引起杨树湿心材的一种病原真菌—Fusarium proliferatum9Matsushima） …

在我国,杨树湿心材是是一种分布危害严重的病害。１９９５－１９９６年从湖北,山东,河北,辽宁等省及北京地区的２０多种杨树的银,干部取样,分离到一种真菌。此 在杨树的根,干部都有广泛的分布,依据其形态特征和培养形状,据Ｎｅｌｓｏｎ,Ｔ．Ｍ,《Ｆｕｓａｒｉｕｍ Ｓｐｅｃｉｅｓ》,此菌被鉴定为Ｆｕｓａｒｉｕｍ ｐｒｏｌｉｆｅｒａｔｕｍ Ｎｉｒｅｎｂｅｒｇ。     

湿心材研究进展

笔者对国内外湿心材研究进展作了全面的概述,并提出研究中存在的问题,在此基础上提出了我国杨树湿心材未来研究方向。国外对于湿心材研究对象包括多种树种,研究的内容涉及湿心材的形成、湿心材中的细菌、液体和气体、湿心材的特征和湿心材检测等方面。我国湿心材研究的广度和深度与国外存在一定差距,杨树是我国主要速生造林树种之一,今后应该加强杨树湿心材病原、抗性育种和防治等方面的研究。     

Ⅰ—69杨湿心材发生,分布及材性的研究

在湖北省嘉鱼县潘家湾，不同生条件和不同方式种植的Ⅰ－６９杨活立木及原木都有不同程度的湿心材存在。湿心材的比例与土壤水分含量有关，与种植方式和树木生长速度无关。湿心材的存在和变色由细菌活动引起，已分离和鉴定出５种病原菌，电镜观察和材性分析表明，正常材中细菌很少，纹孔膜保存完好，而湿心材的导管一射线间纹孔和管间纹孔膜几乎都被破坏。下正常材相比，湿心材的ｐＨ和酸缓冲容量高，抽提物和灰分含量较高，综纤维素     

Ⅰ-69杨湿心材发生、分布及材性的研究*

在湖北省嘉鱼县潘家湾,不同生长条件和不同方式种植的I-69杨活立木及原木都有不同程度的湿心材存在。湿心材的比例与土壤水分含量有关,与种植方式和树木生长速度无关。湿心材的存在和变色由细菌活动引起,已分离和鉴定出5种病原菌(Erwinia carotovora Subsp.carotovora,E.rhapontioi (Millard)Burkhold,E.chrysanthemi Burkholder,Bacilluscereus Frankland,B.sphaericus Neide)。电镜观察和材性分析表明,正常材中细菌很少,纹孔膜保存完好,而湿心材的导管-射线间纹孔和管间纹孔膜几乎都被破坏。与正常材相比,湿心材的pH和酸缓冲容量高,抽提物和灰分含量较高,综纤维素和α-纤维素含量略低。湿心材的密度、干缩系数及力学性质都比正常材低,差异极显著。建议进一步研究如何防止细菌的侵入和活动,阻止湿心材和变色材的发生。     

宁夏地区光肩星天牛天敌种类调查初报

在宁夏地区光肩星天牛Ａｎｏｐｌｏｐｈｏｒａｇｌａｂｒｉｐｅｎｎｉｓ（Ｍｏｔｓｃｈ．）的天敌主要有：花绒穴甲ＤａｓｔａｒｃｕｓｈｅｌｏｐｈＯｒｏｉｄｅｓ（Ｆａｉｒｍａｉｒｅ）、赤腹茧蜂Ｉｐｈｉａｕｌａｘｉｍｐｏｓｔｅｒ（Ｓｃｏｐｏｌｉ）、草地铺道蚁Ｔｅｔｒａｍｏｒｉｕｍｃａｅｓｐｉｔｕｍ（Ｌ．）、膜毛绥螨ＬａｓｉｏｓｅｉｕｓｏｍｅｔｅｓＢｅｒｌｅｓｅ、毛绥螨Ｌ．ｓｐ．、蛾肛厉螨ＰｒｏｃｔｏｌａｅｌａｐｓｃｏｓｓｉＭｕｌｅｒ、枝厉螨Ｄｅｎｄｒｏｌａｅｌａｐｓｓｐ．     

蒸汽爆破后毛果冷杉湿心材的渗透性分析

测定毛果冷杉湿心材经蒸汽爆破处理后的渗透性, 并进行扫描电镜分析.与对照材相比,毛果冷杉湿心材爆破处理后,径向、弦向的气体渗透性均得到不同程度的改善,且随着爆破压力、爆破温度和爆破循环次数的增加而增加.统计分析表明,不同爆破处理后的湿心材渗透性与对照材的差异均显著.湿心材渗透性的改善,主要是由于蒸汽爆破时产生的蒸汽压力使原本闭塞的纹孔膜产生了部分复位或纹孔膜遭到了破坏.     

树脂溃疡病菌（镰孢菌）侵染展叶松和湿地松的感病性

树脂溃疡病菌（镰孢菌）侵染展叶松和湿地松的感病性树脂溃疡病菌（镰孢菌）Ｆｕｓａｒｉｕｍｓｕｂｇ－ｌｕｔｉｎａｎｓｆ．ｓｐ．ｐｉｎｉ（简称ＦＳＰ）在南非森林苗圃引起展叶松Ｐｉｎｕｓｐａｔｕｌａ苗木的树脂溃疡病，但在大的松树上还未见有这种症状。用ＦＳＰ接...     

宁夏地区光肩星天牛天敌种类调查初报

在宁夏地区光肩星天牛Ａｎｏｐｌｏｐｈｏｒａ ｇｌａｂｒｉｐｅｎｎｉｓ （Ｍｏｔｓｃｈ．）的天敌主要有：花绒穴甲Ｄａｓｔａｒｃｕｓ ｈｅｌｏｐｈｏｒｏｉｄｅｓ（Ｆａｉｒｍａｉｒｅ）、赤腹茧蜂Ｉｐｈｉａｕｌａｘ ｉｍｐｏｓｔｅｒ（Ｓｃｏｐｏｌｉ）、草地铺道蚁Ｔｅｔｒａｍｏｒｉｕｍ ｃａｅｓｐｉｔｕｍ （Ｌ．）、膜毛绥螨Ｌａｓｉｏｓｅｉｕｓ ｏｍｅｔｅｓ Ｂｅｒｌｅｓｅ、毛绥螨Ｌ．ｓｐ．，蠹蛾肛厉螨Ｄｅ     

低分子量MF树脂固定杨木压缩木回弹技术的初步研究

增加木材硬度和体积稳定性的方法主要包括化学改性、压缩处理和热处理。本研究使用不同浓度的水溶性低量三聚氰胺－甲醛（ＭＦ）树脂处理大青杨（Ｐｏｐｕｌｕｓ ｕｓｓｕｒｉｅｎｓｉｓ）木材，并在加热过程中作横纹方向的压缩处理，其实验结果表明：经低分子量ＭＦ树脂处理的木材试件，抗胀（缩）率（ＡＳＥ）为４７％，阻湿率（ＭＥＥ）为３６％；１０％树脂浓度处理的试件的室温条件浸水可完全保持其压缩变形；１７．５％和２５     

国外对杨树湿心材的研究

杨树是我国主要速生造林树种之一。杨树的利用对我国林业和林产工业的发展有重要影响。湿心材是树木生长中的一种反常现象,在杨树中表现甚为突出,是杨树加工利用中的一大难题。国外对湿心材的研究于上世纪初即已开始,已取得许多研究成果。本文扼要介绍国外研究的进展和一些重要观点,涉及湿心材的形成,湿心材中的细菌、气体和水分,湿心材的酸度、材色、力学强度、渗透性和湿心材对干燥、人造板生产和刨削等工艺过程的影响。     

红树林内生真菌1403的形态与分子鉴定(英文)

红树林内生真菌1403是从中国南海分离的一株镰刀菌,在液体发酵条件下能够产生灰黄霉素和葸醌类的抗生素。基于1403在形态学方面具有以下特征:产小型分生孢子的分生孢子梗较长,小型分生孢子呈椭圆形,大型分生孢子线形或略微弯曲,本文将它与有类似形态特征的镰刀菌进行了比较,发现1403与植物病原菌Fusarium verticillioides(有性态为Gibberella moniliforme)表面上很相似,气生菌丝均可产生大量假头状或链状的小型分生孢子,但深入的研究却发现1403与F.verticillioides具有不同的性状,如产生的多生分生孢子梗有时与单生分生孢子梗长度相当,产生环状菌丝,以及菌丝发生融合等现象,进一步以最大简约法和贝叶斯分析法将1403与其它相似镰刀菌进行系统发育比较,综合18S、28S、ITS三水平上的分析结果可以将1403归于镰刀菌亚组Gibberella fujikuroi,并最终在EF—1α水平上将其定为Fusarium proliferatum.     

Vibrational properties of wetwood of todomatsu (<Emphasis Type="Italic">Abies sachalinensis</Emphasis>) at high temperature

The object of this study was to understand precisely the drying characteristics of wetwood of todomatsu (Abies sachalinensis Mast.). For this purpose, the vibrational properties of wetwood of todomatsu at high temperature were compared with those of normal parts that had lower green moisture content than the wetwood. Specimens were cut respectively from the wetwood and normal parts, and matched in the radial direction. The specimens and the measuring systems were placed in an electric drying oven and free-free vibration tests were conducted in the oven under absolutely dry conditions. The wetwood and the normal parts were tested separately. The temperature was raised from room temperature to 200°C and then lowered to 50°C in steps of 25°C. The specific Young’s modulus decreased with an increase in temperature during the heating process while it increased with the decreasing temperature during the cooling process. There was no significant difference in the specific Young’s modulus between the wetwood and the normal part at all tested temperatures. The loss tangent took a minimum value at about 100°C in both the heating and cooling processes. There was no significant difference in the loss tangent between the wetwood and the normal part. Thus, the elastic and viscoelastic behaviors of the wetwood appear to be similar to those of the normal part in the temperature range of an actual kiln-drying process.     

洞庭湖区美洲黑杨湿心材化学特性及遗传变异

对洞庭湖区12个美洲黑杨品种的木材化学组分和湿心材比例及其遗传变异进行分析.结果表明:美洲黑杨湿心材中的灰分、1％氢氧化钠抽出物等化学特性均高于正常材;对他们进行相关分析表明,湿心材比例与胸径、灰分含量、酸不溶木素含量和多戊糖含量呈不显著负相关,与1％氢氧化钠抽出物含量呈不显著正相关;12个美洲黑杨品种间湿心材比例在0...     

湖北省杨树湿心材的初步研究

为了科学防治杨树湿心材,本研究对湖北省不同品种、年龄、栽植密度及立地条件的杨树湿心材发生情况和致病微生物开展了初步研究.结果表明：湖北省杨树湿心材发生十分严重,湿心材严重程度除了受到遗传控制外,还受到立地、气候等环境条件协同影响.湿心材成因复杂,杨树自身生理因素、病原微生物及外界环境均对杨树湿心材形成有影响.     

Detection of wetwood in living poplar trees by electrical resistance measurements

Wetwood was detected in living trees by determining the electrical resistance patterns across the stem with a Shigometer. The resistance of wetwood to a pulsed electric current was low compared with that of healthy sapwood. Bacteria were isolated from wood with low resistance, but rarely from wood with high resistance. Provided that drilling and measurements were performed in a stepwise fashion, the extent of wetwood could be assessed with little damage to the trees tested. This procedure may be useful in identifying trees containing wetwood, particularly in the early stages before crown symptoms become apparent.     

Der pH-Wert und das Vorkommen niedermolekularer Fettsäuren im Naßkern der Buche (Fagus sylvatica L.)

The pH-value and the occurrence of fatty acids in wetwood of European Beech (Fagus sylvatica L.). At the border of the wetwood area pH-value of the capillary liquid was altered from acid to neutral conditions. Fatty acids frequently occurred in wetwood. Probes with pH-values higher than 6.8 often were deeply black stained.     

毛白杨无性系湿心材比例的遗传分析

对毛白杨无性系测定林分内25个无性系150棵单株木芯试样的湿心材比例进行测定和遗传分析。结果表明:无性系间湿心材比例差异达到5%显著水平,湿心材比例的无性系重复力高达0.749,受中度遗传控制,在无性系间进行可获得良好效果;湿心材比例与木质素含量及与木材基本密度之间无相关性,对这3个性状可以进行单独选择;湿心材比例与胸径之间在1%水平上呈极显著的负表型相关性和显著的负遗传相关性,可联合选择;在所研究的25个无性系中,可选择1232#无性系,它的湿心材比例较低、木质素含量较低、材色较白,且胸径较大。     

The characterization of wetwood in western hemlock

Summary One of the problem areas in the kiln drying of western hemlock lumber is the wide variation in final moisture content of the wood. This variation in moisture content is due to the presence of sinker or wetwood in the heartwood. The features of wetwood which differentiate it from the normal heartwood include higher specific gravity, higher extractives content, and lower permeability. The apparent higher specific gravity can be fully accounted for by the higher extractives content. The principial extractive is α-conidendrin. The wetwood in western hemlock often occurs together with ring shake and under these circumstances the white deposit on the shake surfaces is also α-conidendrin and not matairesinol, the substance usually associated with ring shake in western hemlock. A viewpoint is presented on the origin of wetwood as the endproduct of a reaction by the tree to injury, i.e., ring shake, in which additional extractives are deposited. The extractives result in a greatly lowered permeability, which prevents loss of moisture during heartwood formation and thereby resulting in wetwood. Bacteria usually found in wetwood and responsible for many of the symptoms associated with wetwood are a result of the high moisture content which favors bacterial growth in wood. Presumably, the two primary sources of loss in kiln drying of western hemlock, shake and wetwood, are often intimately associated. The authors appreciate the assistance of Allen H. Doerksen and Louis W. Hamlin of the Forest Research Laboratory. All samples collected for this study were donated by Willamette Industries, Inc., Dallas, Oregon, and a portion of the research was supported by the Forest Research Laboratory, Oregon State University.     

Wetwood formation as a host response in white fir

A bacterium associated with wetwood of white fir did not cause wetwood in inoculated trees, and wetwood formed while external water was excluded. Wetwood formed in response to various injuries, suggesting that it is a host response to parenchyma death.