玉竹根腐病的发生与防治

在玉竹的栽培生产中,病害大量发生,其中最为严重的是根腐病。玉竹根腐病是由镰刀菌引起的一类土传病害,近年在湖南、广东老栽培区域有逐年加重的趋势。分析其危害症状和发生特点,可对其采取合理轮作、栽培措施防治、土壤消毒、药剂防治等综合防治措施,以促进玉竹的产量和品质。     

不同化学杀菌剂对玉米茎腐病菌的抑制活性测定

为了筛选得到对玉米茎腐病菌室内抑制活性较高的杀菌剂,采用菌丝生长速率法测定了不同化学杀菌剂对肿囊腐霉菌（Pythium inflatum）和禾谷镰孢菌（Fusarium graminearum）2种致病菌的抑制活性。结果表明,丙森锌、雷多米尔·锰锌、烯酰吗啉和氟吡菌胺4种杀菌剂对肿囊腐霉菌的毒力较高,其EC50。分别为O．40μgZmL、0．47μg／mL、0．61μg／mL和2．64μg／mL;禾谷镰孢菌对咯菌腈、戊唑醇和多菌灵3种杀菌剂的敏感性较高,其EC50分别为0．06μg／,mL、0．32μg／mL和0．85μg／mL,苯醚甲环唑和腈菌唑2种杀菌剂对禾谷镰孢菌的抑制活性稍差,其EC50。分别为1．71μg／mL和1．80μg／mL。上述筛选到的9种药剂对玉米茎腐病菌的室内抑菌活性较高,可以作为供试药剂进行大田药效试验。     

不同玉米杂交种茎腐病抗性比较研究

为了筛选对茎腐病抗性较强、产量较高的玉米杂交种,采用人工接种法研究了不同玉米杂交种对茎腐病抗病性和产量结构变化。结果表明,不同玉米杂交种对茎腐病的抗性差异较大。其中,杂交种3号达中抗（MR）,其它均为感（S）或高感（HS）;接种玉米茎腐病菌的杂交种和未接种的穗长、穗粗、行粒数、单穗重、单穗粒重和百粒重之间差异显著（P〈0．05）,而对秃顶长度、粒行数的影响不显著（P〉0．05）。杂交种3号的产量最高,明显高于郑单958,是较为理想的抗病高产新组合。     

Experimental Study on Decolorization and Degradation of Reactive Brilliant Red X—3B in a White Rot Fungal Biofilm Reacor

Experimental results of an azo dye(reactive brilliant red X-3B,RBR X-3B) decolorization and degradation in a white rot fungal biofilm reactor were introduced and discussed.The fungal biofilm reactor is highly potential for dye decolorization and degradation with the highest decoloring rate of 95% within 96 hours reaction time at initial pH 4.5 under high nirogen level (HN) (24mmol/L ammonium tartrate)condition.Experimental conditions.such as nutrient nitrogen levels in reaction mixture and initial pH,significantly affected dye decolorization and degradation.Effluents from this bioilm reactor can be well treated to meet the discharging requirements by use of chemical flocculation.RBR X-3B was first absorbed onto fungal biomass and then degraded gradually,The SH-13 fungus monopolized the biofilm throughout the experiments,though the reactor was exposed to open air for 4 months.     

安徽灵璧大豆根腐病病原物的分离与鉴定

对来自安徽灵璧县虞姬乡的大豆根腐病的土壤样品进行了病原分离和鉴定。经诱捕分离,从发病田块的土壤和发病植株上共分离到3株大豆疫霉菌株;采用特异性PCR检测,结果表明分离物为大豆疫霉;生理小种测定表明,3个菌株的毒力结构与已经报道的大豆疫霉菌株不同。     

壳聚糖对菘蓝根腐病病原菌抑制作用的研究

从唐山师范学院花房中采集菘蓝根腐病病根并对其进行了病原菌的分离、纯化和鉴定及不同浓度、不同分子量的壳聚糖对菘蓝根腐病病原菌的室内抑菌作用。结果表明：分离纯化得到致病菌经鉴定为半知菌亚门（Deuteromycotina）、丝孢纲（Hyphomycetes）,丛梗孢目（Stilbellales）、瘤座孢科（Tuborculadales）、镰刀属（Fusarium）真菌。在一定浓度范围内,分子量为3KD、50KD的壳聚糖随着浓度的提高,其抑菌效果也逐渐增强,6mg／ml的效果最好;分子量为150KD时,3mg／ml的效果最好;在一定分子量范围内,除0．75mg／ml的浓度外,随着壳聚糖分子量的提高,其抑菌效果也逐渐增强,分子量150KD的效果最好;本试验中,最大抑菌率为61％。     

FTIR Measurement of Cellulose Microfibril Angle in Historic Scots Pine Wood and Its Use to Detect Fungal Decay

Microfibril angle (MFA) – the orientation of cellulose fibres in the S2 layer of the secondary cell wall – is a key determinant of the stiffness and strength of timber. The microfibril angle depends on the way in which the timber was grown and its position within the tree. Microfibril angle can be measured by X-ray diffraction and other methods, but the methods in current use are slow or require advanced instrumentation. The aim of this study was to explore the use of polarised Fourier transform infrared (FTIR) microscopy as a relatively fast and inexpensive method for measuring MFA in historic Scots pine (Pinus sylvestris L.). The FTIR measurements were calibrated against X-ray measurements of MFA in modern Scots pine. We observed a wide range in MFA values and a radial pattern of MFA similar to modern Scots pine in undecayed Scots pine heartwood from sixteenth and seventeenth century beams in Scottish secular buildings. The density of the heartwood was also similar to modern plantation-grown Scots pine despite the much slower growth rate recorded in the ring widths of the historic timber. The sapwood, which had been attacked by both insect pests and fungi, showed an erratic reduction in density and a large increase in MFA compared to the modern material. The increased sapwood MFA was attributed to selective destruction of the S2 layer of the wood cell walls by fungal decay. Using MFA measurements in conjunction with density offers the possibility to estimate the mechanical properties of sound historic pine timber, to detect fungal decay more sensitively than by density alone, and to distinguish between pest and fungal attack in a way that relates directly to the remaining mechanical performance of the timber.     

云南西双版纳香荚兰种植园土壤微生物类群初探

对采自西双版纳香荚兰11个不同种植区土样中的细菌、放线菌和真菌三大微生物类群进行了分析,分离出真菌优势种群14种、细菌31种、放线菌8种。细菌中芽胞杆菌占半数以上,放线菌中金色类群和白孢类群占优势。要从土壤的微生物区系对其病害进行调控,需要进一步摸清优势种群与病害的关系,并从中找出其有拮抗性的优势菌,分析研究诱发其有拮抗性的优势种群条件。     

《孙子兵法》与市场挑战者战略

《孙子兵法》虽然是一部古老的军事著作,但其所揭示的战略思想和战争理念却对现代企业竞争有着巨大的指导意义。市场挑战者作为市场竞争的一支重要力量,在竞争战略的准备、竞争战略制定、竞争战略的实施三阶段均可以孙子兵法为指导,吸取其精髓,以更好地实现战略目标。     

玉米新组合茎腐病抗性鉴定的分析

本试验对56个玉米新组合采用田间人工接种玉米茎腐病菌(腐霉菌)的方法进行了抗性鉴定。结果表明,B-26和BJ1-58抗性最好,达到R(抗)水平,发病率分别为5.3%和10%;有19个组合达中抗(MR)水平,发病率在15%～30%之间。