Experimental infections with Lepeophtheirus salmonis (Krøyer) on threespine sticklebacks, Gasterosteus aculeatus L., and juvenile Pacific salmon, Oncorhynchus spp

Experimental infections with Lepeophtheirus salmonis (Krøyer) were established on threespine sticklebacks, Gasterosteus aculeatus L., juvenile pink, Oncorhynchus gorbuscha (Walbaum), and chum, Oncorhynchus keta (Walbaum), salmon. The prevalence and abundance of infections were initially higher on sticklebacks than on either salmon species. The initial prevalence and intensity of infections on chum salmon were higher than those on pink salmon, and declined on both species during louse development. The rate of parasite development to adult stages was similar on all species although development beyond the preadult stage was not observed on sticklebacks. These results confirm previous field observations on the occurrence and development of L. salmonis on threespine sticklebacks.     

化学实验室中的污染问题与防治对策

化学实验室排放的大量废液、废气及固体废弃物已经造成严重的环境污染.缺乏实验室环保意识和实验室污染控制的经费投入是其产生的主要原因.加强化学实验室管理及环境教育,进行实验室废物的回收再利用,分类收集与区别处理是解决问题的主要途径.     

对省级重点实验室管理的几点建议——以河北省农林科学院为例

以河北省农林科学院为例,阐述了省级重点实验室的建设情况及其在科技工作中发挥的重要作用,并提出了加强省级重点实验室管理的建议。     

豇豆轮纹病病原鉴定及其室内药剂筛选

从海南三亚豇豆设施棚内采集具典型轮纹病病斑的豇豆叶片,采用组织分离法分离到1株致病菌,根据病害症状特点、病原菌形态特征、培养性状、ITS序列分析,鉴定豇豆轮纹病的病原菌为多主棒孢霉[Corynespora cassiicola (Berk. & Curst.) Wei];利用生长速率法,对12种药剂进行室内筛选,结果表明：10%苯醚甲环唑(WP,可湿性粉剂)和50%异菌脲(WP)对病原菌具有强烈抑制作用,其EC50分别为2.709 46和9.093 27 mg/L,而75%百菌清(WP)和50%多菌灵(W     

基于SuperMap的松嫩平原科研成果管理系统的设计与实现

当前如何规范科研成果管理工作,是实验室全面提高成果管理水平所面临的重点问题之一。为了实现信息化和标准化的松嫩平原科研成果管理,在对实验室科研成果管理需求进行详细分析的基础上,进行了系统结构设计和实现。基于SuperMap Objects .NET 6R和SQL Server开发了松嫩平原科研成果管理系统。结果表明,该系统对成果文件或空间和属性信息进行管理和统计是非常高效的,对科研成果管理具有特别重要意义。     

关于我国新一轮农业部重点实验室建设的思考

农业领域重点实验室是国家农业科技创新体系的重要组成部分。文章分析了我国农业领域重点实验室建设现状,阐述了新一轮农业部重点实验室建设的必要性,并就加强农业部重点实验室的运行与管理提出了应加强统筹管理,提高运行效率;加强经费支持,稳定研究方向;加强考核评估,适当动态调整;加强科研合作,实现资源共享等建议。     

Improving in-season nitrogen recommendations for maize using an active sensor

An active crop canopy reflectance sensor could be used to increase N-use efficiency in maize (Zea mays L.), if temporal and spatial variability in soil N availability and plant demand are adequately accounted for with an in-season N application. Our objective was to evaluate the success of using an active canopy sensor for developing maize N recommendations. This study was conducted in 21 farmers’ fields from 2007 to 2009, representing the maize production regions of east central and southeastern Pennsylvania, USA. Four blocks at each site included seven sidedress N rates (0–280 kg N ha⁻¹) and one at-planting N rate of 280 kg N ha⁻¹. Canopy reflectance in the 590 nm and 880 nm wavelengths, soil samples, chlorophyll meter (SPAD) measurements and above-ground biomass were collected at the 6th–7th-leaf growth stage (V6–V7). Relative amber normalized difference vegetative index (ANDVI_relative) and relative SPAD (SPAD_relative) were determined based on the relative measurements from the zero sidedress treatment to the 280 kg N ha⁻¹ at-planting treatment. Observations from the current study were compared to relationships between economic optimum N rate (EONR) and ANDVI_relative, presidedress NO₃ test (PSNT), or SPAD_relative that were developed from a previous study. These comparisons were based on an absolute mean difference (AMD) between observed EONR and the previously determined predicted relationships. The AMD for the relationship between EONR and ANDVI_relative in the current study was 46 kg N ha⁻¹. Neither the PSNT (AMD = 66 kg N ha⁻¹) nor the SPAD_relative (AMD = 72 kg N ha⁻¹) provided as good an indicator of EONR. When using all the observations from the two studies for the relationships between EONR and the various measurements, ANDVI_relative (R² = 0.65) provided a better estimate of EONR than PSNT (R² = 0.49) or SPAD_relative (not significant). Crop reflectance captured similar information as the PSNT and SPAD_relative, as reflected in strong relationships (R² > 0.60) among these variables. Crop canopy reflectance using an active sensor (i.e. ANDVI_relative) provided as good or better an indicator of EONR than PSNT or SPAD_relative, and provides an opportunity to easily adjust in-season N applications spatially.     

Soil Testing Bray-1 Phosphorus with Non-Reagent Grade Hydrochloric and Sulfuric Acids

Portable instruments have reduced on-site testing costs for soil pH and potassium in isolated locations. Acids could not be shipped to a remote Africa field laboratory. Bray-1 phosphorus (P) testing is difficult because hydrochloric (HCl) is required in the extraction solution and sulfuric acid (H₂SO₄) is used in color development stock solutions. Muriatic HCl acid and battery H₂SO₄ were available in a local stores. The objectives of this study were to evaluate the accuracy of P soil testing using diluted, non-reagent HCl for making modified Bray1-P extractant and non-reagent H₂SO₄ for color development. Experiment 1 was conducted with soil samples from fields using Sunnyside? and Klean Strip? HCl muriatic acids. Soil samples extracted with diluted reagent HCl were closely related to P results using diluted Klean Strip (R² = 0.96) and Sunnyside (R² = 0.84) HCl. In Experiment 2, two commercial brands of H₂SO₄ acid used to refill car battery cells were evaluated. Test results suggested that the battery H₂SO₄ acids are not suitable for making color development solution. In Experiment 3, a small battery powered spectrometer for P testing aquarium water was calibrated for soils. Samples from the Soil Science Society of America –North American Proficiency Testing program (NAPT) were tested with the meter and non-reagent HCl. Fiske-Subbarrow reducing agent and HCl were used in a variation procedure which does not require H₂SO₄ for color development. Eight of 10 samples tested proficient based on NAPT limits (2.5 x Median Absolute Deviation).     

不同温度下东方粘虫年龄-阶段两性实验种群生命表的构建

为明确不同温度对东方粘虫Mythimna separata(Walker)种群动态的影响,建立东方粘虫种群动态模型,利用年龄-阶段两性种群生命表得到了室内不同温度下东方粘虫种群的发育历期、存活率、繁殖力和种群生命表参数,并基于种群生命表参数预测了2个月内东方粘虫的种群动态。结果表明,东方粘虫各虫态的发育历期和产卵前期随温度的升高而显著缩短。24℃下,东方粘虫单雌平均产卵量为717.1粒,显著高于其它温度下;成虫寿命也显著高于其它温度下,且雄蛾寿命显著长于雌蛾,分别为15.3 d和13.0 d;卵孵化存活到成虫的概率、幼虫存活率和化蛹率均最高,分别为66.7%、68.9%和96.8%。内禀增长率随温度的升高而显著增加,平均世代周期则显著降低,18、21、24、27、30℃下分别为0.051、0.077、0.113、0.121、0.156 d-1和77.2、61.3、49.0、40.3、31.5 d;周限增长率也随温度的升高而增加,分别为1.05、1.08、1.12、1.13、1.17 d-1;净增殖率在24℃下为257.1,显著高于其它温度下,其它温度条件下无显著差异。表明东方粘虫在18~30℃范围内都能完成生长发育和生殖,24℃下种群存活率高、繁殖力大、世代周期较短,更适合种群增长。