共查询到20条相似文献，搜索用时 15 毫秒
1.
Hikaru Aimi Satoshi Ohmura Tamao Kato Tomoko Nakahara Kazumasa Shimizu 《Journal of Wood Science》2008,54(3):214-219
A purified softwood kraft lignin was modified by ozone treatment and its activity as an acid soil conditioning agent, mainly
focusing on elimination of aluminum toxicity, was assayed by planting experiments. The growth of radish root was examined
in nutrient solution containing CaCl2 and AlCl3 at pH 4.8 with and without modified kraft lignins. The modified kraft lignins that absorbed 1.8 and 3.9 moles of ozone per
C6-C3 unit (M
w 180) showed two effects: the elimination of aluminum toxicity and the acceleration of root growth. The effect on the elimination
of aluminum toxicity was observed even with modified kraft lignin that absorbed 1.0 mole of ozone per C6-C3 unit. The high
molecular weight part of the modified kraft lignin that absorbed 3.9 moles of ozone per C6-C3 unit also proved to be effective
not only in elimination of aluminum toxicity but also in acceleration of root growth. The acceleration effect of ozone-treated
lignins on root growth was also observed under the absence of aluminum in planting experiments.
This report was presented in part at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006 相似文献
2.
To obtain a soil-conditioning agent for acid soil containing excess aluminum ions (AL), kraft lignin was modified by alkaline oxygen treatment. The growth of radish root in solution and in soil containing AL with or without addition of these lignins under controlled pH was examined. We concluded the following. Growth inhibition of radish roots by AL can be removed by adding alkaline oxygentreated lignins in the range of pH 4.5–4.8 in soil. A similar result was obtained at pH 4.5 in a culture solution. The reduction of AL toxicity to plant may be due to the aggregation between AL and the modified lignin at low concentrations of modified lignin because soluble AL could not be detected. On other hand, elongation of radish root was not obviously inhibited, although the soluble AL in the solution culture was at an extremely high level when the dosage of a modified lignin was high. This suggests that the reduction in AL toxicity to plants was due to formation of a complex between AL and acidic groups of the modified lignin.Part of this report was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999 and the 44th Lignin Symposium, Gifu, October 1999 相似文献
3.
The formation of a complex with aluminum by low molecular weight compounds and saponified ozone-treated kraft lignins was
evaluated based on the decrease in pH of their solutions on the addition of 0.1 M AlCl3. Decreases in pH were observed with the solutions containing compounds having adjacent carboxyl groups (oxalic acid), carboxyl/alcoholic
hydroxyl groups (glycolic acid), carboxyl/formyl groups (glyoxylic acid), and phenolic hydroxyl groups (protocatechuic acid)
on the addition of 0.1 M AlCl3. The malonic and phthalic acids, having two carboxyl groups, were also effective. These results show that the compounds were
effective in forming complexes with aluminum. This finding corresponds to the fact that aluminum toxicity is reduced by formation
of a complex with aluminum, except in phthalic acid. The chemical structures stated above in ozone-treated kraft lignins contribute,
at least partly, to the complex with aluminum. The pH of solutions containing saponified ozone-treated kraft lignins and alkaline-treated
kraft lignin decreased more than that without modified kraft lignins on the addition of 0.1 M AlCl3, showing that they were effective in forming a complex with aluminum. The high molecular weight part of saponified ozone-treated
kraft lignin was effective in forming a complex with aluminum and in reducing its toxicity. 相似文献
4.
Pingping Su Kim Granholm Andrey Pranovich Leo Harju Bjarne Holmbom Ari Ivaska 《Wood Science and Technology》2013,47(5):1083-1097
The concentrations and protonation constants of the functional groups like carboxyl and phenolic hydroxyl groups in spruce bark were determined by a potentiometric acid–base titration method. The non-cellulosic carbohydrates in spruce bark were also characterized by acid methanolysis and GC, including determination of the uronic acid units, which are the key units involved in metal sorption. Sorption of metal ions to bark takes place by ion exchange, mainly by complexation to these functional groups. The sorption equilibrium time, studied by using a batch method, was approximately 5 min. The metal sorption capacity of spruce bark and the affinity order of metal ions were studied with four different metal ion mixtures using a column chromatographic method. Because a method of competition was used, concentration of metal ions adsorbed to bark depends on the metal ions present in the mixtures studied. In the sorption experiments with same metal ion mixtures, inner bark of spruce exhibited higher sorption capacity than outer bark. By combination of the results from several experiments, the following affinity order was obtained Fe3+ ? Pb2+ ? Cu2+ ? Cd2+ > Zn2+ > Ni2+ > Ba2+ > Ca2+ > Sr2+ > Mn2+ > Mg2+ ? K+ ~ Na+ ~ Li+. Bark has a great potential as an effective and inexpensive sorbent for removal of metal ions from, e.g., waste water. 相似文献
5.
Lignin characteristics of bast fiber and core in kenaf, bark and wood of paper mulberry and mulberry
The structural features of bast fiber and core lignins in kenaf (Hibiscus cannabinus), bark and wood lignin of paper mulberry (Broussonetia papyrifera (L.) Vent × Broussonetia kazinoki Sieb.) and mulberry (Morus bombycis) were characterized by alkaline nitrobenzene oxidation, ozonation and methoxyl group determination. Bj?rkman lignins were
isolated from bast fiber and core, and bark and wood fractions of the plant samples, and structural characteristics were investigated
by 1H NMR and 13C NMR spectroscopies. Kenaf bast fiber gave very high molar ratio of syringaldehyde to vanillin (S/V) of alkaline nitrobenzene
oxidation products, while methoxyl content was about the same as that of the core fraction. Results of 1H NMR and 13C NMR of Bj?rkman lignin suggested the presence of aliphatic fragments in lignins isolated from paper mulberry and mulberry
bark, but not in kenaf bast fiber. The lower yield of alkaline nitrobenzene oxidation products from bast fiber and bark might
be due to the higher content of condensed structure of lignin compared to core fraction. Total yield of erythronic (E) and threonic (T) acids of ozonation products and the molar ratio of erythronic acid to threonic acid (E/T) of the bast fibers and bark were lower than the corresponding core and wood fractions, suggesting that the contents of arylglycerol-β-aryl
ether intermonomer linkages in the bast fiber and bark lignin were lower than those of the core and wood fractions. Methoxyl
content of bark lignin was lower than the corresponding wood lignin. The methoxyl content of the extract-free kenaf bast fiber
was similar to that of the core fraction, while the values of paper mulberry and mulberry bark were about one-half of the
corresponding wood fractions, respectively. In bark lignins, the methoxyl contents of Klason lignin and Bj?rkman lignin from
bark were lower than those of the extract-free barks. This result suggests that the purity of Klason lignin and Bj?rkman lignins
of bark may be rather low. 相似文献
6.
Pine (Pinus densiflora) bark was chemically modified by grafting with acrylonitrile (AN) through Fenton reaction and conversion of the cyano group
to an amidoxime group by reaction with hydroxylamine. Treatments of pine bark with 160 mM H2O2 at 40°C yielded ~70% grafting in 6-h reaction. After alkali hydrolysis of amidoximated pine bark (AOPB), its adsorption capacity
(q
e) for copper ions was largely increased from 0.5 to 1.8 mmol/g. Adsorption of the hydrolyzed AOPB (HAOPB) followed the pseudo-second-order
kinetic model. Among the metal ions tested, the order of adsorption capacity (q
e) predicted by the kinetic model at equilibrium time was Hg2+ > UO2
2+ > Cd2+ > Cu2+ > Zn2+ > Ni2+. The adsorption process was pH-dependent, and the adsorption equilibrium was observed in the pH range of 6–7 for all the
metal ions. Even though pine bark is a good adsorbent for Hg2+ and UO2
2+ ions, it had a poor affinity for the other ions tested. It was obviously found that HAOPB had very high adsorption abilities
for heavy metal and uranyl ions. 相似文献
7.
Eight different residual lignins isolated from unbleached chemical pulps [sulfite, kraft, alkaline sulfite-anthraquinone-methanol
(ASAM), soda/AQ/MeOH] of spruce and beech were characterized using gel permeation chromatography (GPC), thioacidolysis, and
desulfurization to determine average molecular weight, amounts of uncondensed β-O-4 linkages, and dimeric linkage patterns, respectively. The total amounts of G-CHSEt-CHSEt-CH2SEt and S-CHSEt-CHSEt-CH2SEt were markedly reduced in residual lignins to 40% to 80% of the values for the corresponding milled wood lignins (MWLs).
The number of dimeric units determined by thioacidolysis and desulfurization of the residual lignins was decreased by onehalf
to one-fifth compared to the MWLs. Among the diverse types of dimeric units, reduction of β-1 and β-5 units was significant in most of the residual lignins, with the exception of beech ASAM residual lignin. Compared to beech
MWL, 40% more C6–C3 main monomers were detected, whereas the relative composition of the dimeric units in the beech residual
lignin was very similar to that in the beech MWL. The average molecular weights of residual lignins were less than those of
the MWLs. However, the average molecular weights of the spruce kraft and soda residual lignins were determined to be higher
than those of the corresponding MWLs. 相似文献
8.
Renjun Xiang Liyuan Chai Xilin Zhang Gong Zhang Guifang Zhao 《Frontiers of Forestry in China》2008,3(3):321-325
Leaching of major ions from acid precipitation in a subtropical forest was examined based on an experiment in four sample
sites in Shaoshan City, Hunan Province, China, from January 2001 to June 2002. Results clearly show that when rain passed
through the canopy, pH increased and the evidence of ion uptake was presented for SO4
2−, NO3
−, Mg2+ and NH4
+ ions, especially of NH4
+ and NO3
−. The percentages of dissolved SO4
2−, Ca2+ and Mg2+ show a decreasing trend with increasing rainfall. Percentages of leaching Ca2+, K+ and Cl− ions show an increasing trend as a function of increased pH values. The forest canopy in Shaoshan City has a strong effect
on the uptake of SO4
2− and NO3
− ions under acid rain conditions. The decreasing order of ions leaching in the forest canopy is as follows: K+ > Ca2+ > Cl− > Mg2+ > SO4
2− > NO3
− > NH4
+ > Na+.
__________
Translated from Scientia Silvae Sinicae, 2007, 43(7): 1–4 [译自: 林业科学] 相似文献
9.
１９９８年４月至１９９９年３月对广州市白云山马尾松林和常绿阔叶林、广州市龙眼洞马尾松林两试验点进行了酸雨的监测,并测定和分析了林内穿透雨物理量及化学量,旨在探讨酸雨对不同森林冠层养分淋溶规律的影响。结果表明：（１）广州市酸雨占次数的７９．７％或占降雨量的９５．１％。（２）酸雨通过林冠层后,ｐＨ值明显增加。（３）在马尾松林和常绿阔叶林中,某些单次降雨出现ＳＯ４＾２－、ＮＯ３＾－、ＮＨ４＾＋Ａｌ＾３＋、Ｎａ＾＋的负淋溶现象,说明森林对这些离子（特别是ＮＯ３＾－、Ａａ＾３＋）具有吸收作用;阔叶林全年的ＮＯ３＾－和Ａｌ＾３＋净淋溶为负值,说明阔叶林比马尾松林对这两种离子具有更强的吸收能力。（４）雨水酸度增加（即ｐＨ值减小）,明显提高阳离子Ｃａ＾２＋、Ｍｇ＾２＋、Ｋ＾＋和Ｎａ＾＋冠层淋溶面分率。（５）ＮＨ４＾＋、ＳＯ４＾ 相似文献
10.
Chemical changes in cell wall components of bamboo internode during steam explosion process were analyzed to investigate self-binding
mechanism of binderless board from steam-exploded pulp. More than 30% of xylose on initial mass, which is a major hydrolyzate
of bamboo hemicelluloses, was lost after steam explosion treatment. Bamboo lignin is characterized by the presence of ester-
and/or ether-linked p-coumaric acid to lignin. The content of phenolic hydroxyl groups of lignin isolated from steam-exploded pulp was characterized
2.3 times higher than those of the extract-free bamboo internode due to the cleavage of β-O-4 linkages. Alkaline nitrobenzene
oxidation of the bamboo lignin gave vanillin, syringaldehyde and p-hydroxybenzaldehyde as major products. The content of p-hydroxybenzaldehyde decreased after steam explosion treatment, indicating the cleavage of ester- and/or ether-linked p-coumaric acid. The total yield of erythronic and threonic acids in ozonation products of the extract-free bamboo internode
lignin was 268 mmol (200 g lignin)−1, while those of lignins in the steam-exploded pulp and powdery fraction were 96 and 129 mmol (200 g lignin)−1, respectively, suggesting the significant cleavage of β-O-4 linkages during steam explosion treatment. The cleavage of β-O-4
linkages was also confirmed by 1H- and 13C-NMR spectroscopic observations. 相似文献
11.
N. Yoshizawa A. Inami S. Miyake F. Ishiguri S. Yokota 《Wood Science and Technology》2000,34(3):183-196
Summary Anatomical features of reaction wood formed in two Magnolia species, M. obovata Thunb. and M. kobus DC. which are considered to be among the primitive angiosperms, were observed. In addition, the distribution of guaiacyl
and syringyl units of lignins in the cell walls of normal and reaction wood was examined using ultraviolet (UV)- and visible
light (VL)- microspectrophotometry coupled with the Wiesner and M?ule reactions. The two Magnolia species formed a tension-like reaction wood without possessing the typical gelatinous layer (G-layer) on the upper side of
the inclined stem or branch, in which a radial growth promotion occurred. Compared with the normal wood, the reaction wood
had the following anatomical features: (1) the secondary walls of fiber tracheids lacked the S3 layer, (2) the innermost layer of fiber-tracheid walls showed a small microfibril angle, a fact being similar to the orientation
of the microfibril angle of the G-layer in tension wood, and (3) the amounts of lignin decreased in the cell walls of fiber
tracheids, especially with great decrease in proportion of guaiacyl units in lignins. In addition, VL-microspectrophotometry
coupled with the Wiesner and M?ule reactions adopted in the present study showed potential to estimate the lignin contents
in the cell walls and the proportion of guaiacyl and syringyl units in lignins.
Received: 15 July 1998 相似文献
12.
Laura Vanesa Gómez Ros José M. Espiñeira Federico Pomar Fuencisla Merino Juan Cuello Alfonso Ros Barceló 《Journal of Wood Science》2007,53(4):314-319
Lignins are cell wall phenolic heteropolymers that result from the oxidative coupling of three monolignols bearing p-coumaryl (H), coniferyl (G), and sinapyl (S) units, in a reaction mediated by peroxidases. Here, we report the existence
of a relationship between the Σβ-O-4/ΣO-4 end monomer ratio of the linear lignin fraction, released through the specific cleavage of the alkyl ether linkages by
thioacidolysis, and the G/S ratio of lignins, when this was estimated in differentially evolved vascular land plants. Most
importantly, in the case of angiosperms, Gnetales, and lycopods, the Σβ-O-4/ΣO-4 end monomer ratio was apparently predictable from the proportions at which the G and S units were mixed. In the case of
G lignins (present in basal gymnosperms and ferns), the Σβ-O-4/ΣO-4 end monomer ratio decayed exponentially to increase the O-4-linked dihydroconiferyl alcohol (DHCA) content. The results obtained suggest that the Σβ-O-4/ΣO-4 end monomer ratio of the linear lignin fraction depends intimately on the lignin monomer composition, and, therefore, on
the chemical nature of the radicals derived from three monolignols (coniferyl, dihydroconiferyl, and sinapyl alcohols), whose
gain have been finely tuned during land plant evolution. 相似文献
13.
Brauns’ lignins present in the methanol extracts of fresh birch (Betula pendula) xylem and of sawn birch board subjected to vacuum drying were characterized by 1H and 13C NMR spectroscopy (1D and 2D), IR spectroscopy, gel permeation chromatography (GPC) and colour measurements (CIELab) in order to find out whether Brauns’ lignin could contribute to the colour change of sawn timber that occurred during vacuum drying. The two Brauns’ lignin samples contained about equal amounts of syringylpropane and guaiacylpropane units linked with β-O-4 and β–β side-chain structures. Molecular weight of the Brauns’ lignin of vacuum-dried birch board (acetylated: 5,200 g mol−1) was higher than that of the Brauns’ lignin of fresh birch wood (acetylated: 4,400 g mol−1). The Brauns’ lignin of vacuum-dried wood was also clearly darker and more prominently yellow and red;
between the Brauns’ lignin samples was 23.59. The differences in the molecular weights and colours suggest that the Brauns’ lignin underwent a chemical change during vacuum drying of the wood and that this change may have affected the colour of the wood. 相似文献
14.
The lignin chemical structures of eight species of the Selaginella family, which are primitive vascular plants, were characterized by alkaline nitrobenzene oxidation, acidolysis, and ozonation. Selaginella involvens, Selaginella tamariscina, and Selaginella remotifolia were collected from the University Forest in Chiba, the University of Tokyo, Japan, and Selaginella biformis, Selaginella pennata, S. involvens, Selaginella chrysorrhizos, and unidentified Selaginella species (Selaginella sp.) were collected from northern Thailand. Lignin of all Selaginella species examined in this study was rich in syringyl nuclei. It was confirmed that a considerable portion of syringyl nuclei of Selaginella lignin formed syringylglycerol-β-aryl ether intermonomer linkages. The major diastereomer of arylglycerol-β-aryl ether intermonomer linkages of Selaginella lignins was the erythro-form exhibiting angiosperm lignin characteristics. In addition, lignins of S. involvens, S. tamariscina, and S. remotifolia collected from the University Forest in Chiba, the University of Tokyo, Japan, were isolated according to Björkman’s procedure, and structural features of the lignins were spectrometrically analyzed. It was confirmed that lignin of Selaginella species, which are primitive pteridophytes, was typical guaiacyl-syringyl type as well as being similar to angiosperm lignin. 相似文献
15.
Summary The objectives of this work were to begin developing an experimental system for studying the demethylation of lignin by brown-rot fungi and to examine the influence of selected culture parameters. As substrate for demethylation, we used partially 3-O-demethylated lignin that had been isolated earlier from brown-rotted spruce wood; we remethylated with14CH3I, giving a lignin with both [3-14C]methoxyl and [4-14C]methoxyl groups. This lignin was added to pine wood flakes, which were incubated with selected brown-rot fungi, and the evolved14CO2 was trapped and measured. Of eight fungi examined,Gloeophyllum trabeum andWolfiporia cocos gave the highest rates of mineralization of the14C-methoxyl carbons. With the former but not the latter fungus, methoxyl mineralization was over twice as fast in an atmosphere of O2 than in air. Amending the cultures with ammonium tartrate suppressed mineralization to some extent. Further studies withG. trabeum showed that glutamate lowered the rate of mineralization and that glucose and glycerol sharply suppressed it. Addition of Fe2+ and Mn2+ slightly increased the rate of mineralization. Our results suggest that in unsupplemented cultures the rate-limiting step in methoxyl mineralization is the initial demethylation. Thus the two likely initial C1 products, methanol and formaldehyde (as14C compounds), were mineralized much more rapidly than the methoxyl carbon of the lignin (as was formic acid), and no low molecular weight labeled intermediates from the [14C]-methoxyl lignin accumulated in the cultures. Our results also provide evidence that the spruce lignin was partially polymerized byG. trabeum. Mineralization of the methoxyl carbon of a synthetic [3-14C]-methoxyl lignin was slower than that of the spruce lignin, suggesting either that the synthetic lignin was more recalcitrant or that the [4-14C]methoxyl group in the [3,4-14C]-methoxyl spruce lignin was attacked more readily.We thank Karen L. Martinson and Michael D. Mozuch for excellent technical help, and Tor P. Schultz for valuable suggestions. This research was supported in part by the U.S. Department of Agriculture, Wood Utilization Research Program, Project No. 350-0612, to Mississippi State University.The Forest Products Laboratory is maintained in cooperation with the University of Wisconsin. This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright in the United States. 相似文献
16.
Characterisation, quality assessment and property prediction are several of the major industrial challenges for widespread
acceptance of thermally modified wood (TMW). This study shows the potential of the multivariate analysis of mid-infrared (MIR)
spectral data for the prediction of impact strength, five mechanical parameters in bending, moisture content, weight loss,
density and chemical composition of small specimens of thermally modified beech, Norway spruce and Scots pine woods. Anti-swelling
efficiency was also studied using DRIFT spectroscopy for spruce wood only. Calibrations were successfully accomplished by
partial least-squares regression, with R
Y
2 and Q
CUM2 values >0.96 for 64 out of 67 models. Predictions were also successful, with relative prediction values >0 and RMSEP:SD ratios
<1 in most cases. Changes in the MIR spectra of TMW show that bands arising from the lignin environment and new bands appearing
due to the degradation of carbohydrates, giving negative loadings, were related to strength loss, while those bands arising
from the polysaccharides were associated with property retention. It is concluded that this approach is a powerful tool to
characterise a number of properties of TMW with a single after-treatment measurement. 相似文献
17.
Lignin biochemistry: Biosynthesis and biodegradation 总被引：22，自引：0，他引：22
Prof. T. Higuchi 《Wood Science and Technology》1990,24(1):23-63
Summary Lignin biosynthesis via shikimate-cinnamate pathways in plants, and the biosynthetic differences of guaiacyl-and syringyl lignins between gymnosperms and angiosperms have been elucidated by tracer experiments using 14C labeled precursors and the following enzyme reactions. The formation of guaiacyl lignin but not syringyl lignin in gymnosperms was attributed to the following factors; absence of ferulate-5-hydroxylase, poor affinity of O-methyltransferase toward 5-hydroxyferulate, and lack of activation and/or reduction of sinapatc. A mechanism of lignin-carbohydrate complexes formation in wood cell walls was elucidated based on the reaction of the quinone methide of guaiacylglycerol--guaiacyl ether with sugars, and the analysis of DHP-polysaccharide complexes.The main cleavage mechanisms of side chains and aromatic rings of lignin model compounds and synthetic lignin (DHP) by white-rot fungi and their enzymes, lignin peroxidase and laccase have been elucidated using 2H, 13C and 18O-labeled lignin substructure dimcrs with 18O2 and H2
18O. Side chains and aromatic rings of these substrates were cleaved via aryl cation radical and phenoxy radical intermediates, in reaction mediated only by lignin peroxidase/H2O2 and laccase/O2.Academy Lecture presented at the Cellucon 88 in Japan, International Symposium on New Functionalisation Developments in Cellulosics and Wood, held in Kyoto, Japan, November 28 to December 1, 1988This paper is a conclusion of our investigations on the biosynthesis and microbial degradation of lignin for 30 years in the Research Section of Lignin Chemistry, Wood Research Institute, Kyoto University. The author is greatly indebted to Drs. M. Shimada, F. Nakatsubo, T. Yamasaki, H. Ohashi, M. Tanahashi, Y. Nakamura, H. Kuroda, H. Kutsuki, T. Katayama, Y. Kamaya, T. Umezawa and Messrs. H. Fushiki, M. Ohta, A. Noguchi, H. Namba, T. Habe, S. Kawai, S. Yokota, and T. Hattori for their kind cooperation in these investigations. These invstigations were supported in part by Grant-in-Aid Nos. 548047, 57480058, 59760124, 60760130, 60440015, 61760142, 61560193, 62790250 for Scientific Research, and 1980 Grant-in-Aid for Environmental Science (R-33-8), No. 403064 from the Ministry of Education, Science and Culture of Japan, and a 1980 Weyerhaeuser grant 相似文献
18.
Summary Spruce (Picea mariana) and birch (Betula verrucosa) milled wood lignins were depolymerized with dry hydrogen iodide. 13C NMR spectra of the initial and treated lignins were recorded. The data on chemical shifts of a set of model compounds treated with dry HI were used in the assignment of changes in the spectra of the lignins. The results obtained show that a cleavage of ether bonds in lignin and a substitution of -hydroxy and -alkoxygroups by iodine take place during the treatment. 相似文献
19.
We studied ion distribution in roots and the growth of Cyclocarya paliurus seedlings of three provenances, Huangshan in Anhui, Jiujiang in Jiangxi and Kunming in Yunnan, under conditions of 0, 1,
3 and 5 g/L NaCl stress using X-ray microanalysis. Results show that under NaCl stress of 3 and 5 g/L, the relative contents
of Na+ and Cl− in root tissues increased, while the relative contents of K+, Ca2+ and Mg2+ decreased. With an increase in salinity, the relative content of Na+ in the epidermis and cortex of the root increased, while the relative content of Cl− in the stele and cortex of the root increased markedly. Thus, ions in the root tissues were unbalanced and the ratios K+/Na+ and Ca2+/Na+ decreased, while Na+/(K++ Na++Ca2++Mg2+) increased. The decrease of the K+/Na+ ratio and the substantial increase of Cl− in root tissues contributed to a decline in seedlings survival and reduced the increments for seedling leaf area, height,
basal diameter as well biomass. Our preliminary conclusion is that the level of salt tolerance for the tested provenance seedlings
was in the order of Huangshan > Kunming > Jiujiang, and the threshold of salt tolerance for C. paliurus seedlings was about 1 g/L.
__________
Translated from Scientia Silvae Sinica, 2008, 44(6): 66–72 [틫自: 쇖튵뿆톧] 相似文献
20.
Summary Kraft and ethanol organosolv lignins from Picea abies and Fagus sylvatica were carboxymethylated with bromoacetic acid. Of the total hydroxyl groups in the lignins, 60–70% were carboxymethylated. The reaction led to an increase of the number-average molecular weights. The moisture adsorption of the carboxymethylated products is about one and a half as high as that of the original lignins. There are no remarkable differences between the solubilities of the treated and untreated products.The authors wish to express their appreciation to Mr. Dietrich Meier, Federal Research Organization for Forestry and Forest Products, Hamburg, Federal Republic of Germany, for preparation and donation of lignin samples 相似文献