自然干旱后不同系号杨树湿心材的特征

以2017年造林材料为对象,比较不同系号杨树湿心材在大旱前和大旱后的变化差异。结果表明:干旱前和干旱后所有系号杨树的湿心材长度比例均呈显著正态分布。所有系号均存在湿心材现象,且整体上湿心材比较严重。杨树径生长由于干旱受到了严重抑制,但随着直径的增加及干旱的影响,湿心材长度比例继续增大,木芯含水率略有下降,干旱会减轻湿心材的危害。不同材料湿心材的pH差异不显著,均为弱碱性,江汉平原主栽的4个品种插干造林生长速度有一定优势,但湿心材相比带根造林更为严重一些。对连续2 a的湿心材特征进行相关分析,发现湿心材主要特征之间存在极显著正相关。

大花序桉心边材变异规律和候选基因挖掘研究

为探究大花序桉(Eucalyptus cloeziana)心材比例差异显著的不同家系间心边材变异规律,挖掘心材变异相关的候选基因,为珍贵用材树种高效培育及育种利用提供基因资源。以18 a生的2个心材比例差异显著的大花序桉家系为材料(家系1和2),各制作解析木3株,沿着树干以1 m为区间分段截取圆盘,测量东西和南北2个方向的带皮直径、去皮直径、总年轮数、边材年轮数、边材直径,并开展心材和边材径向和轴向分析。同时利用各解析木胸径处初生木质部样品进行DNA混池测序,发掘等位基因频率差异显著的SNP位点并挖掘相关功能基因。结果表明,大花序桉边材宽度和心材半径的方位变异中家系2大于家系1,平均差值分别为0.7和5.5 cm,在随树高的变异中,家系1和2的心材半径和心材年轮数的下降速率分别为0.40和0.64及0.43和0.36。两家系间基本密度差异显著,家系1为0.80~0.82 g/cm^(3),家系2为0.75~0.78 g/cm^(3)。基本密度与树高、横截面半径和心材半径呈显著负相关,与顺纹抗拉强度、弦面硬度和部分力学性质呈显著正相关。利用DNA混池测序共筛选到两家系间基因频率显著差异的SNP位点1842个,SNP注释分析表明位于基因间、上游区域、下游、外显子和内含子区域的SNP位点分别为55.8%、18.3%、16.3%、5.1%和4.4%。基因功能注释及富集分析发现SNP位点区域的基因主要与植物细胞分裂、植物细胞膜和植物蛋白激酶相关。通过大花序桉心材比例差异大的两家系间解析木径向和轴向分析,探讨了它们的心边材变异规律,结合DNA混池测序,挖掘了心材变异相关的SNP位点并筛选出一些木材形成相关候选功能基因。

醉香含笑不同树高处心边材挥发性成分的差异

为探究醉香含笑不同树高处心边材挥发性成分的积累规律及香气应用价值,利用顶空固相微萃取-气相色谱-四极杆飞行时间串联质谱法(HS-SPME-GC-QTOF-MS)对醉香含笑2个不同树高处心材、边材的挥发性成分进行非靶向代谢组学分析。采用主成分分析法(PCA)、正交偏最小二乘-判别分析法(OPLS-DA)、层次聚类分析法(HCA)分析不同树高处心边材挥发性成分差异,并鉴定差异代谢物。结果表明:醉香含笑2个不同树高心边材共鉴定出92种挥发性化合物,筛选出35个差异代谢物,其中边材中的单萜类、醛类、烷烃类化合物在边材中的合成水平显著高于心材,且随着树高的增加而积累。

江汉平原黑杨湿心材细菌微生物群落结构解析

为探究细菌微生物群落在杨树湿心材发病过程中的作用,以江汉平原6年生华石2号黑杨湿心材和正常材为研究对象,采用高通量测序对16S rRNA基因V5―V7区进行测序,对测序列结果进行信息学分析,利用主成分分析、α多样性指数分析和微生物网络分析技术等方法,探究6年生黑杨湿心材和正常材细菌微生物群落结构和组成差异。结果表明:6年生华石2号黑杨湿心材和正常材细菌微生物群落属水平上,劳尔氏菌属和拟杆菌属的细菌丰度最高,拟杆菌属、多形单胞菌属和氢孢菌属在湿心材中占比显著高于正常材(P<0.05)。微生物群落功能分析显示,劳尔氏菌属多为植物病原菌,在湿心材中广泛存在。α多样性指数分析表明,湿心材群落多样性和物种分布均匀度高于正常材,物种总数低于正常材。共现网络研究表明,黑杨正常材细菌微生物之间存在较多的竞争和拮抗作用,群落较不稳定,湿心材细菌间存在更多的协同和互生关系,微生物群落较稳定。关键微生物分析表明,6年生黑杨湿心材中关键细菌微生物是Aquabacterium、WCHB1-32等,6年生黑杨正常材中关键细菌微生物是Pleomorphomonas、Dysgonomonas,这些关键微生物在稳定湿心材微生物网络结构中发挥着重要作用。以上结果表明,黑杨湿心材形成受多方面因素的影响,是由微生物群落共同作用产生的结果。

施钙对降香黄檀心材抽提物的影响

为探究施钙对降香黄檀心材抽提物的影响,为其人工林高效培育提供参考,以6年生降香黄檀为研究对象,采用注射CaCl_(2)溶液和填埋Ca(OH)_(2)固体2种不同施钙方式,分析不同钙施加量对心材抽提物的影响。结果表明:注射CaCl_(2)溶液后,降香黄檀心材抽提率、黄酮类化合物和挥发油类化合物的含量具有明显提升,且随溶液浓度的提高,促心材抽提物效果变差;填埋Ca(OH)_(2)固体后,降香黄檀心材抽提率基本不变,黄酮类化合物和挥发油类化合物含量降低。注射CaCl_(2)溶液具有较好的促心材抽提物形成效果,以2%浓度为宜;填埋Ca(OH)_(2)固体未发现有促心材抽提物形成的效果。

毛红椿生长、心材和材性性状遗传分析及家系选择

[目的]通过研究15年生毛红椿家系试验林的生长、心材和材性性状的遗传变异规律,选择速生且优质的毛红椿优良家系。[方法]以浙江开化县林场的15年生毛红椿家系试验林为材料,测定其树高、胸径、材积、心材率、心材材积和木材基本密度,进行方差、相关和主成分等分析。[结果]毛红椿家系间树高、胸径、材积、心材率、心材材积和木材基本密度等6个生长、心材和材性性状的差异均达极显著水平,并有较高的遗传稳定性,但冠幅和枝下高在家系间差异不显著。表型相关和遗传相关分析表明,毛红椿胸径与心材材积和材积之间呈显著正相关,通过对胸径的选择能间接实现对材积和心材材积的选择。主成分分析结果显示,材积、心材材积、胸径、树高和心材率等5个性状代表了毛红椿的品质和经济性状,对前两个主成分PC1和PC2的贡献率较高。通过构建材积、心材率、心材材积和木材基本密度等4个性状的综合指数选择方程,对毛红椿所有家系进行综合评价,选出了2个符合改良条件的优良家系,其材积、心材率、心材材积和木材基本密度获得的平均遗传增益分别为:52.84%、0.49%、66.23%和2.13%。[结论]毛红椿育种目标应重点围绕生长和心材性状,而冠幅和枝下高遗传力较小且家系间差异不显著,不适宜作为遗传改良的目标。

中药远志薄层色谱及超高效液相色谱特征图谱的研究

目的建立远志薄层色谱(thin-layer chromatography,TLC)及超高效液相色谱(ultra-high performance liquid chromatography,UHPLC)特征图谱,并分析远志全根、根皮和木心间化学成分差异,为远志质量评价提供参考。方法以3,6’-二芥子酰基蔗糖、细叶远志苷A和远志皂苷B为指标成分建立TLC图谱;用UHPLC法建立远志特征图谱,结合热图聚类分析、主成分分析(principal component analysis,PCA)和正交偏最小二乘法判别分析(partial least squares discriminant analysis,OPLS-DA)评价多批远志全根、根皮和木心之间的差异性。结果TLC图谱斑点清晰、分离度较好;UHPLC特征图谱共标定28个共有峰,指认了其中的7个特征峰,13批次远志特征图谱与对照图谱相似度均大于0.9,批次间质量较为稳定;TLC和UHPLC特征图谱显示远志全根、根皮和木心化学组成一致,未发现特异成分,热图聚类分析和PCA显示远志全根与根皮中各成分峰面积接近,OPLSDA筛选出10个变量投影重要性(variable important in projection,VIP)值大于1的差异性成分。结论所建立的TLC及UHPLC特征图谱简便、准确、稳定,展开系统和提取溶剂均使用低毒试剂,符合绿色化学理念,适用于远志的质量评价,从化学分析角度说明木心的存在对远志整体化学成分影响较小。

植物生长调节剂对降香黄檀心材抽提物的影响

为探究不同生长调节剂对降香黄檀心材形成的影响,以6年生降香黄檀为研究对象,采用不同浓度的赤霉素(GA)、6-苄氨基腺嘌呤(6-BA)和吲哚乙酸(IAA)进行处理,以期为降香黄檀人工林的培育提供参考。结果表明,浓度为2%、3%、4%的GA和浓度2%、4%的6-BA和0.6%的IAA对降香黄檀心材形成有积极作用,浓度3%的6-BA和浓度为0.4%、0.8%的IAA部分指标低于对照(CK)组,浓度为0.6%的IAA处理效果最好。

邓恩桉种源幼龄材树皮率·心材率和基本密度变异

采用质量法、体积法及排水法测定了邓恩桉种源幼龄材树皮率、心材率和基本密度,结果表明:5年生邓恩桉重量树皮率、体积树皮率、心材率、基本密度分别为17.003%、15.139%、16.950%、0.484 g/cm^(3)。3个性状在不同种源间差异不显著。10个种源木材基本密度属于中等密度,满足纤维用材要求。

降香黄檀心材形成研究进展

降香黄檀是我国特有的珍贵树种,其心材应用广、用量大。然而,由于降香黄檀心材形成所需时间较长,短时间内难以产生大量心材资源,市场上出现降香黄檀心材供不应求的局面。因此,调控心材的形成成为提高降香黄檀可持续利用价值的关键。为此,介绍了心材形成机理,系统梳理了近年来关于降香黄檀心材形成过程及人工诱导的研究报道,旨在为深入研究降香黄檀心材形成机理、制定有效提高降香黄檀心材产量和质量的人工诱导策略提供参考,促进降香黄檀资源的可持续利用。

6年生黑木相思木材的生材性质研究

以6年生黑木相思为研究对象,对其木材的生材性质进行分析,为人工林黑木相思木材的合理利用提供参考。通过排水法、质量法及数值法对黑木相思的树皮率、心材率、生材含水率及木材密度进行测定,结果表明:黑木相思树皮体积分数、树皮质量分数、心材率、生材含水率、生材密度和基本密度平均值分别为15.94%,17.06%,49.53%,77.70%,0.773,0.437 g/cm3。自树干基部向上,黑木相思的树皮体积分数、树皮质量分数、基本密度总体上均呈波动性增加的趋势,心材率总体上均呈递减的趋势,生材含水率、生材密度总体上呈波动性递减的趋势;自髓心向外,黑木相思的生材含水率均逐渐降低,生材密度南北向上均呈先平稳后下降的趋势,基本密度在南北向上的变化规律有所差别,在北向上呈先下降后增加的趋势,在南向上呈逐渐增加的趋势。

装饰单板漂白染色处理的色差调控机理

装饰单板色差主要是由木材心边材木质素和抽提物含量的不同所导致的。木质素和抽提物中丰富的发色基团及助色基团使木材心材颜色加深,与边材形成明显的色差。采用漂白染色处理方法可以对装饰单板进行色差调控。为进一步分析色差调控机理,通过扫描电子显微镜(SEM)、红外光谱(FT-IR)、X射线光电子能谱(XPS)对漂白处理前后的黑胡桃单板微观结构和化学成分进行测试分析,研究木材心边材微观结构、内含物、木质素等物质中发色基团含量的变化,分析木材色度变化形成的机理。研究结果表明,漂白处理后心边材色差ΔE从11.48降至2.97,而染色处理可赋予装饰单板特定的色彩;扫描电镜、红外光谱和XPS分析结果显示,漂白处理的装饰单板导管内含物明显减少,去除了部分木材表面的脂肪酸类内含物。漂白过程中O/C值降低主要与木质素降解,以及主要的发色基团共轭CO双键被破坏导致O元素的含量降低有关。木质素所含有的共轭CO和CC发色基团产生了部分降解,这是漂白处理导致单板色度变化的主要原因。同时,木质素降解导致细胞壁产生皱缩,木材内部孔隙增多,利于染液在单板内部均匀渗透。而单板在染色过程中没有与染料发生化学结合,只是物理吸附的过程。

Brazilin from Caesalpinia sappan heartwood and its pharmacological activities:A review

Caesalpinia sappan L.(CS) is a plant of Leguminosae family,commonly known as Brazil or Sappan wood.CS is distributed in Southeast Asia and its dried heartwood has been used as traditional ingredient of food or beverages and has a wide variety of medicinal properties.Higher extraction yield of CS wood was achieved with 95% ethanol for 2 h.Chemical constituent's investigation of sappan wood resulled in the isolation of various structural types of phenolic components including one xanihone,one coumarin,three chalcones,two flavones three homoisoflavonoids and brazilin.Brazilin[(6a S-cis)-7,11b-dihydrobcnz[b]indeno[1.2-d]pyran-3.6a.9.10(6H)- tetroll.a major and active compound found in CS heartwood.Most of the folkloric uses of brazilin were validated by the scientific studies such as antioxidant,antibacterial,anti-inflammatory,anti-photoaging.hypoglycemic,vasorelaxant,hepatoproteetive and anti-acne activity.CS heartwood extract is safe and did not produce any acute or subacute toxicity in both male and female rats.Brazilin is the safe natural compound having potential to develop as a medicinal compound with application in food,beverage,cosmetics and pharmaceutical industries to screen its clinical use in modern medicine.The information gained could provide the important and potential approach for pharmaceutical researcher to implicate the knowledge of brazilin in the formulation of new drug and to reveal therapeutic and gaps requiring future research opportunities.More studies are needed to evaluate the potential application of brazilin as preservative and coloring agent in food processing industries.

Simulating the heartwood formation process of Erythrophleum fordii in South China

We studied the formation of heartwood in Ery- throphleumfordii Oliv., an endangered rosewood species, by cross-section analysis on 52 stumps aged 28-57 years and arbitrarily sampled from natural forests in South China. Width and area of heartwood were positively correlated with age and xylem width （XW）, and were independent of annual radial growth. The proportions of heartwood and sapwood areas were equal at about 40 years. The heartwood formation pro- cess was simulated by linear regression of age and XW.

Analysis of compounds in dichloromethane extractives for Sawara Falsecypress （Chamaecyparis pisifera） outer heartwood

The chemical components of dichloromethane extractives for Sawara Falsecypress heartwood were analyzed with GC/MS except for basic chemical composition analysis for heartwood with Chinese standard method. 14 kinds of compounds were idenfifjed according to the computer compounds library data. The major compounds in dichloromethane extractives comprised of terpene and naphthalene derivafives. The experiments of antifungal effects of the dichloromethane extractive on Aspergillus niger were also carded out. The result showed that the dichloromethane extractive from Sawara Falsecypress has no or weak antifungal capability.

Relative efficacy of heartwood extracts and proprietory wood preservatives as wood protectants

The relative potentials of either heartwood extracts (air dry extracts in 60 percent methanol) of very durable woods (Afzelia africana J.E. Smith; Erythrophleum suaveolens (Guill & Perr.) Brenam. Syn. E guinensis G.Don. or Milicia excelsa (Welw) C.C. Berg. Syn. Chlorophora excelsa (Welw) Benth.) or any of two proprietary wood preservatives (AWPA type 揅? Chromated Copper Arsenate (CCA) or 5 percent solution of AWPA Standard Designation P ??type 揅? Pentanchlorophenol (Penta) in light oil solvent) to suppress attack on pressure treated Antiaris toxicaria Lesch Sapwood by either any of three species of decaying fungi (Coridopsis Polyzona Klotzch; Lenzites trabea; or Trametes cingulata Fr.) under soil block exposure conditions were investigated and threshold values determined. Extract/preservative dosages were either 8.009; 24.778; 48.056; 96.111 or 144.167 kg穖-3 (0.5; 1.5; 3.0; 6.0 or 9.0 1b/ft3). Exposure was for either 14 or 28 weeks and in accordance with ASTM D1413 72 Provisions. Conclusions reached were that at threshold values the ability of either any of the heartwood extracts or proprietary wood preservatives to suppress attack under conditions in this study was significant at 0.01. Relative efficacy of those biocides was dependent on fungal species. Neither any of the heartwood extracts nor any of the proprietary wood preservatives (except in the case of Trametes cingulata attack on CCA treated wood at highest retention level) was able to confer 搗ery durable?rating on treated wood. Possible reasons for the reduced relative durability of extracts visa vis native heartwood were advanced. At the highest retention level (144.167 kg穖-3) there was no significant difference (at 0.05 level) between efficacy of each of the heartwood extracts and any of the proprietary wood preservatives (CCA or Penta).

Effect of compression on the liquid absorption of Chinese fir wood with different heartwood-to-sapwood ratios

In this study, the Chinese fir （Cunninghamia lanceolata Hook.） specimens with different ratios of heartwood thickness to sapwood thickness （HS） were radially compressed at different compression speeds, and then absorbed amine copper quat-type D （ACQ-D） preservative solution under the negative-pressure produced by the recovery of compression deformation. The liquid uptake （Al）, the recovery rate of compression deformation （Rs） and the chemical absorption （Ac） of samples were determined, as well as the overall distribution of density and effective component of ACQ-D （i.e., copper in wood）, the mechanical properties such as surface hardness were also measured. The Al, Rs, Ac values of compressed samples including the whole heartwood ones were higher than those of uncompressed samples, showing that radial compression had an obvious positive effect on improving the liquid absorption of heartwood. Higher compression speed of 3 mm.min^-1 is preferable since the samples with that speed could reach the highest Al and Ac; in addition, more deformation fixation has been produced possibly because of the faster heat and moisture transmission at the higher compressed speed, and more bonds of hydrophobic nature were formed, leading to the higher surface hardness and density. A consistent tendency of the density distribution and the copper retentions along the thickness direction could be explained that the layers with higher density have smaller volumes of void areas, and more chemicals were absorbed and fixed, resulting in the higher copper retentions.

Heartwood variations in mid-aged plantations of Erythrophleum fordii

Erythrophleum fordii Oliv.(Caesalpiniaceae)is a rosewood species naturally distributed in southeast Asia and south China,and the heartwood is commonly used for high-quality crafts and furniture.While there are differences in heartwood development among single trees with distinct social status,the relationship between heartwood development and growth performance remains unclear.This information is essential to improve plantation management for high-yield heartwood production.Forty dominant,intermediate and suppressed trees were sampled from E.fordii plantations aged in 32-35 years in Pingxiang City,Guangxi,China.Stem analysis was carried out to determine horizontal and vertical variations of heartwood and sapwood.Number of annual rings,diameter and area of heartwood and sapwood as well as ratios of heartwood diameter and area at breast height were all significantly influenced by the social status of trees in stands(P<0.05).In these mid-aged plantations,E.fordii stems developed heartwood once the xylem diameter reached 5-10 cm,and then heartwood diameter and area increased with increasing xylem diameter.Heartwood ring numbers,diameter and area as well as their ratios decreased with increasing height,while sapwood ring numbers and diameter were relatively constant within the section where heartwood occurred.Heartwood and sapwood diameters were equal at heights of approximately 6-m for dominant,5-m for intermediate and 3-m for suppressed trees.Dominant trees differed considerably from intermediate and suppressed trees in heartwood volume,while heartwood volume ratios were all below 30%,and near 90%in the stem section below 8-m height regardless of social status.Relationship analysis showed that DBH was the most important factor influencing heartwood in even-aged stands.The findings provide evidence for crop tree selection,thinning regimes and reasonable management of plantations of E.fordii.

Experimental Study on Heartwood Formation and Development of Red Sandalwood by Grafting

Red sandalwood(Pterocarpus santalinus)is the most precious species of Pterocarpus,and the long maturity period of its heartwood is an important factor limiting its development.The 1-year-old plants of P.macarocarpus were chosen as the rootstocks to graft red sandalwood with single-bud scions of 1-year-old shoots in spring.The 5-month survival rate reached over 80%,and the grafted plants grew well.Moreover,the grafting significantly promoted the formation and development of the heartwood of red sandlawood.At 18^(th)month after grafting,compared with the seedling plants,the diameter of heartwood was increased by 82.8%and 29.6%,respectively,and the ratio of heartwood increased by 64.8%and 29.6%,respectively.The propagation technology had outstanding practical value and scientific significance,which has not been reported at home and abroad.

Movement of boron from ulexite and colemanite minerals in sapwood and heartwood of Cryptomeria japonica

This study evaluated boron diff usion from raw boron minerals ulexite and colemanite with low water solubility in comparison to disodium octaborate tetrahydrate(DOT).Tests were conducted using sugi(Cryptomeria japonica(L.)f.D.Don)sapwood and heartwood blocks conditioned to 30,60,and 90%target moisture content.The blocks were fi lled with the boron compounds through treatment holes and diff usion was observed at three assay zones across the blocks after 7,30,60 or 90-day incubation period at room temperatures.For comparison,ethylene glycol was also introduced into the holes to elevate boron diff usion.As expected,diff usion increased with increased moisture content and levels were higher at the 60%and 90%moisture levels compared to the 30%level.With some exceptions,boron levels did not follow consistent gradients with distance away from the treatment hole.Incorporation of ethylene glycol helped increase boron levels,even in heartwood blocks.Boron levels were higher from the ulexite source than from colemanite;however,DOT treatments resulted in the highest boron diff usion rates as a result of greater water solubility compared to both raw boron minerals.The results suggest that ulexite together with ethylene glycol may be useful in both sapwood and heartwood materials when kept at high moisture levels for extended periods.