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1.
柚木花粉离体萌发试验   总被引:1,自引:1,他引:1       下载免费PDF全文
柚木(Tectona grandis L.f.)是世界名贵的用材树种,天然分布于印度、缅甸、泰国和老挝[1],具有生长快、用途广、纹理美观和价格昂贵的特点,已在热带、南亚热带地区广为引种,是世界上人工林种植面积最大的4个树种之一,也是单位面积产值最高的一个造林树种[2-3]。我国引种柚木已有170多年的  相似文献   

2.
对海南岛乐东尖峰岭27年生柚木6个种源的生长及与材质有关特性进行测定与分析,结果表明:种源间树皮厚度、心材宽度、基本密度差异极显著,树高、材积、枝下高、边材宽度差异显著,而胸径、边材年轮数及心材率差异不显著,说明在种源水平上对柚木进行生长和与材质有关特性的改良具有较大的潜力,尤其进行木材生长性状、基本密度和心材宽度的种...  相似文献   

3.
In this study soil samples were taken from the O/A and B horizons of undisturbed forest, active pasture, and 8- to 12-year-old teak and mixed native plantations. Samples were analyzed for K, Ca, Mg, soil organic carbon, pH, exchangeable acidity, bulk density, and compared with a fertility equation. Bulk density was significantly lower in the undisturbed forest than other land uses, suggesting that after approximately 10 years of growth neither plantation lowered bulk density significantly from that of the active pasture. Teak plantations had significantly higher Mg and K (B horizon) and Ca (O/A horizon) concentrations than the undisturbed forest. This trend suggests that exchangeable base concentrations increase when land use changes from undisturbed forest to pasture, then pasture to plantation, with the most pronounced effect of this in teak plantations exhibiting more high fertility plots than other land uses. Soil organic carbon concentration was similar for all land uses except for a significantly lower concentration in teak plantations than in active pasture (O/A horizons). These results suggest that teak plantations may be advantageous for increasing soil fertility but, with respect to restoration of undisturbed forest conditions, present significant deviations in soil chemistry. Options for improved plantations soil management are discussed.  相似文献   

4.
Studies on stem profile of teak (Tectona grandis) hardly exist. This can be possibly attributed to the occurrence of forks that is prevalent on teak trees. Stem profile model was therefore developed for teak in West Africa, which took into account the occurrence of forks. Trees were destructively sampled from Moist Evergreen Forest (MEF), Moist Semi-deciduous Forest (MSDF), Dry Semi-deciduous Forest (DSDF) and Savannah ecological zones in both Ghana and Côte d’Ivoire for the study. A single set of parameters could be used explicitly to predict stem profile of any teak tree, irrespective of country, eco-climatic zone, edaphic variables, site index, tree age, stand density and tree competition. The model efficiency and root mean square error (in relative diameter) were calculated to be 0.97 and 0.053, respectively. The relative position of the forks along the stem bole, with respect to total tree height, was highly variable and did not follow any particular trend, except higher value for the first fork in the Moist Evergreen Forest zone. However, average tree height to the first fork decreased along the ecological gradient from MEF, MSDF and DSDF to Savannah. The extent of diameter reduction due to the forks could be predicted. Relative tree form for zero-forked, one-forked and two-forked trees was calculated to be 0.39, 0.36 and 0.33, respectively. Relative loss of stem volume due to one fork and two forks was estimated to be 6.5 and 13.9%, respectively. The measured stem volume when related to the corresponding predicted value yielded coefficient and intercept not significantly different from unity and zero, respectively, with an r2 value of 0.97.  相似文献   

5.
采集抗寒巨桉单株的萌芽条,通过组培方式繁殖试验苗,以邓恩桉、赤桉、巨桉无性系Eg5、广林九、巨赤桉无性系DH201-2、尾巨桉无性系DH3229等品系作对照,经过多点对比试验的生长观测、抗寒性调查、抗雪压调查以及主要病虫害抗性的测定与调查,综合评价了井冈1号的生长与适应性,并讨论了井冈1号的适宜栽培区域和发展前景。结果表明:井冈1号的抗寒性与邓恩桉、赤桉接近,但抗雪压能力较邓恩桉、DH3229好,井冈1号的保存率、高生长和胸径生长均比邓恩桉、赤桉、Eg5等抗寒品系好。  相似文献   

6.
Extracts of ten Thai indigenous medicinal plants having ethnomedical application in the treatment of dysuria were tested for their Na(+),K(+)-ATPase inhibitory activity. The hexane extracts of Cyperus rotundus and Orthosiphon aristatus showed high potent inhibitory activity on crude enzyme Na(+),K(+)-ATPase from rat brain.  相似文献   

7.
广西大青山柚木人工林生长过程研究   总被引:1,自引:0,他引:1       下载免费PDF全文
[目的]研究柚木人工林生长过程及其与气象因子的相关性,为柚木抚育经营提供理论依据。[方法]以优良、中等和差3种生长类型的30余年生柚木人工林为对象,基于样地调查,选取优势木、平均木、被压木进行树干解析,对比分析其生长过程,应用灰色关联分析法揭示气象因子对柚木生长的影响。[结果]表明:3种生长类型林分柚木胸径、树高和材积生长过程基本一致,各分级木的生长过程亦相似,其胸径平均和连年生长量随年龄的增大呈先增加后逐渐降低的趋势,树高生长整体上呈下降趋势,材积生长则呈递增趋势。各优良林分的林木及各类型林分的优势木,其胸径、材积平均和连年生长量较大,速生期持续时间长,生长衰减慢,而其树高生长量的优势相对不明显;30余年生时柚木尚未达数量成熟龄。各类型林分间柚木生长与气象因子关系的差异仅体现在胸径,优良林分胸径连年生长量主要受极端低温影响,而中等和差林分则与年均降水量相关性最大;各分级木间柚木生长与气象因子的关系无明显差异;影响树高和材积连年生长量的最主要气象因子分别为年均降水量和年均气温。[结论]柚木各生长类型及分级木的生长过程整体趋势基本一致,其差异主要体现在生长量大小和快速生长期长短。约30年生柚木人工林仍未达到数量成熟,后期抚育经营对于其优质大径材高效培育仍不可忽视。  相似文献   

8.
Two new (1 and 2) and one known (3) β-dihydroagarofuran sesquiterpenes were isolated from the fruits of Celastrus orbicultus Thunb. Their structures were elucidated as 1β,13-diacetoxy-8β,9β-dibenzoyloxy-β-dihydroagarofuran (1), 1β,13-diacetoxy-8α-hydroxy-9β-benzoyloxy-β-dihydroagarofuran (2), and 1β,6α,13-triacetoxy-9α-benzoyloxy-β-dihydroagarofuran (3), on the basis of spectroscopic data analyses. All the compounds exhibited inhibitory effects on LPS-induced nitric oxide production in murine microglial BV-2 cells.  相似文献   

9.
Rhizophagus grandis (Coleoptera: Rhizophagidae) is an important predator of Dendroctonus valens which is an invasive alien pest attacking pine trees in China. It was first introduced into China in 2000 and mass rearing techniques had been developed by the authors since then. This paper dealed with the study on the developmental threshold temperature and the effective accumulated temperature of R. grandis. The result showed that the developmental threshold temperatures of egg, larva and pupae were 3.59±2.92 ℃, 1.96±0.73 ℃ and 9.27±1.19 ℃ respectively, and the effective accumulated temperatures were 98.32±16.26 degree-day, 296.94±12.45 degree-day and 449.67±53.19 degree-day respectively. Therefore, the total effective accumulated temperature from egg to pupa was 844.93 degree-day.  相似文献   

10.
Two new flavane gallates were isolated from the leaves of Plicosepalus curviflorus. The structure of the new compounds was established as 2S,3R-3,3′,4′,5,7-pentahydroxyflavane-5-O-gallate (1) and 2S,3R-3,3′,4′,5,5′,7-hexahydroxyflavane-4′,5-di-O-gallate (2), respectively. In addition, seven known compounds (−)-catechin (3), quercetin (4), lupeol (5), β-sitosterol (6), pomolic acid (7), β-sitosterol 3-O-β-d-glucopyranoside (8) and 4-methoxycinnamic acid (9) were reported for the first time from the genus Plicosepalus. Compounds 1, 2 and 3 were investigated for their hypoglycemic activity and showed significant hypoglycemic activity in Swiss Albino mice.  相似文献   

11.
To investigate the phillyrin-producing endophytic fungi from the medicinal plant Forsythia suspensa, a total of 24 strains of endophytic fungi were isolated from the healthy stems, leaves and fruits of the plant, 9 from stems, 5 from leaves, and 10 from fruits respectively. All fungal isolates were fermented in liquid PDA medium and their extracts were preliminary analyzed by TLC. One isolated strain G10, which was from the fruit of F. suspensa, had the same Rf value as authentic phillyrin. The potential phillyrin-producing fungus G10 was further analyzed by HPLC and HPLC-MS, and the results showed that the isolate G10 possessed of a retention time and ion peaks identical with the authentic compound phillyrin. The isolate G10 was identified as Colletotrichum gloeosporioides based on the morphological characteristics and ITS sequence analysis. The current research indicates that the numerous endophytic fungi inside the medicinal plants are precious resource for the pharmaceutical natural products that are originally from the plants.  相似文献   

12.
[目的]探讨巨桉林中蚂蚁群落的生态状况及植被变化后蚂蚁群落的响应,为今后土地利用方式的选择优化及生态恢复策略的制定提供依据。[方法]于2012年10月和2013年4月采用Winkler袋法调查云南省绿春县的巨桉人工林和天然次生林中枯落物层蚂蚁群落。[结果]共采集枯落物层蚂蚁5亚科34属66种2 118头。四个样地间枯落物层蚂蚁的物种丰富度有显著差异(GLM,t=-2.068,P=0.039),相对多度无显著差异(GLM,t=-0.174,P=0.863),其中巨桉林E1蚂蚁物种丰富度最高,N2最低;天然次生林N1蚂蚁多度最高,E2最低。巨桉林枯落物层蚂蚁群落结构与天然次生林无显著差异(ANOSIM Global R=0.5,P=0.333)。巨桉林中的指示物种为菱结大头蚁和东方小家蚁,天然次生林中的指示物种为红足厚结猛蚁。枯落物层厚度与蚂蚁物种丰富度显著负相关,枯落物层其它指标与蚂蚁物种丰富度和多度均无显著相关性。[结论]干扰少、林下植被丰富的人工巨桉林对枯落物层蚂蚁群落多样性的保护具有积极意义。  相似文献   

13.
Climate change resulting from increased atmospheric carbon dioxide (CO2) and shortages of fossil fuels such as petroleum are major problems worldwide. Under these conditions, demand for woody biomass resources is increasing. We investigated the feasibility of using fast-growing Eucalyptus grandis for material production. Samples of E. grandis were collected from four plantations in different latitude divisions, including tropical and subtropical Brazil and subtropical Argentina. Various xylem qualities were measured and related to the lateral growth rate. Lateral growth rate did not significantly affect the longitudinal released strain of the surface growth stresses or the xylem density at any of the sampling sites. Higher lateral growth rate, higher values of xylem density, and lower absolute values of the released strain were observed in plantations closer to the equator. Higher growth rates in tropical climate promote longer fiber length. In subtropical plantations, smaller diameter trees will produce tension wood with smaller microfibril angles. Planting E. grandis closer to the equator thus produces higher quality wood than in plantations at lower latitudes.  相似文献   

14.
Polycarpol, sitosterol and sitosterol-3-O-β-D-glucoside isolated for the first time from Piptostigma preussi (Annonaceae) occur regularly in some Annonaceae such as Piptostigma genus. Polycarpol exhibits interesting antitrypanosomal activity with an ED50 value of 5.11 µM on Trypanosoma brucei cells. Moreover, it inhibits T. brucei glycolytic enzymes GAPDH and PFK with IC50 values of 650 and 180 µM respectively.  相似文献   

15.
Codonopsis pilosula is a perennial species of flowering plants propagated in Northeast Asia. A water-soluble polysaccharide, CPPS3, was extracted from the root of Codonopsis pilosula by boiled water extraction and ethanol precipitation. The molecular weight was estimated to be 7.4 × 104 Da determined by using Gel permeation chromatography. Monosaccharide composition and the structure of the polysaccharide were determined by gas spectroscopy, Fourier transform IR (FT-IR) spectroscopy, NMR spectroscopy and mass spectroscopy and some chemical method analysis was made. The components were galactose, arabinose and rhamnose in the molar ratio of 1.13:1.12:1. The main chain of CPPS3 is illustrated to be (1→3)-linked-β-GalpNAc, (1→3)-linked-α-Rhap and (1→2,3)-β-Galp.  相似文献   

16.
Two new cerebrosides have been isolated from the whole plants of Euphorbia peplis L. The structures were established by FT-IR spectroscopy, FAB MS, EI-MS, ESI-MS, 1D and 2D NMR spectroscopy.  相似文献   

17.
Nitrogen fertilizer inputs increased sharply over the last decade in Brazilian eucalypt plantations. Due to the economic and potential environmental cost of fertilizers, mixed plantations with N-fixing species might be an attractive option to improve the long-term soil N status. A randomized block design was set up in southern Brazil, including a replacement series and an additive series design, as well as a nitrogen fertilization treatment. The development of mono-specific stands of Eucalyptus grandis (0A:100E) and Acacia mangium (100A:0E) was compared with mixed plantations in proportions of 1:1 (50A:50E), and other stands with different densities of acacia for the same density of eucalypts. The objective was to assess the effect of inter-specific interactions on the early development of the two species. Aboveground biomass was measured 6, 12, 18 and 30 months after planting, sampling 6–10 trees of each species per treatment at each age, and allometric equations were established in 0A:100E, 100A:0E, 50A:50E and 50A:100E. The height and basal area of E. grandis seedlings were enhanced by 12% and 30%, respectively by N fertilization at age 1 year. Inter-specific competition led to a stratified canopy, with suppression in acacia growth earlier for basal area than for height. The mean number of stems per acacia tree at 36 months after planting was significantly higher in pure stands (3.7), than in 50A:50E (2.7) and in the additive series (between 1.6 and 1.8). H/D ratios were highly sensitive to inter-tree competition for the two species. The suppressed acacia understorey in mixed-species stands did not influence biomass production and partitioning within eucalypts. This pattern led to biomass accumulation combining the two species in 50A:100E that was about 10% higher than in 0A:100E, from age 12 months onwards. Aboveground net primary production (ANPP) amounted to 25 Mg ha−1 and 37 Mg ha−1 from age 18 to 30 months in 100A:0E and 0A:100E, respectively. Acacia ANPP in 50A:100E amounted to 2 Mg ha−1 over the same period, as a result of substantial inter-specific competition. An increment in biomass production in these very fast-growing eucalypt plantations was achieved introducing acacia as an understorey and not in the 50A:50E design, as observed in other studies.  相似文献   

18.
A new secoiridoid named chinensisol (1) along with twenty known compounds were isolated from the 95% ethanol extract of Cortex fraxini. Their structures were elucidated on the basis of NMR, MS, IR and UV spectral evidences. The quinone reductase (QR) inducing activities of the compounds were evaluated and the results showed that compounds 1, 9 and 14 had moderate QR inducing activities with CD values (concentration required to double the specific activity of QR) of 72.4 ± 7.7, 34.3 ± 3.3 and 42.0 ± 0.4 μM respectively.  相似文献   

19.
In the course of searching for cytotoxic terpenoids from medicinal plants in China, two new eudesmane sesquiterpenoids, 5α-hydroxy-13-methoxy-7αH,11αH-eudesm-4(15)-en-12,8β-lactone (1) and 1β-hydroxy-7αH,11αH-eudesm-4(15)-en-12,8β-lactone (2), along with fourteen known sesquiterpenoids were isolated from the whole plant of Carpesium divaricatum. The structures of new compounds were determined using spectroscopic methods, including IR, HRESIMS, and 1D and 2D NMR spectroscopy. The cytotoxicity of selected sesquiterpene lactones against human oral epidermoid carcinoma (KB), human breast cancer (MCF-7) and human hepatoma (HepG-2) cells was also evaluated by MTT method.  相似文献   

20.
Two new benzofuran derivatives, 2-(4′-hydroxybenzyl)-5,6-methylenedioxy-benzofuran () and 2-(4′-hydroxybenzoyl)-5,6-methylenedioxy-benzofuran (), along with 8 known compounds were isolated from 60% EtOH extract of the fibrous roots of Liriope spicata var. prolifera. Their structures were elucidated on the basis of extensive spectroscopic analysis. In an in vitro bioactive assay, the two new benzofuran derivatives showed anti-inflammatory activity. Compounds 1 and 2 exhibited significant inhibitory activity against neutrophil respiratory burst stimulated by phorbol 12-myristate 13-acetate (PMA) with IC50 value of 4.15 ± 0.07 and 5.96 ± 0.37 μM, respectively.  相似文献   

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