Forest Mapping with ERS SAR Tandem Data     

Mike WOODING  Franck RANERA  Betlem ROSICH 《中国林业科技(英文版)》2002,(2)

The feasibility of ERS SAR Tandem data for mapping forest and non-forest cover in China was evaluated over Zengcheng County in the South China. An accuracy of 75% has been achieved. Then, the MACFERST (Mapping China Forest with ERS SAR Tandem data) project started by the Ministry of Science and Technology (MOST) of China and the European Space Agency (ESA) in 1999. The generation of a large-scale forest map requires solving problems such as the georeferencing and mosaicking of very long image strips covering huge regions and the adaptation of the classification algorithm to account for radiometric differences. Approaches to solve these problems and the classification results in the Northeastern of China will be presented in this paper.  相似文献   

HRAP基因诱导型植物表达载体的构建及烟草转化   总被引：1，自引：0，他引：1  

王爱英  缪建锟  彭晓明  沈海涛  祝建波 《西北农业学报》2009,18(6):157-160

系统获得性抗性是植物抵御病菌侵染的一种独特的防御机制.HRAP基因是一种从甜胡椒中克隆的蛋白质激发子,可以有效引发植物系统性抗性.SAR8.2b基因是烟草系统获得性抗性信号传导途径中下游响应基因,受病原物和水杨酸诱导.本试验根据Genebank发布SAR8.2b基因的启动子序列,利用PCR技术,克隆了SAR8.2b基因的完整启动子,命名为SAR8.2bP,然后将SAR8.2bP构建到pUC18-HRAP载体中命名为pUC18-SAR8.2bP-HRAP,然后用SAR8.2bP-HRAP替换p2300-121载体中的35S启动子和GUS基因,重组子命名p2300-SAR8.2bP-HRAP.将构建的植物表达载体转化农杆菌GV3101,利用叶盘法转化烟草,通过PCR筛选,获得了转基因植株.为进一步验证转基因烟草的抗病效果奠定了基础.  相似文献   

Aromatic‐ring‐functionalised benzoxazinones in the system Oryza sativa–Echinochloa crus‐galli as biorational herbicide models     

Francisco A Macías  Nuria Chinchilla  Rosa M Varela  José MG Molinillo  David Marín  Joao M de Siqueira 《Pest management science》2009,65(10):1104-1113

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Fire models and methods to map fuel types: The role of remote sensing   总被引：1，自引：0，他引：1  

Lara A. Arroyo  Cristina PascualJosé A. Manzanera 《Forest Ecology and Management》2008

Understanding fire is essential to improving forest management strategies. More specifically, an accurate knowledge of the spatial distribution of fuels is critical when analyzing, modelling and predicting fire behaviour. First, we review the main concepts and terminology associated with forest fuels and a number of fuel type classifications. Second, we summarize the main techniques employed to map fuel types starting with the most traditional approaches, such as field work, aerial photo interpretation or ecological modelling. We pay special attention to more contemporary techniques, which involve the use of remote sensing systems. In general, remote sensing systems are low-priced, can be regularly updated and are less time-consuming than traditional methods, but they are still facing important limitations. Recent work has shown that the integration of different sources of information and methods in a complementary way helps to overcome most of these limitations. Further research is encouraged to develop novel and enhanced remote sensing techniques.  相似文献   

壳寡糖诱导对烟草体内TMV-CP基因表达的抑制作用   总被引：1，自引：0，他引：1  

商文静  吴云锋  商鸿生  赵小明  杜昱光 《植物病理学报》2007,37(6):637-641

 采用实时荧光定量PCR方法, 研究了壳寡糖诱导对烟草体内TMV-CP基因表达量的影响。结果表明, 壳寡糖诱导后烟草表达了对TMV侵染的系统获得抗病性, 植株显症推迟4~7 d, 症状减轻, 平均严重度比对照降低了82.9%。同时烟草叶片中CP基因的表达量显著降低。壳寡糖诱导处理的植株在接种病毒时(0 h), CP基因的表达量(拷贝数/2μL)为0.918, 接种后168 h增加到167.730。而在不诱导对照植株内, CP基因的表达量在0 h为1.218, 接种后168 h猛增到648.623。换言之, 不处理对照的表达量在此期间增长了532.53倍, 而壳寡糖诱导处理植株中仅增长了182.71倍。试验证明壳寡糖诱导的系统获得抗病性强烈抑制了烟草体内TMV-CP基因的表达。  相似文献   

干旱区施不同浓度硝酸钾对后备耕地土壤水盐的影响   总被引：1，自引：1，他引：1  

王莉峰  熊黑钢  靳彦华  鲁魁锋 《水土保持学报》2013,27(4)

采用野外试验和室内分析相结合的方法,研究施用不同量硝酸钾对新疆盐碱土水盐及离子分布的影响.结果表明:(1)随着外源硝酸钾施入土壤,土壤上层含水率增加,下层减少.(2)土壤上层的全盐含量增大,并且施钾浓度越高含盐量也越高.(3)施钾样地整个土层的Ca2+、Mg2+、SO42-浓度相对于对照地(非施钾样地)有所增加,而Na+和Cl-浓度降低.当施钾浓度为400mg/L时上层Na+浓度显著增加,可能对作物造成危害;施钾浓度达到1 000mg/L时Na+浓度变化不大,即施钾浓度越高Na+浓度越低.(4)施钾浓度为1 000 mg/L时,土壤上层钠吸附比(SAR)、Cl-/SO42-大大降低.施用硝酸钾可增加后备耕地土壤上层的含水量,减少钠吸附比(SAR)、Cl-/SO42-,有利于农作物的生长,但也增加了土壤上层的含盐量.  相似文献   

三种材料复合施用对盐碱土壤改良效果的研究   总被引：1，自引：0，他引：1  

金梦野  李小华  黄占斌  杨永安 《农业环境科学学报》2020,37(5):719-726

为研发对盐碱土壤脱盐和对土壤结构具有同步改良效应的复合改良材料,选取脱硫石膏（A）、改性腐植酸（B）和高分子材料（C）,通过室内土柱模拟方法,采用正交试验设计,探究三种材料对盐碱土壤盐分淋洗和结构改良同步增效的最优组合,分析不同材料对盐碱土壤的改良机理。结果表明：三种材料复合施用对盐碱土壤盐分淋洗和结构改良有明显效果,对盐碱土壤改良效果最优的组合为A₃B₁C₃（脱硫石膏、改性腐植酸、高分子材料的添加量分别为60、2、0.1 g·kg^-1）,与对照（CK）相比,其淋溶液体积减少了14.22%,土壤钠吸附比（SAR）降低了30.43%,土壤团聚体含量增加24.45个百分点。研究表明,三种材料复合施用能够在改良盐碱土壤化学性质的同时改良盐碱土壤结构。  相似文献   

Synthesis and testing of novel alternative oxidase (AOX) inhibitors with antifungal activity against Moniliophthora perniciosa (Stahel), the causal agent of witches' broom disease of cocoa,and other phytopathogens     

Mario RO Barsottini  Brbara A Pires  Maria L Vieira  Jos GC Pereira  Paulo CS Costa  Jaqueline Sanit  Alessandro Coradini  Fellipe Mello  Cidnei Marschalk  Eder M Silva  Daniele Paschoal  Antonio Figueira  Fbio HS Rodrigues  Artur T Cordeiro  Paulo CML Miranda  Paulo SL Oliveira  Maurício L Sfora  Marcelo F Carazzolle  Silvana A Rocco  Gonalo AG Pereira 《Pest management science》2019,75(5):1295-1303

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Novel 4‐pyrazole carboxamide derivatives containing flexible chain motif: design,synthesis and antifungal activity     

Xing‐Hai Liu  Li Qiao  Zhi‐Wen Zhai  Peng‐Peng Cai  Charles L Cantrell  Chen‐Xia Tan  Jian‐Quan Weng  Liang Han  Hong‐Ke Wu 《Pest management science》2019,75(11):2892-2900

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钠吸附比和盐分浓度对新疆典型砂壤土物理性质的影响     

许尊秋  陈阳  毛晓敏 《农业工程学报》2022,38(20):86-95

新疆土壤盐碱化问题严重影响农田水盐运移和作物产量。为探究钠吸附比（Sodium Adsorption Ratio,SAR）和盐分浓度对当地典型砂壤土物理性质的影响,该研究测定了4个SAR水平（40,30,20,15,10,5(mmol/L)1/2）和8个盐分浓度水平（200,150,100,50,20,10,5,2mmol/L）下土壤团聚体快速湿润过程中的团聚体水稳性;并测定了4个SAR水平（40,30,20,5 (mmol/L)1/2）和3个盐分浓度水平（200,100,20 mmol/L）溶液处理后的土壤水分特征曲线（Soil Water Characteristic Curve,SWCC）,量化了土壤脱水过程中土体压缩量与溶液SAR和盐分浓度的关系。结果表明：1）土壤团聚体水稳性与SAR和盐分浓度均呈显著负相关关系,SAR高于30 (mmol/L)1/2时,土壤团聚体水稳性才会显著下降;2)SAR对新疆典型砂壤土的SWCC有影响,且这种影响与盐分浓度有关;3）盐分浓度和SAR对土壤压缩量的影响存在交互作用。研究结果可为合理选用不同盐分组成和浓度微咸水灌溉以最大程度保护农田土壤结构...  相似文献