Homogenate extraction technology of camptothecine and hydroxycamptothecin from Camptotheca acuminata leaves     

Wei-guo Shi  Yuan-gang Zu  Chun-jian Zhao  Lei Yang 《林业研究》2009,20(2):168-170

Camptothecine (CPT) and hydroxycamptothecin (HCPT), two kinds of anti-cancer alkaloids, were extracted from Camptotheca acuminata leaves using homogenate extraction technology under different conditions such as the ratio of material to liquid, ethanol concentration, and homogenate time. The optimum technology parameters for homogenate extraction of CPT and HCPT from C. acuminata leaves were determined as homogenate time at 8 min, ethanol concentration at 55% and the ratio of material to liquid at 1:15 (g:mL). By using the optimized parameters, we obtained 0.639‰ extraction rate for CPT and 0.437‰ for HCPT. The extraction yields of CPT and HCPT extracted by homogenating technology were higher than those by other extractive methods, such as ultrasonic, reflux, shaking in water bath. It is concluded that the homogenate extraction technology was an efficient method for extracting CPT and HCPT from C. acuminata leaves, with characteristics of less extraction time and high yield. Foundation project: This research was supported by National Key Technology R & D Program (grant no. 2006BAD18B04). Biography: SHI Wei-guo (1970–), male, Ph. D. candidate in Northeast Forestry University, Harbin 150040, P. R. China.)  相似文献   

Synergistic contribution of hydrosulfide and carbonate anions to the β-O-4 bond cleavage of lignin model compounds in a green liquor pretreatment for enzymatic hydrolysis of lignocellulosic materials     

Feng Gu  Pattaraporn Posoknistakul  Satoko Shimizu  Tomoya Yokoyama  Yongcan Jin  Yuji Matsumoto 《Journal of Wood Science》2014,60(5):346-352

To examine why green liquor (GL) pretreatment of lignocellulosic materials effectively facilitates enzymatic saccharification under conditions milder than those of a common alkaline cooking process, dimeric β-O-4 type lignin model compounds with and without free phenolic hydroxyl group were reacted in several alkaline solutions including a model solution of GL, which mainly contains Na₂CO₃ and Na₂S. The β-O-4 bond of the phenolic model compound was cleaved with a sufficient rate in the model solution of GL. The β-O-4 bond cleavage of the non-phenolic model compound was more frequent in the model solution of GL than in other alkaline solutions. These results suggest that β-O-4 bonds present in lignocellulosic materials are effectively cleaved in a GL pretreatment. It was also suggested that HS^? and CO₃ ^2? synergistically contribute to the β-O-4 bond cleavage of the non-phenolic model compound under GL pretreatment conditions.  相似文献   

高效液相色谱法测定羟基喜树碱含量方法的研究     

马梅芳  于涛等 《林业研究》2002,13(2):144-146

The determination method of 10-hydroxycamptothecin inCamptotheca acuminatu fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C₁₈(4.6×250 mm) column with mobile phase of acetonitrile-water (3:7, V:V), flow rate 1 mL·min⁻¹ and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits ofC. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60°C for 50 minutes. Foundation Item: This paper was supported by National Natural Science Foundation of China (No. 30070086). Biography: MA Mei-fang (1976-), female, Graduate Student of Northeast Forest University. Responsible editor: Song Funan  相似文献   

Effect of planting density on plant growth and camptothecin content of Camptotheca acuminata seedlings     

Wei Huan-yong  Wang Yang  Wang Zhen-yue  Yan Xiu-feng 《林业研究》2005,16(2):137-139

C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25, 44 and 100 plants·m⁻²) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem, and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area ofC. acuminata seedlings all showed highest values at the planting density of 25 plants·m⁻². CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100 plants·m⁻², while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m⁻². It is concluded that for the purpose to get raw materials with more CPT fromC. acuminata, the optimal planting density ofC. acuminata seedlings should be designed as 25 plants·m⁻². Foundation item: This paper was supported by the National Natural Science Foundation of China (No. 3970086) and Heilongjiang Province Foundation for Distinguished Youth Scholars (JC-02-11) Biography: Wei Huan-yong (1978-), male, Graduate in College of Life Sciences, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Zhu Hong  相似文献   

Extraction of antioxidants from eucalyptus (Eucalyptus globulus) bark     

Gonzalo Vázquez  Jorge Santos  M. Sonia Freire  Gervasio Antorrena  Julia González-álvarez 《Wood Science and Technology》2012,46(1-3):443-457

The extraction of phenolic compounds from eucalyptus (Eucalyptus globulus) bark was examined with the aim of analyzing the potential of the extracts as natural antioxidants. Experiments were planned according to a 2³ factorial design to analyze the influence of temperature and Na₂SO₃ and NaOH concentrations in aqueous solutions on extraction yield, extract total phenols content, ferric reducing antioxidant power (FRAP), and number- and weight-average molecular weights. Extract total phenols content and FRAP antioxidant activity in the ranges 0.91–2.58?g gallic acid equivalent (GAE)/100?g oven-dried bark and 4.70–11.96?mmol ascorbic acid equivalent (AAE)/100?g oven-dried bark, respectively, demonstrated the potential of eucalyptus bark as a source of antioxidant compounds. Extraction at the highest temperature (100°C), the lowest Na₂SO₃ concentration (1.5% on oven-dried bark), and without NaOH provided the highest extract total phenols content and FRAP antioxidant activity. Those eucalyptus bark extracts with lower molecular weight showed higher antioxidant activity. Matrix-assisted laser desorption ionization time-of-flight and reverse-phase high-performance liquid chromatography electrospray ionization time-of-flight mass spectrometry revealed the presence of polygalloyl glucoses, catechin, epicatechin, ellagic acid, quercetin-3-o-rhamnoside, and isorhamnetin in eucalyptus bark aqueous extracts.  相似文献   

MALDI-TOF, HPLC-ESI-TOF and 13C-NMR characterization of chestnut (Castanea sativa) shell tannins for wood adhesives     

Gonzalo Vázquez  Antonio Pizzi  M. Sonia Freire  Jorge Santos  Gervasio Antorrena  Julia González-Álvarez 《Wood Science and Technology》2013,47(3):523-535

MALDI-TOF, HPLC-ESI-TOF and 13C-NMR techniques were used to analyse the structure of non-purified aqueous chestnut shell tannin extracts. In addition, the influence of the extraction agent (water or aqueous solutions of Na₂SO₃ and/or NaOH) on tannin structure was analysed by MALDI-TOF in order to select the extract with the best properties for wood adhesives. Using HPLC-ESI-TOF, catechin/epicatechin, gallocatechin/epigallocatechin, dicatechin structures, dicatechin structures without a hydroxyl group, galloyl-glucoses and ellagic acid were identified as the main monomeric components in the aqueous extract. 13C-NMR and MALDI-TOF spectra revealed that extracts are mostly composed of procyanidin and prodelphinidin structures although prorobinetidins might be also present. MALDI-TOF spectrometry was used to identify the extract oligomeric components. Extractions with Na₂SO₃ and/or NaOH produced changes in the predominant structures in the extracts and on the amount of sugar units linked to the flavonoid structures, which decreased in the presence of Na₂SO₃. Extract obtained using low Na₂SO₃ and NaOH concentrations (1.5 and 0.75 %, respectively) was selected as more suitable for wood adhesive preparation.  相似文献   

Fractional isolation and structural characterization of mild ball-milled lignin in high yield and purity from <Emphasis Type="Italic">Eucommia ulmoides</Emphasis> Oliv     

Feng Xu  Jian-Xing Jiang  Run-Cang Sun  Jiang-Ning Tang  Jin-Xia Sun  Yin-Quan Su 《Wood Science and Technology》2008,42(3):211-226

Sequential extractions of the mild ball-milled Eucommia ulmoides Oliv with 80% neutral dioxane, 75% dioxane containing 0.025 M HCl, 75% dioxane containing 0.1 M NaOH, 60% ethanol containing 0.5 M NaOH, 5% KOH, 5% NaOH, and 8% KOH at 75°C for 3 h released 91.3% of the original lignin. The results showed that the procedure for extracting lignin from the mild ball-milled wood with mild alkaline organic solvent was more efficient than the traditional method of neutral and mild acidic dioxane extractions. The structure of the seven lignin fractions were analysed using wet chemical analysis, such as alkaline nitrobenzene oxidation, FT-IR, and solution-state ¹H, ¹³C, and ³¹P NMR techniques. It is clear that the sequential mild acidic and alkaline organic solvent extractions of the mild ball-milled E. ulmoides Oliv offered significant yield improvements over the traditional signal acidolysis procedure for isolating lignin from wood, and the alkaline organic solvent extraction led to more lignin release than that of the mild acidolysis. This new procedure proposed in this study could be used for the lignin structural analysis, whereby wood is mild ball-milled and successively extracted with both mild acidic and alkaline organic solvents as well as aqueous alkalis to produce lignin fractions with high yield and purity and representing the total lignin in wood.  相似文献   

外源糖溶液和高浓度CO2处理对白桦叶片糖和蛋白质含量的影响   总被引：1，自引：0，他引：1  

周玉梅  杨传平  王淑娟  吴月亮  王文章  韩士杰 《林业研究》2003,14(1):61-63

3年生白桦同时接受3种外源糖溶液(蔗糖、果糖、葡萄糖)和3种高浓度CO2(700、1400、2100μL·μL-1CO2)处理.处理1个月后,测定了叶片的总糖、蔗糖、果糖和蛋白质含量.结果表明:在700μL·L-1和1400μL·L-1 CO2下,外源糖溶液增加了叶片的可溶性糖和蛋白质含量,其中外源蔗糖的效果最好:外源糖溶液与2100μL·L-1CO2结合,会抑制叶片积累总糖和蛋白质:在700μL·L-1和1400μL·L-1CO2下,喷施葡萄糖、果糖的叶片在蛋白质含量上没有明显差别:同700、1400μL·L-1CO2相比,除喷施果糖植株外,2100μL·L-1 CO2明显增加了叶片的总糖、蔗糖、果糖和蛋白质含量:在喷施同种外源糖溶液的情况下,叶片的糖含量与CO2浓度呈正相关性.图6参7.  相似文献   

High-yield pulping of aspen wood: Relation between pulp properties and fibre characteristics by multiple linear regression     

Dr. Félix Carrasco  B. V. Kokta  A. Ahmed  J. J. Garceau 《Wood Science and Technology》1994,28(6):409-421

Summary High-yield pulps have been obtained by means of steam explosion pulping. This process was carried out as follows: 1) chips soak impregnation (60 °C, 24 h, L/C = 6) in solutions containing 8% Na₂SO₃ and a variable concentration of either Na₂CO₃ or NaHCO₃, ranging from 0 to 2%; 2) cooking at high temperature (190–200 °C) for short time (2-1 min); 3) rapid pressure release. This work shows that mechanical properties were substantially improved when adding a second chemical to the Na₂SO₃ impregnation solution. Moreover, refining energy requirement was significantly reduced. However, the higher chemical charge used made the optical properties drop. In this paper, mathematical models have been proposed in order to accurately predict specific refining energy and paper properties from sulfonate content and pulp yield. In addition, the relative importance of these two parameters has been studied.Thanks are due to the Natural Science and Engineering Council of Canada (NSERC) and Fonds pour la Formation de chercheurs et l'aide à la recherche of Quebec (FCAR) for their financial support.  相似文献   

盐碱胁迫对平欧杂种榛生长及叶片内源激素含量的影响          下载免费PDF全文

张丽  贾志国  马庆华  王贵禧 《林业科学研究》2015,28(3):394-401

利用中性盐NaCl、碱性盐Na2CO3及混合盐碱(NaCl∶ Na2CO3=1∶1)设置3种盐碱胁迫处理,研究平欧杂种榛“辽榛3号”在不同类型、不同浓度的盐碱胁迫下生长指标及内源激素的变化,分析各内源激素与生长指标的相关关系.结果表明:3种盐碱胁迫对平欧杂种榛株高、新梢长度及叶片数净生长量、地上部生物量、总生物量抑制作用明显,且NaCl胁迫＞混合盐碱胁迫＞Na2CO3胁迫,而各处理根冠比显著增加;低浓度盐碱胁迫对地径有明显的增粗效应,在50、100 mmol·L-1 Na2CO3胁迫下,地下部生物量显著增加;此外,NaCl胁迫还显著降低了平欧杂种榛叶片含水量.3种胁迫条件下,平欧杂种榛叶片的ABA含量明显增加,且(GA+ IAA+ ZR)/ABA比值与对照相比均显著降低,同时发现Na2CO3胁迫下ABA积累更快,且与胁迫浓度无关,而NaCl胁迫下ABA含量与胁迫浓度显著正相关.相关分析表明:(GA+ IAA+ZR)/ABA比值与株高、新梢长度、新梢叶片数存在显著正相关,而与根冠比呈极显著的负相关.由上可知,平欧杂种榛在中性盐下的生长指标受抑制程度大于碱性盐和混合盐碱,不同盐碱胁迫下内源激素响应特征也存在差异,表明平欧杂种榛对Na2CO3的耐受力高于NaCl.  相似文献   

紫椴花多糖的超声提取最佳条件和含量测定     

穆立蔷  刘立平  马大龙 《林业研究》2010,21(1):77-80,I0003

设置7个萃取温度（25,35,45,55,65,75,85。C）和萃取时间（30,40,50,60,70,80,90min）来选择超声提取紫椴花中多糖的最佳提取温度和提取时间。利用分光光度法对紫椴花中的多糖含量进行了分离和测定。结果表明：最佳提取条件为提取温度为75℃,提取时间为52min。经蒽酮—硫酸显色,于580nm处测定,其多糖的含量为9．74％,RSD=0．47％（n=3）。此测定方法简便,样品溶液在4h内显色稳定,重现性较好,平均回收率为99．48％&#177;1．01％,RSD=0．112％（n=3）。  相似文献   

Responses of germination and radicle growth of two Populus species to water potential and salinity   总被引：8，自引：0，他引：8  

Li Li Zhang Xi-ming Michael Runge Li Xiao-ming He Xing-yuan 《中国林学(英文版)》2006,8(1):10-15

The effects of water potential, NaCl and Na2SO4 on germination and radicle growth of two riparian tree species, Populus euphratica Oliv. and P. pruinosa Schrenk (Salicaceae), were tested. Growth chamber studies revealed an optimum temperature range for seed germination of both species between 15-35℃. The final germination percentage of both species decreases with decreasing water potential in all types of solution applied in the experiments. P. pruinosa was less tolerant to low ψw stress than P. euphratica, especially in salt solutions. Germination percentages fell below 20% for P. pruinosa at -0.6 MPa (NaCl) or -0.4 MPa (Na2SO4) and for P. euphratica at -1.2 MPa (NaCl) or-0.6 MPa (Na2SO4). Radicle growth of both species was inhibited by high concentrations of PEQ NaCl and Na2SO4. However, growth was enhanced at -0.13 and -0.29 MPa in PEG or at -0.13 MPa in NaCl solutions compared to distilled water. Radicle growth of P. euphratica was higher than that of P. pruinosa. Germination and radicle growth of both species exhibited ion toxicity. Na2SO4 was more toxic than iso-osmotic solutions of NaCl. Radicle growth proved to be more sensitive than seed germination. Thus, flooding does not only yield the necessary soil moisture for germination but also favors seedling establishment of both species through leaching of salts from the soil surface. The different sensitivity of the species during their early growth stages might, moreover, contribute to the observed differences in their distribution in the Talim Basin (northwest China).  相似文献   

常山胡柚天然色素的初步鉴定及其稳定性研究   总被引：2，自引：0，他引：2       下载免费PDF全文

时海香  仲山民 《林业科学研究》2008,21(6):852-856

以超临界CO2萃取得到的常山胡柚外果皮色素粗产品为原料,对其进行初步鉴定,并研究了pH值、温度、光照、金属离子、氧化还原剂等对常山胡柚天然色素稳定性的影响。结果表明;常山胡柚天然色素属于黄酮类物质,用NaNO2-Al(NO3)3比色法进行定量分析得知,色素液中含有黄酮类的量为2.01 g.L-1,该色素在碱性和中性溶液中较稳定,在酸性溶液中不稳定。光照、高温和氧化剂都会对该色素造成破坏;该色素能耐弱还原剂。低浓度Na 的存在会使最大吸光度增加,具有增色作用,高浓度Na 的存在能使最大吸光度降低。随着Zn2 浓度的增加,色素液的色泽明显变淡,吸光度急剧下降。Ca2 、Cu2 影响趋势基本一致,加入的离子浓度小于0.05 mol.L-1时,色素残存率缓慢下降;大于0.05 mol.L-1时,色素残存率有低幅增加趋势。Mg2 的加入会让色素残存率变小。  相似文献   

Consumption of O<Subscript>2</Subscript>, evolution of CO<Subscript>2</Subscript> and reduction of Cr(VI) during fixation of chromium based wood preservatives in wood     

M. Humar  M. Petrič  F. Pohleven  M. Šentjurc 《Wood Science and Technology》2002,36(4):309-318

Norway spruce dust was impregnated with aqueous solutions of chromated copper wood preservatives. Immediately after treatment, observation of CO₂ evolution and O₂ consumption were performed. Significant quantities of CO₂ were released during reaction of chromium (K₂Cr₂O₇) containing solutions with wood or brown rotted wood. Nevertheless, during reaction of cellulose with these preservatives we did not observe evolution of CO₂. The presence of copper did not influence on concentration of CO₂. Opposite to CO₂ evolution, treatment of wood and brown rotted wood resulted in O₂ consumption. The oxygen concentration decrease in the measuring chamber was approximately 5 times greater than increase of concentration of carbon dioxide. Electron paramagnetic resonance (EPR) observations of chromium fixation showed that chromium is reduced from Cr(VI) to Cr(III) with Cr(V) as an intermediate on wood, brown rotted wood and cellulose. However, the reduction on wood and brown rotted wood was faster than the reduction on cellulose, as determined from changes of Cr signals in EPR spectra. So, evolution of CO₂ and consumption of O₂ as well as EPR signals of Cr species thus indicate that brown rotted wood, consisting of lignin and hemicelluloses in contact with Cr(VI) reacts more intensively than cellulose, and possibly, oxidation mechanisms of lignin and cellulose with Cr(VI) are different. Received: 20 July 2000  相似文献   

Protection and fastness of green color of moso bamboo (Phyllostachys pubescens Mazel) treated with chromium-based reagents     

Shang -Tzen Chang  Ting-Feng Yeh 《Journal of Wood Science》2001,47(3):228-232

The attractive green color of moso bamboo (Phyllostachys pubescens Mazel) culms fades without chemical treatment. Chromated copper arsenate (CCA) has been used to protect the green color of bamboo, but CCA is harmful to factory workers and the environment. To overcome the toxicity of arsenic in CCA, two chromium-based formulas developed by the authors, chromated copper phosphate (CCP) and chromated phosphate (CP), were evaluated for their protection of the green color of moso bamboo. The results revealed that bamboo treated with CP had a greener color than those treated with CCA or CCP. The concentration, treatment time, and CrO₃/H₃PO₄ ratio in CP solution greatly affected the color of moso bamboo culms. The attractive green color, which resembles the color of fresh-cut moso bamboo, was obtained by treating bamboo with 2% CP solution at 60°C for 3h, using a 11 CrO₃/H₃PO₄ ratio in aqueous solution. In addition, the CP-treated moso bamboo exhibited excellent green color fastness in both accelerated ultraviolet lightfastness testing and outdoor weathering exposure.  相似文献   

Agrobacterium-mediated genetic transformation of Camptotheca acuminata     

WANG Hui-mei ZU Yuan-gang 《林业研究》2007,18(4):316-318

UGPase gene related with wood cellulose synthesis was transferred into C. acuminata using the method of Agrobacte- rium-mediated genetic transformation, and an efficient transformation system was developed for C. acuminata on the basis of evaluations of several factors affecting Agrobacterium-mediated DNA transfer rate. The highest transformation rate was achieved when pre-cultttred leaf explants were infected with an Agrobacterium culture corresponding to OD600 （0.5） for 10 min, and cultured on explant regeneration medium for three days. The results of Southern hybridization showed that genomic DNA of the kanamycin-resistant shoots to an UGPase gene probe substantiated the integration of the transgene. Transformation efficiency （6%） was achieved under the optimized transformation procedure, This system should facilitate the introduction of important useful genes into C, acuminata.  相似文献   

杉木精油的制备及其成分分析的研究   总被引：10，自引：0，他引：10  

黄洛华  秦特夫OHIRATatsuro 《林业研究》2004,15(1):80-82

本文研究了杉木精油的提取方法及其化学成分。采用了四种蒸馏装置来提取杉木精油。结果表明：大部分精油在蒸馏的2小时内被提取出；装置3具有较高的提取效率；杉木精油的主要化学组成为松柏醇；精油获得率随蒸馏时间段的增加而逐渐减小；采用CO2-超临界流体萃取法提取杉木精油，压力为100kg／cm^2和温度为40℃时为其最佳条件。图1表4参10。  相似文献   

Extraction of betulin from bark of Betula platyphylla by supercritical carbon dioxide extraction     

ZHANGYu-hong YUTao WANGYang 《林业研究》2003,14(3):202-204

Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjiang Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO2 extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extraction conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 ℃. The velocity of flow of liquid CO2 was at 10 kg/h. The pressure and temperature in separation vessel were at 5.5 Mpa and 50 ℃, respectively.  相似文献   

Difference in cutting age for highest profit by methods for calculating CO<Subscript>2</Subscript> emission trading and the price of CO<Subscript>2</Subscript>     

K. Sakata  Y. Konohira 《Journal of Forest Research》2003,8(2):0111-0115

 The amounts of CO₂ that are absorbed and emitted by forest in a model stand area were determined using two calculation methods, namely the flow approach and the stock approach for emission trading, to understand the relationships between the cutting age for the highest profit rate (CAHPR; optimum tree ages to be cut so as to maximize the profit) and (1) the prices of CO₂ and (2) the balance between CO₂ emission and absorption. The resultant CAHPR differed between these two CO₂ accounting methods, which give different tree ages for maximum log volume yield. A rise in CO₂ price caused the CAHPR to approach the tree age of maximum log volume in the flow approach method, and to deviate from the tree age of maximum log volume in the stock approach method. Even at the same CO₂ price, the CAHPR differed between the CO₂ accounting methods. At low CO₂ prices, the CAHPR did not affect situations where the difference of average profit is large by cutting age. On the other hand, the CAHPR was greatly affected at low CO₂ prices when the mean log volume growth changed with tree age. These trends were found to be universal. Received: September 18, 2001 / Accepted: October 25, 2002 Acknowledgments This study is one of the fifth science study subsidy projects of the Japan Forest Technology Association. Correspondence to:K. Sakata  相似文献   

Organic acid exudation from the roots of Cunninghamia lanceolata and Pinus massoniana seedlings under low phosphorus stress   总被引：1，自引：0，他引：1  

Yuanchun Yu  Jian Yu  Qihua Shan  Li Fang  Defeng Jiang 《Frontiers of Forestry in China》2008,3(1):117-120

Organic acid exudation from the roots of Chinese fir (Cunninghamia lanceolata) and Masson pine (Pinus massoniana) seedlings under low phosphorus stress was studied using the solution culture method. The results revealed that organic acid exudation from the roots of Chinese fir and Masson pine seedlings under low phosphorus stress increased. Compared with P₃ (KH₂PO₄, 0.5 mmol/L), the average organic acid exudation from the root of Masson pine seedlings under P₀ (KH₂PO₄, 0 mmol/L), P₁ (KH₂PO₄, 0.03 mmol/L) and P₂ (KH₂PO₄, 0.09 mmol/L) increased by 328.6%, 267.9% and 126.4% respectively. Masson pine from Zhejiang Province in China had the highest organic acid exudation. Under low phosphorus stress, the increase in organic acid exudation from the different provinces of Chinese fir and Masson pine varied. Masson pine from Zhejiang Province mainly increased oxalic acid, tartaric acid, citric acid and malic acid exudation, that from Guangxi Province mainly increased oxalic acid and tartaric acid exudation, and that from Guizhou Province, China mainly increased oxalic acid, tartaric acid and malic acid exudation. Chinese fir mainly increased oxalic acid and tartaric acid exudation. __________ Translated from Journal of Nanjing Forestry University, 2007, 31(2): 9–12 [译自: 南京林业大学学报]  相似文献