Pathogenicity and Virulence of the Two Dutch VCGs of Verticillium dahliae to Woody Ornamentals

Two experiments were performed in two consecutive years to test whether isolates of different vegetative compatibility groups (VCGs) differ in their ability to cause disease in woody ornamentals, to study the host specificity of the isolates and to get an insight into disease development in woody hosts. A range of woody ornamental plant species, including Acer campestre, Acer platanoides, Acer pseudoplatanus, Catalpa bignonioides, Cotinus coggygria, Robinia pseudoacacia, Rosa canina, Syringa vulgaris and Tilia cordata, were root-dip inoculated with six isolates of Verticillium dahliae, belonging to the two VCGs that occur in the Netherlands (VCG NL-1 and VCG NL-2). Isolates belonging to each VCG caused severe symptoms of verticillium wilt in most plant species tested. Disease progress differed between plant species, but was generally the same for the two VCGs. No overall differences in virulence were observed between the two VCGs for external wilt symptoms, number of dead plants, or shoot length. No significant VCG × plant species interactions were present for these characteristics. However, isolates of VCG NL-1 caused more vascular discolouration than did isolates of VCG NL-2. Isolates within VCGs often differed considerably in their virulence to certain hosts, as shown by highly significant isolate × plant species interactions. Isolates were more virulent on their original host. These findings imply that VCG identification does not contribute to disease prediction for a range of woody hosts.     

扫描昆虫雷达实时数据采集、分析系统

利用自行设计、制作的扫描昆虫雷达数据采集分析系统,对扫描雷达回波的VGA图像信号进行单帧采集和多幅序列采集,经过图像处理、参数自动识别和回波的自动分析、计算后可得到昆虫活动的方位、高度、距离、密度、飞行的方向和速度等一系列迁飞活动数据。对迁飞昆虫活动实时监测,实现该类害虫的准确预测和有效治理具有非常重要的作用。     

我国热带牧草种质资源的收集、保存与利用现状

介绍了牧草种质资源的作用及我国热带牧草种质资源的收集、保存与利用的现状,提出了加强我国热带牧草种质资源工作的几点建议.     

The impact of truncating data on the predictive ability for single‐step genomic best linear unbiased prediction

Simulated and swine industry data sets were utilized to assess the impact of removing older data on the predictive ability of selection candidate estimated breeding values (EBV) when using single‐step genomic best linear unbiased prediction (ssGBLUP). Simulated data included thirty replicates designed to mimic the structure of swine data sets. For the simulated data, varying amounts of data were truncated based on the number of ancestral generations back from the selection candidates. The swine data sets consisted of phenotypic and genotypic records for three traits across two breeds on animals born from 2003 to 2017. Phenotypes and genotypes were iteratively removed 1 year at a time based on the year an animal was born. For the swine data sets, correlations between corrected phenotypes (Cp) and EBV were used to evaluate the predictive ability on young animals born in 2016–2017. In the simulated data set, keeping data two generations back or greater resulted in no statistical difference (p‐value > 0.05) in the reduction in the true breeding value at generation 15 compared to utilizing all available data. Across swine data sets, removing phenotypes from animals born prior to 2011 resulted in a negligible or a slight numerical increase in the correlation between Cp and EBV. Truncating data is a method to alleviate computational issues without negatively impacting the predictive ability of selection candidate EBV.     

我国木门自动化制造特点及发展趋势

木门加工装备的自动化水平直接影响木门的生产效率和产品质量,并决定企业的竞争力.笔者依据国内木门自动化制造领域丰富的实践经验,对我国木门自动化制造的特点及未来发展趋势进行了分析,为木门生产企业加工装备升级提出建议.     

自动折叠喷洒臂的设计及运动学特性

为了解决当前卷盘式喷灌机所配套的喷灌车自动化水平较低的问题,设计了一种基于电动缸驱动的自动折叠喷洒臂,并在喷洒臂之间连接处设计了一种当喷洒臂完全展开时能够实现自密封的端面密封铰链.基于喷洒臂完全折叠时收拢于车架两侧,完全伸展时铰链左右铰合密封等特征建立各杆件参数约束方程,确定了喷洒臂的各杆件尺寸.通过矢量方程法对喷洒臂进行运动学分析,以电动杆推杆的转角、位移、速度、加速度为输入量,各杆件的角位移、角速度、角加速度为输出量,通过Simulink搭建喷洒臂的运动仿真框图并进行分析.结果表明:完全折叠时,喷管1与水平方向呈90°夹角;伸展过程中,各喷管运动平稳,且始终保持在水平直线方向;完全展开时,3个喷管转动90°,且各喷管铰接处完全闭合不发生水泄漏现象,说明设计具有一定的合理性.     

广西县级林地变更调查试点技术方法

为探索广西县级林地年度变更调查技术方法,以鹿寨县为例,运用遥感自动检测技术、森林资源管理信息平台等,对地类及管理属性变化图斑进行变更,形成本期林地数据库和林地变化数据库。文章分析了林地变更调查的关键技术方法,指出了存在的问题,并提出相应的建议。     

自动润滑装置在数控无卡轴旋切机上的应用

数控无卡轴旋切机的刀台进给系统通过丝杠螺母的传动可实现刀体座的进退,传动丝杠螺母都是依靠人工润滑,如果润滑不及时就会出现粘牙现象而导致整个设备不能工作。介绍了一种自动润滑装置,其可实现对丝杠螺母的自动润滑。     

关于地理空间数据整合与持续高效更新存在的问题分析

文章针对当前地理空间数据整合与持续高效更新所存在的问题,在地理空间数据更新中引入了“数据同化”这一思想和概念,对持续高效更新存在的问题及“地理空间数据同化”的涵义和关键技术进行了论述.     

新疆林业海量影像数据管理系统建设

介绍新疆林业海量影像数据管理系统建设的关键技术和系统功能。系统通过对多源、多时相、多分辨率的影像数据的统一化、标准化的组织和管理,提供在线影像浏览、查询、对比分析和影像下载等功能,实现了海量影像数据的管理与共享。