苏鲁两省杨木红变、绿变和黄变的变色病害研究

为开展苏鲁两省杨木红变、绿变和黄变的变色病害研究,于2006～2011年分别对其6个县市木加工厂的杨木鲜变色进行了调查,并在实验室内对杨木的红变菌进行了接种变色实验。结果表明,杨木自然存放30天后,都会发生红变色、绿变色和黄变色,但是,红变色比绿变色和黄变色更常见,特别是其化学红变发生率可达10%以上。杨原木的红变色率占3.2%～6.6%,绿变色率占1.1%～3.3%,黄变色率占0%～2.2%。杨木单板的红变色率占4.0%～8.5%,绿变色率占0%～3.3%,黄变色率占0%～3.2%。由镰刀菌引起的新疆杨树溃疡病,其病斑下木质的红变色和黄变色的发生率分别为54.6%和11.3%,而在NL351杨树溃疡病病斑下木质的红变色和黄变色发生率分别为7.5%和3.3%。引起杨木红变色的砖红镰刀菌和接骨木镰刀菌的分离得率达45.5%。新疆杨树和NL351杨树溃疡病病斑的红变色木质部的镰刀菌分离得率为38.4%和31.5%。实验表明,接骨木镰刀菌是引起杨木变色的红变菌。本项研究首次提出了杨木鲜变色的概念。     

抑制杨木变色生防细菌的筛选及其发酵培养条件优化研究

2006 ～ 2008年,从苏鲁两省的严重变色杨木上分离筛选得到8株对杨木变色菌可可球二孢和弯孢有较强抑制作用的枯草芽孢杆菌,通过拮抗细菌的筛选,分析了该菌株的摇床液体发酵最适条件,建立了其生长曲线.结果表明,枯草芽孢杆菌B19对可可球二孢和弯孢2种变色菌的抑制效果最好,其最佳发酵条件是培养时间为46 h,pH值为6,培养温度为35℃,摇床转速为200 r/min,装液量为50 mL.在该参数下培养出的枯草芽孢杆菌B19细菌液对可可球二孢和弯孢的抑制效果最佳.     

银杏内生细菌XZNUM033的鉴定及其抗杨树变色真菌活性物质的理化性质

银杏内生细菌XZNUM 033对杨树变色真菌—可可球二孢菌具有很强的抑制活性,通过对该菌株培养液一些理化性质的测定,结果表明:培养液在pH值为7.0时,其抗可可球二孢菌活性最强,培养液对温度、光照、紫外线都具有较好的稳定性。根据银杏内生细菌XZNUM 033的菌落、菌体形态、革兰氏染色、芽孢染色、生理生化特性以及16S rRNA序列分析,初步把银杏内生细菌XZNUM 033定为解淀粉芽孢杆菌。     

低温处理接种杨球二孢菌的研究

杨树枝条经0。C—-37°C7种低温处理后接种杨球二孢菌BotryodiplodiuPopu-lea Z.K.Zhong,对溃疡病的发生没有多大影响和规律性差异.     

我国竹材变色菌和霉菌的分离与鉴定

从华北、华南和华中地区的9个省市地区采集变色发霉竹材和竹制品标本150份,分离、纯化得到117株竹材变色菌和霉菌,采用核糖体RNA基因的内转录间隔区序列的分子生物学方法结合传统的生物学特性观察,鉴定这些真菌分属于2门、2纲、4亚纲、10目、15科、22属、56种.主要变色菌和霉菌为子囊菌纲真菌,其无性型分别为木霉属、曲霉属、青霉属、镰孢属、链格孢属和球二孢属真菌.     

温致变色杨木单板浸渍工艺

以杨木单板为基体,以热敏染料、显色剂、十四醇、增感剂为木材温致变色剂,利用超声波浸渍注入木材的方法制备可逆温致变色杨木单板,研究可逆温致变色杨木单板的浸渍工艺。结果表明:影响试件变色色差(ΔE*)的主要试验因子为超声波功率,方差分析其在0.01水平下对试件ΔE*影响显著;其次为浸渍时间和浸渍温度,方差分析二者在0.01水平下对试件ΔE*影响不显著。最佳浸渍工艺为浸渍温度75.0℃、浸渍时间4.0h、超声波功率120.0W。研制成可逆温致变色杨木单板新产品,杨木单板起始变色温度为26℃,终止变色温度为32℃;温度由26℃升至32℃时,试件由蓝色变成木材本色;温度由32℃降至26℃时,试件由木材本色变成蓝色,达到室温可逆变色的效果。     

两种杨树树皮内生真菌多样性及优势种群动态变化

为了解健杨94(转基因抗虫杨94)、三倍体毛白杨2个杨树品种干部树皮内生真菌区系及其优势种群的季节变化情况,本研究利用组织分离法从2个杨树品种996块组织中分离内生真菌1 175株,健杨94和三倍体毛白杨分别分离612、563株.利用形态特征和分子生物学方法鉴定为15个属、35个分类单元,包括担子菌1个分类单元,子囊菌34个分类单元.2个杨树品种内生真菌优势种群包括链格孢、葡萄座腔菌、镰孢属真菌、间座壳属真菌等,其中,仅有链格孢、葡萄座腔菌和桑砖红镰孢是两品种共有的优势种群种类,而且优势种群会随季节变化而变化.在两品种的内生真菌中,链格孢、葡萄座腔菌是最为常见的优势种群.     

湖北省杨树湿心材发生及危害的调查研究

杨树湿心材在湖北省发生普遍，危害严重。据在湖北省嘉鱼县的调查，9个品种的病株率都达100％，胸径部位的变色直径占胸径的31．38％～64．35％；变色面积达5．49％～42．31％，严重影响杨木的生产、加工利用及其产品的质量。杨树湿心材在1a生杨苗的插穗部就已形成，此病可能从插穗的剪口或根部的伤口侵入，沿髓心扩展至主干，髓心首先遭到破坏，然后是心材的木质部变色。     

杨树上一株链格孢菌的分离、鉴定及室内防治药剂筛选

2010年以来新疆塔城地区杨树发生大面积杨树枝干病害,给杨树生产带来巨大损失。在研究俄罗斯杨枝干病害时,以5年生新疆塔城地区俄罗斯杨枝干为材料,采用组织分离法分离获得了一株链格孢属真菌,根据其菌丝及孢子形态结合ITS序列进行了菌种鉴定,因链格孢属真菌可引起多种植物病害,采用5种常用的杀菌剂对其进行室内抑菌试验。结果表明,分离获得的链格孢属真菌鉴定为链格孢菌(Alternaria alternata)。室内药剂筛选结果显示,10%多抗霉素对供试菌株毒力最强,EC50值为0. 035 1mg/m L,其他依次为80%代森锰锌、65%代森锌、50%多菌灵和70%甲基硫菌灵。     

北京市杨树人工林微生物区系分析

选取107杨、108杨和毛白杨3种杨树人工林,采用分子生物学鉴定方法对人工林中叶面、皮部和土壤中可培养的微生物的数量变化和优势种群动态变化进行分析。结果表明:细菌的数量在107杨与108杨、107杨与毛白杨之间的差异均显著,而在108杨与毛白杨之间的差异不显著;叶面、皮部和土壤的细菌数量差异均显著,107杨夏季和秋季的细菌数量占有优势地位,毛白杨冬季和春季的细菌数量占有优势地位;107杨秋季的细菌数量最高,108杨和毛白杨的较低,季节变化直接影响着细菌数量的变化,是细菌区系变化的主要影响因素;细菌的优势种群以假单胞菌和芽孢杆菌等为主;真菌的数量在107杨与108杨、107杨与毛白杨之间的差异均显著,而在108杨与毛白杨之间的差异不显著,这与细菌的变化规律相似;秋季真菌的数量与其他3季相比差异显著;季节的变化对叶面真菌数量的影响相对较大,而对皮部真菌数量的变化影响相对较小;季节变化对土壤中真菌数量的变化有显著影响,但在春季和秋季差异不大;真菌的优势种群以杨盘二孢菌和棘壳孢等为主,其中棘壳孢在杨树人工林的叶面、皮部和土壤中均占有较高比例,是杨树人工林中真菌的主要类群。     

白桦木材变色生防菌的筛选研究

木材变色病原菌易引起木材变色,使木材发生降等。笔者采用从白桦原位土壤及自身组织分离纯化的方法,寻找对白桦变色病原菌具有拮抗作用的生防菌。经过改良5点对峙试验,筛选出对白桦木材变色5种病原菌具有拮抗作用的生防菌菌株共42株,其中x18及x26对5种病原菌都具有明显的拟制效果,菌落抑菌圈半径最大达2.1 cm。     

杨树木材变色病病原菌的鉴定

杨树木材变色病已影响了我国木材工业从粗放加工型向精细加工型的发展,已给木材工业带来重大经济损失。山东杨树木材变色病主要为褐变和红变。经分离培养、纯化、接种试验,依其培养性状和形态学特征,鉴定出杨树褐变、红变变色病的病原菌分别为Lasiodiplodia theobromae和Fusarium decemcellulare。     

木材变色病对木材工业的影响

由于木材变色已给木材工业带来较大的经济损失，因此，有效地保护木材，提高它的利用率就变得更加重要。本文对由长喙壳和其他真菌引起的木材变色，变色机理，为害，对木材性质的影响，以及我国主要木材变色病的研究进行了概述。     

Predicting sapstain and degrade in fallen trees following storm damage in a Pinus radiata forest

Storm damage in production forests constitutes a major source of economic loss world wide, yet the retrieval of salvageable timber remains problematic. In particular, an inability to anticipate when sapstain and degrade will appear hampers the planning of log recovery operations. A study was conducted to monitor the deterioration of fallen trees following two winter storms causing wind and snow damage in a Pinus radiata plantation forest in the upper South Island of New Zealand. Percentage sapstain, incidence of basidiomycete decay fungi, and frequency of bark beetle infestation increased, while percentage sapwood moisture content decreased, over a period of 1 year. These changes proceeded more rapidly in fallen trees that were severed at stump height, to simulate breakage, than in those that were left partially rooted. There was little beetle activity at the time of the storms, but Arhopalus ferus (Coleoptera: Cerambycidae), and Hylastes ater, Hylurgus ligniperda and Pachycotes peregrinus (Coleoptera: Curculionidae: Scolytinae), were collected in flight traps during the following spring and summer. The predominant fungal species associated with sapstain was Diplodia pinea, while Ophiostoma piceae and Grosmannia huntii were isolated near the end of the period. The main decay fungi obtained were Phlebiopsis gigantea, Stereum sanguinolentum, and Schizophyllum commune. A generalized linear mixed model was constructed to predict the development of sapstain in fallen trees for conditions prevailing during the study after a storm at the same time of year. According to the model, a 10 m long butt log of 22 cm mid length diameter will have minimal stain (<10% of the cross sectional area affected) when cut from severed stems up to 4 months after the storm; if taken from still-rooted trees this period will extend to 1 year. However, because of large between-tree variation, economically productive log recovery will also depend on the proportion of trees that lie below an acceptable sapstain threshold. Further research is needed to determine regional and seasonal influences on the development of sapstain in fallen trees.     

Biodeteriorating agents associated with three tropical timber species

Biodeteriorating agents are major problems of wood particularly in tropical Africa. Biodeterioration is widely observed in light coloured hardwood species especially Celtis mildbraedii, Ceiba pentandra and Pterygota macrocarpa. To determine biodeteriorating agents associated with these degradable woods, logs of C. mildbraedii, C. pentandra and P. macrocarpa were left for 6 weeks at the loading bay during the dry and wet seasons of the year 2001. The surfaces of logs were assessed for stain and mould after 7, 14, 28, and 42 days of storage. Pterygota macrocarpa harboured the highest fungal population count of 60.3×103 colony-forming units (CFU) with C. mildbraedii harbouring the least at 4.2×10² CFU after a week exposure in the dry season. Fusarium solani and Penicillium citrinum were the dominant surface moulds on log ends of wood samples, while Lasiodiplodia theobromae and Ceratocystis fagacearum were the dominant sapstain fungi. Pterygota macrocarpa and C. pentandra were more susceptible to woodborers than C. mildbraedii because of the lack of true heartwood and richer store of nutrients in its wood cells.     

Comparison of bluestain fungi grown in vitro and in freshly cut pine billets

Both moulds and bluestain fungi cause serious economic losses and much research is aimed at finding environmentally and economically acceptable methods of control. Despite this, there has been little study of the growth of these fungi in freshly cut wood unaltered by drying or sterilization and which therefore resembles the substratum normally invaded under natural field conditions. Thus, the growth of six sapstain fungi was compared at 20°C in freshly cut pine billets and on three types of artificial media (MEA, TWA and Pine Sapwood agar). The fungi comprised Ceratocystis coerulescens, Leptographium wingfieldii, Ophiostoma minus, Ophiostoma piceae, Phacidium coniferarum and Sphaeropsis sapinea. The six species varied markedly in their linear growth rate on agar media. In pine billets, they extended at different rates in longitudinal, radial and tangential directions, showing different pathogenic ability and patterns of colonization. Some species appeared to be ‘xylem preferring’ while others colonized the phloem tissue more readily. The growth of C. coerulescens in pine billets was very rapid (19.4 mm/day) and on average was more than twice as fast as on MEA, suggesting it was strongly stimulated by living pine tissue. The fungi also tended to grow more slowly in logs cut between autumn and spring compared with those harvested in mid- to late summer.     

浸渍塑化杨木单板顺纹弯曲性能研究

本研究以酚醛树脂为浸渍液,杨木单板为木材试样,对经浸渍塑化处理的杨木单板进行三点弯曲试验,探索了木/竹复合层合板的组分材料--塑化杨木单板受不同压力时的顺纹弯曲弹性性能,并分析了其与塑化压力间的关系.结果表明,塑化杨木单板的静曲模量和静曲强度与塑化压力呈非线性关系.通过对杨木单板试验研究,为木材/竹材复合材料制造过程中的结构设计和生产工艺提供一定的理论依据和基本思路,并对产品的设计、组织现场生产和产品质量评估提供一定的参考.     

木材变色和变色菌的研究现状

长喙壳属真菌不仅是引起木材变色的主要真菌，而且也是重要的植物病原菌。文中对木材变色的原因、木材变色对木材性质的影响、主要变色菌的种类、寄主范围、传播媒介等作了简述。     

杨木单板及其染色后的光变色研究

以杨木单板及其染色单板为试材,使用氙光衰减仪进行辐射试验,分析这两种单板的光变色规律及影响因素,并进行耐光性能评价。结果表明:杨木单板的光变色是木材本身;染色杨木单板的光变色是染料和木材共同作用的结果,影响其光变色的主要因素是染料的品种和结构。因此,杨木单板的光变色小于染色杨木单板,而染色杨木单板中酸性蓝染色单板光变色最显著。