核盘菌arom基因的克隆与序列分析

本文用反向 PCR 方法扩增并分析了核盘菌 arom 基因,以研究核盘菌和其他真菌在该基因之间的进化关系,并为其编码蛋白(AROM)的催化机制研究、植物转基因和蛋白抑制剂设计提供基础。arom基因编码预分支酸芳香族氨基酸(苯丙氨酸、酪氨酸和色氨酸)合成途径中催化第二步到第六步的五功能多肽。序列分析表明核盘菌 arom 基因含有一个4773bp 的编码框,无内含子。推测的蛋白序列含有 1590 个氨基酸,与已知的所有 AROM 蛋白同源。理论分子量(Mw)和等电点(pI)分别是 172658.78D 和 6.45。核盘菌 arom 基因的GC%是 44.94%。根据搜索二级数据库 CDD 和 Prosite 的结果表明该 AROM 蛋白含有五个保守结构域:脱氢奎尼酸合成酶结构域、脱氢奎尼酸脱水酶(脱氢奎尼酸酶)结构域、莽草酸脱氢酶结构域、莽草酸激酶结构域、5 -烯醇丙酮酰莽草酸-3-磷酸合成酶(EPSP 合成酶)结构域和四个模式:两个 EPSP合成酶模式、Ⅰ型脱氢奎尼酸酶活性位点模式和莽草酸激酶模式。通过比对和参照 PIR 数据库显著位点规则发现核盘菌AROM 蛋白含有四个保守碱基。在基因 5′非翻译区-23 和-77位置分别存在 TATA 盒和 CAAT 盒。在基因下游发现有两个位点可能是 polyA 加尾信号。另外还分析了 arom 基因的系统发育。图 5 参 13。     

Influence of host on behavior ofSclerotinia sclerotiorum

All these hosts became less susceptible as the plants matures. Ascospores were unable to infect linseed leaves in the absence of an exogenous nutrient base. Even though sucrose could be used as an exogenous nutrient to stimulate the ascospores to germinate, the ascospores subsequently failed to infect undamaged linseed leaves. Linseed flower petals were an effective nutrient base which stimulated ascospores to germinate as well as to infect undamaged linseed leaves. (Responsible: Editor: Sun Yueqi).     

Cloning and sequence analysis of atom gene from Sclerotimia sclerotiorum

An atom gene was cloned from genomic DNA of Scleortinia sclerotiorum by inverse PCR. The evolutionary relationships of S. sclerotiorum and other fungi in atom gene were studied. Results showed that the atom gene from of S. sclerotiorum has a single open reading frame of 4 773 bp and does not include any introns. The derived amino acid sequence consists of 1 590 residues, and it is homologous to all fungal AROM proteins studied so far. The theoretical isoelectric point （pl） and molecular weight （Mw） is 6.5 and 172.66 kD, respectively GC percentage of the arom gene is 44.94. According to the results of searching from CDD and Prosite database, AROM protein of S. sclerotiorum contains five conserve domains： 3-dehydroquinate synthase domain, 3-dehydroquinate dehydratase （3-dehydroquinase） domain, shikimate 5-dehydrogenase domain, shikimate kinase domain, and -enolpyruvylshikimate-3-phosphate synthase （EPSP sythase） domain, and four motifs： two EPSP synthase signatures, dehydroquinase class I active site, shikimate kinase signature. According to the PIR Site Rule PIRSR000514-1, four functionally important amino acid residues are found by alignment. Putative TATA box and CAAT box locate separately in -23 and -77 loci in 5＇ un-translated region, and two loci found in downstream atom gene are likely polyadenylation signals. In addition, phylogeny of atom gene is analyzed.     

RESISTANCE OF SCLEROTINIA SCLEROTIORUM TO CARBENDAZIM Ⅰ. Resistance and Its Development of Sclerotina Sclerotiorum to Carbendazim

INTRoDUCTIoNS.sclerotiorumissensitivetomanyfungicidalchemicals-Ofthesechemicals,carbendazimwasreportedtocontrolthediseaseofdifferentplantscausedbyS.sclerotiorumtl'2'3'43.However,likemostagrochemica1s,thisfungcideisfacingthechalIengeofre-sistance,especiallybecauseitisasystemicfungicide.AccordingtotheinvestigationofDelenandYildiz(l982),sinceintensivesprayingwithcarbendazim,threecucum-beriso1atesofS.scl`,rotiorumhavea1readydeve1opedresistance(althoughitisnotveryhigh)tothefungicide.theseiso1…     

Resistance ofSclerotinia sclerotiorum to carbendazim

This paper covers the examination of EC₅₀ of carbendazim to diferent isolates ofS. sclerotiorum, the observation of the resistance development in a population of the pathogen, for working out whether carbendazim plays some role in increasing the resistance of the fungus to the chemical.     

Resistance ofSclerotinia sclerotiorum to carbendazim

This study covers the observation of the factors which influence the resistance development ofS. sclerotiorum to carbendazim, the comparison betweeen normal course of infection and infection of hosts by a strain ofS. sclerotiorum when resistance to carbendazim has been developed.     

Synthesis of N-substituted dimethylmaleimides and their antifungal activities against Sclerotinia sclerotiorum

Compounds with maleimide, both natural and synthesized, have good biological activities, especially the antifungal activity. In order to investigate the antifungal activity of dimethylmaleimides, 17 N-substituted dimethylmaleimides were prepared from the reactions of 2,3-dimethyl maleic anhydride and amines using a facile synthetic method in this paper. These compounds were evaluated for antifungal activities against Sclerotinia sclerotiorum by the mycelium growth rate method. They exhibited minimum inhibitory concentrations (MICs) ranging from 0.01–50.0 μg/mL, with N-(2-benzimidazole)-3,4-dimethylmaleimide being the most active one with an MIC of 0.01 μg/mL. The structure and activity relationship on these compounds indicated that the hydrophobicity of the N-substituents is associated with their antifungal activity. Compared to current antifungals, most of N-substituted dimethylmaleimides have a perfect activity for S. sclerotiorum control and low toxicity.     

山楂叶螨对不同寄主植物的选择性与挥发性物质的关系

山楂叶螨(Tetranychusviennenis)是仁果类和核果类果树的主要害螨之一。该螨在我国分布广泛,其寄主主要有:苹果(Maluspumila)、梨(Pyrusbretschneideri)、桃(Amygdaluspersica)、杏(Armeniacavulgaris)、山楂(Crataeguspinnatifida)、海棠(Malusspectabilis)、樱桃(Cerasuspseu     

Molecular and biochemical characterization of Sclerotinia sclerotiorum laboratory mutants resistant to dicarboximide and phenylpyrrole fungicides

Sclerotinia sclerotiorum is a necrotrophic, phytopathogenic, filamentous ascomycete with a broad host range and a worldwide distribution. Application of fungicides is the principal tool for controlling Sclerotinia diseases on most crops. Unfortunately, the extensive use of a single fungicide selects for resistant populations and leads to control failures. The phenylpyrrole fungicide fludioxonil has been reported to have high activity against S. sclerotiorum and to control Sclerotinia stem rot in rapeseed. In this study, biochemical characteristics of laboratory-induced mutants of S. sclerotiorum were determined. The results indicated that the fludioxonil-resistant mutants were sensitive to osmotic stress (high sugar). Compared to the wild-type strains, the fludioxonil-resistant mutants had a significant increase in cell membrane permeability, glycerol and oxalate content, and phenylalanine ammonia-lyase and peroxidase activity, but did not differ in exopolysaccharide content. Sequencing indicated that three wild-type strains were identical, and the mutants SZ45R and HA61R had a single point mutation while NT18R had both a single point mutation and a frameshift in the amino acid sequence coded by the two-component histidine kinase gene (Shk1, SS1G_12694). Therefore, we concluded that the biological differences between the resistant mutants and the wild-type strains may be related to mutation in Shk1. The information will increase our understanding of the resistance mechanism of S. sclerotiorum to fludioxonil and could provide new reference data for the management of Sclerotinia stem rot caused by S. sclerotiorum.     

倍子树单宁含量的分析研究

本文采用紫外分光光度法分析研究了黄连木、盐肤木６个部位及红麸杨叶片的单宁含量。结果表明,红麸杨叶片的单宁含量高达２２．３７％,高于黄连木和盐肤木的各个部位,具有一定的开发利用价值。     

薇甘菊叶斑病病原菌鉴定及寄主范围测定

对薇甘菊(Mikania micrantha)叶斑病进行分离鉴定,观察病原菌形态及进行分子生物学检测,测定病原菌生长适温及寄主范围.形态学结合分子生物学鉴定薇甘菊叶斑病病原菌为大豆茎点霉Boeremia exigua,27?℃为该菌菌丝生长最适温度,初步发现该菌可侵染桑树,不侵染其他参试作物.     

小蠹科害虫化学信息物质及其对侵害寄主等行为的影响

在综合大量国内外研究成果的基础上,就松树寄主气味、非寄主气味、小蠹虫信息素以及其他化学信息物质对调控小蠹科害虫侵袭寄主林木等的行为,作了系统详细的论述。     

不同采伐强度对森林土壤温度影响的探讨

选择多大的采伐强度对森林的经营起着关键性的作用。本文选择三种不同的采伐强度，分别在旱季和雨季进行试验，通过对土壤温度变化分析和对地表温差影响的分析，得出了若干关于采伐强度对土壤温度影响的结论，并结合林业实际提出一些建议。     

浅谈园林在城市中的应用与影响

文章就园林在城市中的应用与影响,提出了一些看法。     

生态旅游对自然保护区的影响及游客管理对策分析

世界上许多国家的自然保护区都在积极地发展生态旅游,但同时旅游也给自然保护区的生态资源环境带来了压力。本文分析了发展生态旅游对保护区内生态资源的影响和旅游者本身受到的影响,并为管理者提供了可以指导决策的框架和各种具体的管理办法。     

林木外生菌根作用及其机理综述

对林木外生菌根促进植物生长和固氮,增强植物抗病性、抗旱性和对不利环境的适应性等作用及其机理进行了综述.     

松香加氢反应影响因素探讨

通过总结大量实际生产数据，对影响松香加氢反应的主要因素——催化剂、反应温度、反应压力、进料量以及气液比等，逐一探讨分析。实际生产中企业应根据客户对产品质量要求、生产成本、经济效益等指标，综合选择一个最佳的匹配方案，以获取最大经济效益。     

Host plant range and biology of Lixus nordmanni Hochhuth (Coleoptera, Curculionidae) on hogweed Heracleum L. in eastern Turkey

The biology and host plant range of Lixus nordmanni Hochhuth were studied in the eastern part of Turkey. This weevil feeds and grows on Heracleum trachyloma Fisch. et C.A. Mey, Heracleum sosnowskyi Manden, Heracleum pastinacifolium C. Koch, H. platytaenium Boiss., Angelica sylvestris L. and Falcaria sp. of the family Apiaceae (=Umbellifera). In the early spring, adults emerged from overwintering places and started feeding on host plants. After feeding for several days on leaves, they mated and laid eggs on the main stem of a host. After emergence, larvae fed in stems up to late summer and pupated in the same places. Pupae were found at the beginning of autumn and then adults of the new generation emerged from the stem. Most of adults overwinter under dry plants at rootneck and under stones. L. nordmanni have one generation per year in eastern Anatolia. This Caucasian weevil species is recorded for the first time for Turkish fauna. The biology and host plant records are presented.     

立地条件对华木莲人工林的影响

主要探索不同立地条件对华木莲人工造林的影响。     

水泥混凝土路面断板的影响因素分析

水泥混凝土断板控制的好坏直接影响到道路的使用年限.本文详细阐述了水泥混凝土路面断板的影响因素,指出水泥混凝土路面断板既有施工控制原因,也存在自然环境、设计、养护等方面原因.针对各影响因素采取有效技术和防范措施,降低水泥混凝土路面断板现象发生.