水稻潜根线虫生防菌筛选、鉴定及其杀线虫活性研究

水稻潜根线虫在世界各稻区均普遍发生,给水稻生产造成一定的经济损失。从前期对根结线虫有较好毒杀活性的9个菌株中筛选出对水稻潜根线虫有很好毒杀效果的菌株。结果表明,2周发酵液2.5倍稀释液处理水稻潜根线虫,菌株ZW-1和XO-2对潜根线虫毒杀活性较强,72h的死亡率分别为93.7%和96.7%,LC₅₀值分别为90.4451和76.3875μL/mL。根据形态学特征和rDNA-ITS序列分析,鉴定菌株ZW-1和XO-2分别为日本曲霉(Aspergillus japonicus)和黑曲霉(A.niger)。这些生防真菌菌株的发掘,为植物线虫病害的生物防治提供了新的微生物资源。     

基于深度学习服务的遥感影像农作物分类系统设计

【目的】深度学习在图像分类方面效果显著,但对机器的硬件配置要求高,将深度学习的技术应用于作物分类的同时,降低客户端的IT成本,开发基于深度学习服务的遥感影像农作物分类系统。【方法】系统采用C/S架构,服务器端部署Caffe的深度学习框架,通过PaaS提供计算服务,统一处理客户端模型训练、影像分类等任务;客户端提供用户界面,负责数据输入、结果解析和可视化操作;客户端和服务器之间通过异步RPC实现网络通信,利用FTP进行数据的上传和下载;考虑到农作物分类在实际应用中的时效性,系统还提供了一个简化的Alexnet模型,在保证分类精度的前提下加速了模型的收敛速度。【结果】通过对采集的428144个农作物样本数据集的应用表明,服务器训练的时间比单机训练缩短了近3倍,该系统不仅能够快速地完成深度学习模型训练的任务,还能实时准确得到遥感影像的农作物分类结果。【结论】该研究进一步推动了深度学习在农业分类方面的应用,同时为遥感技术在农业应用中的发展、农作物面积统计工作和对农业资源进行优化配置提供了重要的科学指导。     

Early growth analysis and evaluation of 21 Eucalyptus clones in Leizhou Peninsula

The growth, morphology, and wind resistance of 21 Eucalyptus clones were investigated and analyzed in Leizhou Peninsula, Zhanjiang city. The results showed that coefficient of variation of each index phenotype varied from 15.21%-42.46%. There were significant differences among the clones in growth indexes. The top five clones with high individual volume were JJ144, 2#, 28#, 9#, and JJ197. The morphological indexes were significantly different among the clones. There were also significant differences among the clones in wind resistance index, and the clones with good wind resistance were 28#, JJ162, JJ195 and JJ215, their preservation rate were more than 80%. It was found that tree height and DBH significantly correlated to individual volume, and stem form was significantly related to branch. Using the principal component analysis, it was determined that JJ144, 2#, 28#, 9# and JJ162 were the excellent clones with good performance in the Leizhou area.     

一起经营、加工病死动物案的查处

本文对一起经营、加工病死动物案的案件来源、调查经过及结果、案件移交、处理结果进行了梳理,认定本案性质较为严重,总体上违法事实清楚,证据确凿,定性准确,处理适当,程序合法。本文从执法主体认定,物证流失,动物卫生监督机构责任规避等作了分析和讨论,认为执法人员应加强法律法规学习,提高监督执法水平,以期为官方兽医办理此类案件提供借鉴。     

辽宁地区玉米品种植株农艺性状演化研究

通过对1998年至2014年参加辽宁省玉米品种区域试验的2347个品种植株农艺性状演化的分析,掌握了近些年玉米品种农艺性状的变化规律和不同类型间的关键区别。积温需求方面,极晚熟晚熟类中晚熟类中熟;成株株高和穗位高方面,也表现出相同的趋势;除极晚熟品种,其他类型品种成株叶片数都呈下降趋势;除极晚熟品种和中熟品种外,其他类型品种倒伏倒折率之和呈下降趋势。中熟品种熟期和植株农艺性状均较理想,是中晚熟品种的发展方向。中晚熟类品种和晚熟类品种在形态上有趋同性,在以后的选育过程中应予以区分。极晚熟品种有个体大型化发展的趋势,直接导致抗倒性下降。     

Morphological diversity of Paramoeba perurans trophozoites and their interaction with Atlantic salmon,Salmo salar L., gills

Amoebic gill disease (AGD) caused by the ectoparasite Paramoeba perurans affects several cultured marine fish species worldwide. In this study, the morphology and ultrastructure of P. perurans in vitro and in vivo was investigated using scanning and transmission electron microscopy (SEM and TEM, respectively). Amoebae cultures contained several different morphologies ranging from a distinct rounded cell structure and polymorphic cells with pseudopodia of different lengths and shapes. SEM studies of the gills of AGD‐affected Atlantic salmon, Salmo salar L., revealed the presence of enlarged swellings in affected gill filaments and fusion of adjacent lamellae. Spherical amoebae appeared to embed within the epithelium, and subsequently leave hemispherical indentations with visible fenestrations in the basolateral surface following their departure. These fenestrated structures corresponded to the presence of pseudopodia which could be seen by TEM to penetrate into the epithelium. The membrane–membrane interface contained an amorphous and slightly fibrous matrix. This suggests the existence of cellular glycocalyces and a role for extracellular products in mediating pathological changes in amoebic gill disease.     

Uncertain and multi-objective programming models for crop planting structure optimization

Crop planting structure optimization is a significant way to increase agricultural economic benefits and improve agricultural water management. The complexities of fluctuating stream conditions, varying economic profits, and uncertainties and errors in estimated modeling parameters, as well as the complexities among economic, social, natural resources and environmental aspects, have led to the necessity of developing optimization models for crop planting structure which consider uncertainty and multi-objectives elements. In this study, three single-objective programming models under uncertainty for crop planting structure optimization were developed, including an interval linear programming model, an inexact fuzzy chance-constrained programming (IFCCP) model and an inexact fuzzy linear programming (IFLP) model. Each of the three models takes grayness into account. Moreover, the IFCCP model considers fuzzy uncertainty of parameters/variables and stochastic characteristics of constraints, while the IFLP model takes into account the fuzzy uncertainty of both constraints and objective functions. To satisfy the sustainable development of crop planting structure planning, a fuzzy-optimization-theory-based fuzzy linear multi-objective programming model was developed, which is capable of reflecting both uncertainties and multi-objective. In addition, a multi-objective fractional programming model for crop structure optimization was also developed to quantitatively express the multi-objective in one optimization model with the numerator representing maximum economic benefits and the denominator representing minimum crop planting area allocation. These models better reflect actual situations, considering the uncertainties and multi-objectives of crop planting structure optimization systems. The five models developed were then applied to a real case study in Minqin County, north-west China. The advantages, the applicable conditions and the solution methods of each model are expounded. Detailed analysis of results of each model and their comparisons demonstrate the feasibility and applicability of the models developed, therefore decision makers can choose the appropriate model when making decisions.     

澳大利亚棉花产业考察报告

通过对澳大利亚棉花产业考察,介绍了澳大利亚棉花生产及科研概况,包括植棉历史、植棉区域和气候、棉花品质、耕作制度、棉花农场、产业优势、棉花科研体系、棉花科技优势等内容。概述了澳大利亚棉花植棉特点,包括澳大利亚棉花种植模式、棉花品种、棉花灌溉及水资源管理、棉田土壤及施肥、病虫害及其防治、机械化、精准农业等内容。分析了澳大利亚植棉效益情况,包括植棉成本、澳棉纤维品质及棉花贸易。     

荔枝采摘机器人双目视觉的动态定位误差分析

扰动引起的随机误差成为采摘机器人视觉定位的难题。为了探索荔枝采摘机器人视觉定位误差,首先用双目视觉系统和模拟扰动的震动平台对荔枝结果母枝采摘点的三维坐标进行定位试验,检测其实际位置,获得误差数据;然后,提出了一种动态定位误差分析方法,根据误差变化规律将动态定位误差划分为系统误差和随机误差;最后,用统计方法对2类误差分别进行定量分析和评价。结果表明,定位距离为600~1 000 mm时,系统误差与动态定位误差的变化趋势基本一致,视觉深度方向、水平方向最大动态定位误差分别为58.8和17.3 mm。系统误差置信区间较窄,视觉深度方向系统误差与定位距离呈较强的线性相关性,水平方向则表现为非线性。扰动下的随机定位误差服从正态分布,视觉深度方向、水平方向间的随机误差相关性较弱。视觉深度方向受扰动的影响较大,随机误差远大于水平方向,且不确定度较高。研究结果为荔枝采摘机器人视觉定位系统校准和动态定位方案设计提供依据,为机构容错纠错提供理论依据和实践指导。