helical thickenings and heterocellular rays. However the vessel arrangement and quantitative features of vessels were different. Vessel elements tend to be shorter and narrower and more frequent in T. mongolica than in other two species that are hardly different could lead to greater conductive safety. The variation of vessel element length and fibre length along radial direction showed irregular tendency. There was significant difference in both fibre length and vessel element length among-tree and within-tree. Furthermore, the relationships between anatomical features and adaptability to desert environments were also discussed. 相似文献
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Summary The occurrence and distribution of the warty layer in twelve species of hardwoods have been investigated by transmission and/or scanning electron microscopy. Samples were selected on the common feature of reportedly having both primitive vessel types with scalariform perforation plates and more evolutionarily advanced vessel types with simple plates. Among the six angiosperm families represented, warts were generally found in the more primitive-type vessel elements. The more advanced vessel types rarely displayed a warty layer. Warts were also sparse or absent in other specialized cells, the fiber tracheids and libriform fibers. From the evidence presented here and in the literature, the variable presence and morphology of the warty layer in hardwoods (or for wood in general) appears to be attributable to a phylogenetic trend. According to this trend, conifer tracheids and primitive hardwood cells are nearly always warted, but as the cell type becomes more advanced or specialized, it becomes increasingly wart-free. 相似文献