丛枝菌根真菌和不同形态氮对杉木幼苗根际土壤氮磷养分含量及其相关酶化学计量比的影响

目的 探究丛枝菌根真菌(AMF)和不同形态氮(NH4+-N、NO3−-N)对杉木根际土壤氮(N)与磷(P)养分含量、相关酶活性及其化学计量比的影响,为杉木人工林的可持续经营管理提供理论依据与数据支持。 方法 本研究以1年生杉木幼苗为研究对象,采用盆栽实验,研究杉木幼苗在接种摩西球囊霉(G. mosseae, Gm)和添加不同形态N(NH4+-N、NO3−-N)后根际土壤N、P养分含量及其相关酶活性与化学计量比的变化。 结果 (1)AMF接种提高了土壤有效P含量,降低了土壤中硝态氮、铵态氮、可溶性有机氮以及全P含量,与NH4+-N处理相比,NO3−-N处理下AMF对土壤N、P养分的调节作用更显著(p<0.05);(2) AMF和不同形态N添加提高了土壤中酸性磷酸酶(AP)、脲酶(URE)、N-乙酰-β-D葡萄糖苷酶(NAG)活性,其中,NH4+-N处理下AMF更有利于提高URE活性,NO3−-N处理下AMF更有利于提高NAG活性。(3)接种AMF降低了土壤URE:AP、PRO:AP以及NAG:AP的比值(p<0.05),且在NO3−-N处理下土壤URE:AP、PRO:AP的化学计量比的下降幅度高于NH4+-N处理。 结论 AMF接种通过提高土壤中氮磷相关转化酶的活性,降低氮磷转化酶的化学计量比来提高杉木土壤P有效性,促进土壤中有效N、P向植物体内的转移,维持土壤N、P平衡,且NO3−-N处理下AMF对土壤N、P平衡的调节效果强于NH4+-N处理。     

东北红豆杉内生真菌的鉴定-----新种和已知种及其代谢产物

从长白山自然保护区原始森林200多年生的东北红豆杉(TasxuscuspidateSiebetZucc.)的树皮中分离出94株内生真菌,鉴定出19种。其中,除10个新记录属种外,还包括2个新种:长线孢拟茎点(PhomopsislongiscoleosporuY.XiangetLuAnGuo,WuWenFang)和大孢盾壳霉(ConiothyriummacrospoumY.Xiang,LuAnGou,WuWenFang);1个新变种为紫杉链格孢[Alternariaalternata(Fr.)Keisslervar.taxiY.XiangetLuAnGuo];还有6个国内已知种:阿姆斯特丹散囊菌(EurotiumamstelodomiMgngin),匐散囊菌原变(EurotiumrepensdeBary),葡萄孢(Botrytissp.),桔青霉(PenicilliumcitrinumThom),黑附球孢(EpicoccumnigriumLinK),镰刀孢(Fusariumsp.)。用薄层层析技术,测定了各菌种发酵代谢产物,经筛选发现紫杉链格孢[Alternaria(Fr.)Keisslervar.taxiY.XiangetJ.X.Cui],葡萄孢(Botrytissp.),阿玛姆斯丹散囊菌(EurotiumamsteloodomiMgngin),匍匐散囊菌原变种(EurotiumrepensdeBary)4种内生真菌的代谢产物可与紫杉烷类物质显色剂——香草试液发生较明显的颜色反应,其中紫杉链格孢[Alternariaalternata(Fr.)Keisslervar.taxiY.XiangetJ.X.Cui]菌种的代谢产物中有一种含量较大的组分,还可与稀碘化铋钾生物碱试剂发生反应,该组分化合物经过光谱分析,为紫     

Comparative virulence of blue-stain fungi isolated from Japanese red pine

 We made inoculations to determine the comparative virulence of blue-stain fungi isolated from Japanese red pine (Pinus densiflora Sieb. & Zucc.). Based on the symptoms caused by each fungus, the most virulent fungus was Leptographium wingfieldii. Also, Ophiostoma minus was relatively virulent while lesions induced by some species did not differ from those in the control treatment. Based on the results, we concluded that the pathogenicity of the blue-stain fungi varied widely, and thus their impact on the host most likely varies too. Received: June 7, 2002 / Accepted: October 4, 2002 Present address: JST Domestic Research Fellow, Forest Pathology Laboratory, Tohoku Research Center, Forestry and Forest Products Research Institute, 92-25 Nabeyashiki, Shimo-Kuriyagawa, Morioka 020-0123, Japan Tel +81-19-648-3961; Fax +81-19-641-6747 e-mail: H_masu@hotmail.com Acknowledgments We thank Drs. Ohtaka and Usuki, Plant Pathology and Mycology Laboratory, Institute of Agriculture and Forestry, University of Tsukuba, for technical assistance. Contribution No. 174, Plant Pathology and Mycology Laboratory, Institute of Agriculture and Forestry, University of Tsukuba. Correspondence to:H. Masuya     

陇东子午岭林区针叶树生斑痣盘菌

陇东子午岭林区针叶树生斑痣盘菌目(Rhytisnlatales)真菌5属13种；其中寄主新记录2种，国内分布新记录7种。     

生物预处理竹子对纤维酶糖化的影响

随着石油资源短缺形势日趋严峻,燃料乙醇作为可再生的替代能源越来越受到重视,为消化大量陈化粮,我国于2001年批准了4个用陈化粮生产燃料乙醇的试点企业.但是,目前粮食燃料乙醇已经开始叫停,2007年5月,财政部制定施行的<可再生能源发展专项资金管理暂行办法>中亦未把玉米、小麦、水稻等粮食列为生产燃料乙醇的原料.     

快速检疫中培养松材线虫的冷藏真菌菌种筛选

松材线虫病是一种通过媒介昆虫携带松材线虫(Bursaphelenchus xylophilus)侵染松树而导致松树迅速死亡的一种毁灭性传染病害。人为调运未经处理或处理不彻底的感病原木、木材、薪材及包装箱等制品是病害扩散的主要原因。随着国际贸易往来和国内各地之间各种形式的交流日益频繁,     

牡丹红斑病病原菌的研究

从8批次,512个样品中分离得到的优势菌株,对其形态特征、及其着 生方式进行显微检测,同时,进行生物学特性和致病性测定。鉴定出牡丹红斑病病原为枝孢霉（Cladosporium Paeoniae Pass)。该菌在山东地区为首次报道。     

改进马尾松育苗方法的试验

对马尾松采用控制苗木密度、芽苗截根移栽和接种菌根菌等技术进行育苗试验，结果表明：苗木密度应控制在１５０株／ｍ２，芽苗截根以保留主根长度１／２为宜；采用厚环乳牛肝菌进行人工接种效果较好。     

Changes in carbohydrase activities during vegetative growth and development of fruit-bodies of Hypsizygus marmoreus grown in sawdust-based culture

Carbohydraseproduction of Hypsizygus marmoreus cultured on sawdust rice bran medium by bottle cultivation was investigated to elucidate the carbohydrase utilized as the growth substrate for the fruit-body formation of this fungus. Among the extracellular enzymes assayed, xylanase showed the highest activity. This activity greatly increased during the end of vegetative mycelial growth and fruit-body formation. Among the cellulases. CM-cellulase showed higher activity than avicelase. The activities of -1,3-glucanase, amylase, and chitinase were low. Among the intracellular enzymes, both xylanase and amylase showed higher activity levels than the other carbohydrases. In contrast, -1,3-glucanase, avicelase, and chitinase activities in mycelia were considerably lower. These results suggest that xylanase, CM-cellulase, and amylase play an important role in mycelial maturation and fruit-body growth of H. marmoreus.