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1.
The aim of this work was to assess the effect of applying three different doses of fluxapyroxad on microbial activity, community structure and functional diversity as measured by respiration, microbial biomass C, phospholipid fatty acid(PLFA) and community-level physiological profiles(CLPPs). Our results demonstrated that substrate-induced respiration(on day 15) and microbial biomass C(on days 7 and 15) were inhibited by fluxapyroxad, but stimulation was observed thereafter. In contrast, fluxapyroxad addition increased the basal respiration and metabolic quotients(q CO2) and respiratory quotients(QR). Analysis of the PLFA profiles revealed that the total and bacterial biomass(both Gram-positive bacteria(GP) and Gram-negative bacteria(GN)) were decreased within the initial 15 days, whereas those as well as the GN/GP ratio were increased at days 30 and 60. F luxapyroxad input decreased the fungi biomass but increased the bacteria/fungi ratio at all incubation time. Moreover, high fluxapyroxad input(75 mg fluxapyroxad kg–1 soil dry weight) increased the microbial stress level. A principal component analysis(PCA) of the PLFAs revealed that fluxapyroxad treatment s ignificantly shifted the microbial community structure, but all of the observed effects were transient. Biolog results showed that average well color development(AWCD) and functional diversity index(H′) were increased only on day 60. I n addition, the dissipation of fluxapyroxad was slow in soil, and the degradation half-lives varied from 158 to 385 days depending on the concentration tested.  相似文献   
2.
Anagrus nilaparvatae is the dominant egg parasitoid of rice planthoppers and plays an important role in biological control. Symbiotic bacteria can significantly influence the development, survival, reproduction and population differentiation of their hosts. To study the influence of temperature on symbiotic bacterial composition in the successive generations of A. nilaparvatae, A. nilaparvatae were raised under different constant temperatures of 22 °C, 25 °C, 28 °C, 31 °C and 34 °C. Polymerase chain reaction-denaturing gradient gel electrophoresis was used to investigate the diversity of symbiotic bacteria. Our results revealed that the endophytic bacteria of A. nilaparvatae were Pantoea sp., Pseudomonas sp. and some uncultured bacteria. The bacterial community composition in A. nilaparvatae significantly varied among different temperatures and generations, which might be partially caused by temperature, feeding behavior and the physical changes of hosts. However, the analysis of wsp gene showed that the Wolbachia in A. nilaparvatae belonged to group A, sub-group Mors and sub-group Dro. Sub-group Mors was absolutely dominant, and this Wolbachia composition remained stable in different temperatures and generations, except for the 3rd generation under 34 °C during which sub-group Dro became the dominant Wolbachia. The above results suggest that the continuous high temperature of 34 °C can influence the Wolbachia community composition in A. nilaparvatae.  相似文献   
3.
Remote sensing as the measure to monitor disasters has the advantage of temporal resolution and large scale. Since "5.6 catastrophe" in 1987, China began to monitor forest fires broadly. In the summer of 2002, many forest/grass fires occurred in the Daxing'anling Mountains, and the damage was very heavy. In the forest fires fighting, the meteorological satellites play an important role in monitoring the fires. Especially the FY serial meteorological satellites have the advantage of large scale monitoring and characteristics of being in time and exact, and get good results. Remote sensing techniques have been used in many aspects of forest/grass fires research, including burned area and fireline intensity evaluation, post fire environment monitoring etc.  相似文献   
4.
Basedon the results of monitoring the environment of China National Afforestation Project (NAP) and the investigation on insect pests and diseases in 1.2 million ha of plantations, the author elaborates the areas, species and causes of insect pests and diseases occurring in the project's areas and provides fundamental theory for guiding environmental protection and plantation establishment in a sound way. Since the project's activities strictly follovved the guideline of environmental protection in past five years, little losses were caused by some commonly insect pests and diseases.  相似文献   
5.
根据国家森林防火指挥部领导的指示要求,国家林业局防火办组成了由国家森防指专家组成员、森林防火专业委员会主任朴东赫带队的秋防工作检查组,于2007年10月12日~19日赶赴黑龙江省,对当地秋季森林防火工作进行了检查调研。检查期间,工作组主要采取实地检查、抽查、座谈了解、听取汇报等方式,重点检查了哈尔滨、佳木斯、鹤岗三个地市辖区内的地方林业局、省森工总局林管局、  相似文献   
6.
澳大利亚、新西兰天然林保护管理对我国的启示   总被引:2,自引:0,他引:2  
文章介绍了澳大利亚和新西兰两国的天然林经营保护方面的基本情况和做法,提出进一步完善我国正在实施的天然林保护工程政策和管理机制,如制定符合国际林业发展趋势和我国国情的天然林资源保护政策;大力发展人工林,提高林产品产量进而促进天然林保护;加强国际合作,提高我国天然林可持续经营能力等。  相似文献   
7.
石家庄污灌区污水灌溉技术的研究   总被引:14,自引:1,他引:14  
分析了国内外污水灌溉的研究和发展,以石家庄市污灌区为研究对象,在分析预测未来30年污水水质水量特点的基础上,采用不同的灌水技术,利用环境容量法,分析预测了在不同务件下土壤和作物中重金属和石油类浓度的发展以及相应的污清水的灌溉需水量。针对该灌区土壤现状和污水水质特点,提出了建议的合理污水灌溉技术,以保证以土壤为中心的生态系统的可持续发展。  相似文献   
8.
马鞍山市向山垃圾填埋场抽气实验研究   总被引:4,自引:0,他引:4  
本文根据马鞍山市向山垃圾填埋场的现场抽气实验,分析了影响垃圾填埋气体产生的各因素的变化规律,确定了抽气压力、气体流量和甲烷含量的关系及其影响因素,并以此为基础对填埋气体收集利用工程中填埋场的选择和系统的设计提出了建议。  相似文献   
9.
大豆抗原蛋白的组成及其致敏作用机理   总被引:1,自引:0,他引:1  
本文综述了大豆抗原蛋白的分类、组成和特征,以及大豆球蛋白与β -伴大豆球蛋白可能的致敏作用机理.  相似文献   
10.
Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most widespread and destructive wheat diseases in many wheat-growing regions of the world. The winter wheat translocation line H9014-14-4-6-1 has all stage resistance. To identify stripe rust resistance genes, the segregating populations were developed from the cross between H9014-14-4-6-1 and Mingxian 169 (a wheat cultivar susceptible to all Pst races identified in China). The seedlings of the parents and F 1 plants, F2 , F3 and BC 1 generations were tested with Pst races under controlled greenhouse conditions. Two genes for resistance to stripe rust were identified, one dominant gene conferred resistance to SUN11-4, temporarily designated YrH9014 and the other recessive gene conferred resistance to CYR33. The bulked segregant analysis and simple sequence repeat (SSR) markers were used to identify polymorphic markers associated with YrH9014. Seven polymorphic SSR markers were used to genotype the F2 population inoculated with SUN11-4. A linkage map was constructed according to the genotypes of seven SSR markers and resistance gene. The molecular map spanned 24.3 cM, and the genetic distance of the two closest markers Xbarc13 and Xbarc55 to gene locus was 1.4 and 3.6 cM, respectively. Based on the position of SSR marker, the resistance gene YrH9014 was located on chromosome arm 2BS. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xbarc13 indicated that YrH9014 was located on chromosome 2B. Based on chromosomal location, the reaction patterns and pedigree analysis, YrH9014 should be a novel resistance gene to stripe rust. This new gene and flanking markers got from this study should be useful for marker-assisted selection (MAS) in breeding programs for stripe rust.  相似文献   
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