首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Inclusion of Alternaria alternata conidia in a spray formulation affected the distribution pattern on the target. The dry weight of Amaranthus retroflexus plants was reduced by more than 83% when A. alternata conidia (107 ml -1 ) were applied at 200 L ha -1 or greater and when given a 24 h dew period. At low application volumes (25 or 50 L ha -1 ) plant dry weight was reduced by only 29 or 54%. After 7-8 h dew period, conidial germination on the leaf surface was 11-19%. This increased to 62-91% after 24 h dew period. Counts of conidia on leaves indicated that up to 86% of the conidia sprayed were not retained on the target plant, or did not reach it. This is reflected in lesion numbers per unit area being only 3-5% of the calculated theoretical numbers. The results cast doubt on the suitability of A. alternata as a microbial herbicide for the control of Am. retroflexus .  相似文献   

2.
Alternaria alternata Pesta (gluten matrix) granules stored at 12% relative humidity were still viable and infective, giving total control of Amaranthus retroflexus after 24 months storage. Viability of the propagule in the granule was an important factor of the evaluation test and not just the viability of the granule. The concentration of inoculum in the granule was important, with 10 5 to 10 6 conidia g -1 being the ideal, since lower concentrations may not be able to out-compete the soil micro-flora. Even with soil application, the effect of local humidity was still important. Trematophoma lignicola was also formulated as microbial herbicide granules but the conidia were severely damaged in the production process.  相似文献   

3.
研究了酱油曲霉(Aspergillus sojae)产生的微生物絮凝剂(MBF)的稳定性, 并将其用于城市污水厂的浓缩污泥的强化脱水。结果表明:由酱油曲霉提取的MBF具有很好的热稳定性和酸碱稳定性, 4℃低温条件下保存35 d后絮凝率仍在96%以上, 而常温条件下保存35 d后不同pH的MBF絮凝率差别很大。与PAM、PAC相比较, MBF能更好地降低城市污水处理厂浓缩污泥比阻。MBF对浓缩污泥的强化脱水的最佳投加量为7%(V/V), 且MBF的单耗随着污泥处理量的增大而逐渐减小。  相似文献   

4.
研究了酱油曲霉(Aspergillus sojae)产生的微生物絮凝剂(MBF)的稳定性,并将其用于城市污水厂的浓缩污泥的强化脱水.结果表明:由酱油曲霉提取的MBF具有很好的热稳定性和酸碱稳定性,4℃低温条件下保存35d后絮凝率仍在96%以上,而常温条件下保存35d后不同pH的MBF絮凝率差别很大.与PAM、PAC相比较,MBF能更好地降低城市污水处理厂浓缩污泥比阻.MBF对浓缩污泥的强化脱水的最佳投加量为7%(v/v),且MBF的单耗随着污泥处理量的增大而逐渐减小.  相似文献   

5.
优秀的多媒体辅助教学课件运用于课堂教学,可以激发学生学习兴趣,渲染教学氛围,构设特定的教学情境,从而有效地突破教学的重点、难点,收到事半功倍的效果。介绍了高职微生物应用技术课件制作选取的教学内容、课件教学设计思路以及课件的特色和创新。  相似文献   

6.
陈文青  邓子新 《微生物学通报》2016,43(10):2294-2297
微生物药物学是针对生命科学相关专业所开设的一门主干选修课。在生物技术高速发展的今天,如何有效建立合理的微生物药物学课程教学体系是教学工作者值得深思的课题。本文从微生物药物学教学内容及教学理念方面入手,简要阐述了作者对微生物药物学课程教学改革和实践所进行的一些有益的尝试和探索。  相似文献   

7.
新疆一号冰川土壤细菌多样性的研究   总被引:6,自引:0,他引:6  
应用变性梯度凝胶电泳(DGGE)技术分离PCR扩增的16SrDNA来研究土壤微生物的多样性。直接从新疆一号冰川不同海拔高度的土壤样品中提取总DNA。用两套细菌通用引物分别扩增16SrDNA的V3和V6/V9高变区的特异性片段,PCR产物进行DGGE分析。PCR—DGGE图谱表明,PCR产物经DGGE检测到的条带清晰且分离效果好。结果表明,PCR—DGGE是一种快速研究微生物群落结构的有效方法。  相似文献   

8.
DGGE/TGGE技术及其在微生物分子生态学中的应用   总被引:48,自引:1,他引:48  
变性梯度凝胶电泳(DGGE)和温度梯度凝胶电泳(TGGE)是近些年微生物分子生态学研究中的热点技术之一。由于DGGE/TGGE技术具有可靠性强、重现性高、方便快捷等优点,被广泛地应用于微生物群落多样性和动态性分析。文章对DGGE/TGGE技术原理与关键环节、局限性和应用前景进行了综述。  相似文献   

9.
综合应用ITS及16SrDNA进行环境微生物生态研究   总被引:3,自引:0,他引:3  
提出并介绍一种研究微生物生态的新方法.该方法将克隆测序和RISA图谱技术有机结合.其技术关键是PCR扩增的目标片段包含全长ITS和部分16S rDNA片段,既可利用16S rDNA进行系统发育分析,又可测定ITS片段大小并与RISA图谱进行比对定位.分析过程简单经济,易于操作,普通分子生物实验室即可实现.  相似文献   

10.
The influence of sampling variables on the concentration of the dopamine metabolites 3-methoxytyramine (3MT), dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) was examined in equine urine. A logarithmic transformation of the data for all horses gave distribution which approximated the normal distributions for each metabolite. The mean urinary concentration of 3 MT in horses was 214 ng/mL and the application of a threshold with a probability of 1 in 10,000 gave an actionable level of 4 microg/mL. Environmental variables were not forensically significant in determining the population distribution. HVA was not found to be a reliable indicator of dopamine or levodopa administration.  相似文献   

11.
从油井产出水中分离得到一株兼性厌氧芽孢杆菌TP-1,该菌株可在55℃的油藏温度生长,并代谢产生粘性多糖和气体.经培养条件优化,发酵液多糖产量可达5.5 g/L,产气量为22 mL/L.低浓度的CaCl2、MgSO4和AlCl3对多糖的生成有促进作用.岩芯模拟试验表明,该菌的注入可使岩芯压力增加,提高石油采收率7.37%.TP-1是一株性能良好的油藏调剖菌.  相似文献   

12.
从油井产出水中分离得到一株兼性厌氧芽孢杆菌TP-1, 该菌株可在55℃的油藏温度生长, 并代谢产生粘性多糖和气体。经培养条件优化, 发酵液多糖产量可达5.5 g/L, 产气量为22 mL/L。低浓度的CaCl2、MgSO4和AlCl3对多糖的生成有促进作用。岩芯模拟试验表明, 该菌的注入可使岩芯压力增加, 提高石油采收率7.37%。TP-1是一株性能良好的油藏调剖菌。  相似文献   

13.
异常球菌属的分类及应用研究进展   总被引:2,自引:0,他引:2  
异常球菌属的菌株是一类对引起细胞致死效应的辐射有极强抵抗能力的细菌,这类菌株不形成内生孢子,细胞呈球形或杆状,不具运动性。1956年,Anderson从经过射线灭菌处理后的肉罐头中发现了第一个异常球菌属的菌株(Deinococcus radiodurans)R1,该菌已得到了较为广泛的研究,以期阐明其抗辐射机制。伴随着微生物分类技术的发展,异常球菌属菌株的分类地位经历了很大的变化。目前,该属已涵盖了20个有效发表种。也由于异常球菌属菌株耐受辐射的能力是大肠杆菌忍耐辐射能力的千倍之上,而使其应用研究受到了广泛关注。  相似文献   

14.
对小麦杂种后代进行了约束选择,以无约束选择、单项选择为对照。试验结果表明:约束选择对选择性状的促进和约束性状的控制都有较好的效果。一对正相关的性状被约束者可保持在原平均数稍高水平;负相关的约束者则保持在原平均数略低水平。在对产量的选择中,约束选择的实际效果一般比无约束的为好,其中以约束株高选择产量的效果最佳。最后对约束选择的应用问题作了讨论。  相似文献   

15.
MAR-FISH技术及其在环境微生物群落与功能研究中的应用   总被引:3,自引:0,他引:3  
对复杂环境中微生物群落结构和功能的研究是微生物生态学的重要任务。尽管现代分子生物学技术已经成功地用于解析环境中微生物的群落结构, 但是这些方法并不能提供微生物的原位生理学信息。而一种新的方法, 微观放射自显影和荧光原位杂交集成技术(MAR-FISH)则能够同时在单细胞水平上, 检测复杂环境中微生物的系统发育信息及其生理特性。本文总结了MAR-FISH方法的原理, 实验步骤及其在环境微生物群落与功能研究中的应用。  相似文献   

16.
植物微生物生态学是研究植物微生态系统的一门学科,以植物组织细胞内微生物的组成、功能、演替,以及微生物之间和微生物与宿主之间的相互作用关系为研究对象。现代生物化学与分子生物学技术在植物微生物生态学研究领域的作用日益明显。介绍了上述技术及其在植物微生物生态学研究领域的应用进展,并对其在该领域的利用和发展进行了展望。  相似文献   

17.
Seventeen composts from separately collected organic household waste plus one bark compost and one compost from grape marc were analysed for suppression of Pythium ultimum, phytotoxicity, microbial biomass and activity, substrate-induced respiration, extractible phenolic compounds and other physical and chemical parameters. Nine of the samples were mildly suppressive to P. ultimum, the others were conducive. The bark compost sample was strongly suppressive. Therefore of the examined composts, only the bark could be used to exert an economically relevant control of P. ultimum in horticultural media. A large part of the compost samples was slightly phytotoxic. Microbial biomass and SIR had only weak correlations with disease incidence. Microbial activity and content of extractible phenolics were positively correlated with disease incidence. None of the tested parameters were therefore suitable as a predictive test for suppression of P. ultimum with the compost samples used in this study.  相似文献   

18.
BERGQUIST  R. R. 《Annals of botany》1974,38(1):213-221
Three fungicide rates, 4·48, 2.24, and 1.12 kg peT ha,and four spray intervals, 5, 7, 10, and14-day intervals, were investigated for the control of Phytophthoraleaf blight of taro in a subtropical field environment in Hawaii.The fungicide rate was studied in two separate locations onthe windward sides of the island of Kauai. The fungicide utilizedin these experiments was a co-ordination product of zinc ionand manganese ethylene bisdithiocarbamate (Dithane M-45, 80per cent WP). In the lower rainfall location, there was no differencedue to different fungicide rates while in the wetter location,the 4·48 kg per ha rate gave better control than the1·12 kg per ha rate. There was no significant differencebetween the 5, 7, and IO-day spray intervals butwhen compared with the 14-day interval, the 5-day interval wassuperior. Periods of increased rainfall were reflected in thefollowing week by increased lesion counts. Present data indicatethat rainfall is a major factor to consider as a basis for predictingdisease was occurrences and may be utilized for planning intervalof fungicide application. The amount of disease was a functionof initial disease levels, rainfall, temperature, relative humidity,fungicide rate, and spray interval between fungicide applications.Applications of fungicide at weekly intervals when weekly rainfallaccumulation exceeded 1 cm per week and/or when lesion countsexceeded more than one per plant gave substantial disease control.Thus, once these parameters of disease have been established,fungicide application could be governed conveniently by monitoringrainfall and disease incidence to achieve practical Phytophthowraleaf blight control. The 2·24 and 4·48 kg ha-1rates gave significant yield increases over the 1·12and check (no fungicide) treatments where Phytophthora leafblight occurred in epidemic proportions.  相似文献   

19.
S ummary : Strains of Aspergillus flavus recently isolated from coconut products were cultured on grated coconut. The aflatoxin content of serial cultures was found to vary significantly with duration of incubation and for some strains to show more than one phase of increase of aflatoxin content. The occurrence of these variations indicates that the study of aflatoxigenic capacity of strains or of the capacity of a medium to support toxin production, should be based upon a knowledge of the pattern of variation of toxin content with duration of incubation of the cultures under the experimental conditions used. Assay of toxin level in a culture after one period of incubation could lead to erroneous conclusions about the identity or quantities of toxin components which the strain is able to produce.  相似文献   

20.
目的:探讨生大黄保留灌肠对重症急性胰腺炎(SAP)患者胃肠激素和炎症反应的影响。方法:选取2012年1月~2017年1月间我院收治的SAP患者110例,采用随机数字表法将患者分为对照组(n=55)和研究组(n=55),对照组给予常规西医治疗,研究组在对照组基础上给予生大黄保留灌肠治疗,比较两组临床疗效、临床指标改善情况、炎症因子、血淀粉酶以及胃肠激素水平。结果:研究组治疗后的临床总有效率为74.55%(41/55),高于对照组患者的54.55%(30/55)(P0.05)。研究组肠道功能恢复时间、全身炎症反应综合征(SIRS)消退时间、住院天数均短于对照组,研究组并发症发生率低于对照组(P0.05)。两组患者治疗后白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、超敏C反应蛋白(hs-CRP)、血淀粉酶水平均降低,且研究组低于对照组(P0.05)。两组患者治疗后胃动素(MTL)、胆囊收缩素(CCK)水平升高,血管活性肠肽(VIP)水平降低(P0.05),研究组治疗后MTL、CCK水平高于对照组,VIP水平低于对照组(P0.05)。结论:生大黄保留灌肠治疗SAP患者疗效确切,可减轻炎症反应,改善患者血淀粉酶水平及胃肠道功能,促进患者恢复。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号