鸡毒支原体和大肠杆菌混合感染病例的实验室诊断

报道了一例鸡毒支原体和大肠杆菌混合感染病例的实验室诊断。应用细菌学方法无菌取肝脏和关节肿疱液接种鲜血琼脂培养基进行细菌分离,挑取鲜血琼脂培养基上均一生长的菌落划线接种于麦康凯斜面用于细菌鉴定,将分离的大肠杆菌涂布鲜血琼脂培养基进行药敏试验。取关节肿疱液接种KM2液体培养基,取关节肿疱液及其不同代次的KM2培养物进行支原体PCR检测。结果从发病鸡肝脏中分离到大肠杆菌,该菌株对丙氟哌酸、氟苯尼考等药物敏感;从关节肿疱液及其1～3代KM2培养物中均扩增出鸡毒支原体的基因片段;说明该群病鸡发生了鸡毒支原体和大肠杆菌的混合感染。     

五种常用药物对江黄颡鱼幼鱼的毒性试验

在pH7．6、溶氧为5mg／L以上、21-26℃的静水条件下,采用生物毒性试验方法进行高锰酸钾、福尔马林、食盐、硫酸铜、敌百虫等5种常用药物对江黄颡鱼幼鱼的急性毒性试验。结果显示,各药物的24hLC30、48hLC50、SC分别为：高锰酸钾5．49、5．18、1．39mg／L;福尔马林63．15、59．54、15．95mg／L;食盐9436、8945、2418mg／L;硫酸铜1．87、1．81、0．51mg／L;敌百虫5．74、5．00、1．14mg／L。依据各药物对江黄颡鱼幼鱼48hLC撤大小排列,其毒性大小依次为：硫酸铜〉敌百虫〉高锰酸钾〉福尔马林〉食盐;各药物对江黄颡鱼幼鱼SC大小依次为：硫酸铜〈敌百虫〈高锰酸钾〈福尔马林〈食盐。     

Spatial analysis of yield monitor data: case studies of on-farm trials and farm management decision making

A 3-year case study was undertaken of how North American farmers use yield monitors for on-farm trials in farm management decision making. Case study methods were used because relatively few farmers quantitatively analyze yield monitor data. At this early research stage, insufficient farm management information about the data was available to ask the right questions in a large-scale survey. In addition to the formal case study of farmers experienced at using yield monitors to collect on-farm trial data, the study evaluated the effect of yield monitor data quality on farm decisions. Two levels of yield data quality included standard output where the default settings of farm-level mapping software were accepted and where filtering of the data was undertaken. Results indicated that yield data quality affects farm management decisions. In addition, farmers receiving a spatial analysis of their on-farm trial data tended to use split-field designs instead of replicated split-planter designs. They were also more confident in their decisions than before participation in the spatial analysis project, and made decisions more quickly.     

葡萄抗病性研究进展

目前葡萄抗病研究主要采用田间自然发病调查和人工接种2种方法，病毒病用免疫学、分子生物学和传统生物学检测。葡萄抗病性分级标准有反应型和严重度2种标准。葡萄抗病性与品种、氮代谢、酶活性变化和叶绿素有显著相关，但与物质代谢、叶幕结构的相关性目前还存在歧义。防治技术主要是选用抗病品种、加强测报、及时喷药。     

油菜高产栽培的肥料效应研究

采用"3414"肥料效应试验方案,研究了安徽省东至县油菜高产栽培的氮、磷、钾肥肥料效应,并建立了肥料效应函数模型.结果表明:项目区土壤氮、磷、钾供给能力达中等偏上水平,增施磷肥有利于提高油菜产量,而增施氮和钾肥增产效应并不显著;最佳经济施肥量为N 24.53 kg/hm2、P2O577.65 kg/hm2和K2O 4.66 kg/hm2.     

基层土肥化验室履行公益性职能综述

河南省汝州市土肥化验室仪器精良,检测能力先后通过河南省土肥站、中华人民共和国农业部考核验收,具备履行土壤肥料质量检测这一公益性职能的能力。为充分发挥化验室的作用,促进农业新技术的推广和应用,提出了主要的保证措施。     

桓仁县玉米施肥指标体系研究

测土配方施肥技术是促进农业节本增效的重要途径。通过在辽宁省桓仁县进行玉米的"3414"田间试验,初步建立桓仁地区玉米肥料效应函数方程,得出最佳产量及其施肥量,为当地玉米生产的合理施肥提供科学指导。     

Factors in making fertilizer recommendations

Abstract

In situ elemental distributions and shifts were determined in basipetal root and stem tissues of tomato by x‐ray fluorescence. Some significant elemental distributions and shifts occurred in the tissues and organs. Fe, Cu, Zn, Rb, and Sr concentrated in the root and Br in the stem. Cortical tissues concentrated Fe, whereas vascular tissues concentrated Cu and Zn. Most of the Cl, Br, and Sr concentrated in the phloem—Br in the stem phloem, Sr in the root phloem, and Cl evenly distributed in the phloem of both organs. A positive Rb‐Sr association was unique for cortical tissue of both organs, and a positive Ca‐Sr association was characteristic of the xylem of both organs. Mutual elemental associations characterized transport and distribution of the elements in the tissues.     

尾叶桉(Eucalyptus urophylla)杂种家系遗传测定及抗风选择

中国华南沿海地区台风影响频发,为选育桉树抗风和速生品种,本研究估算广东鹤山9年和11.5年生56个尾叶桉家系(含母本和对照)生长、抗风等性状的杂种优势、育种值及配合力。结果表明:两个不同年度各性状在杂种家系间存在极显著差异。以单株蓄积为指标筛选优良杂交组合,两个年度均排名前3的是37号和40号,分别是家系128号9年生平均0.207 9 m^3和11.5年生0.336 9 m^3的1.33和1.79倍以及1.28和1.52倍,11.5年生超过128号的家系共6个,6个家系平均超亲优势达到15.99%;两个年度单株蓄积育种值均超过0.05且抗风性育种值为正的仅4个家系;以11.5年生调查数据和最优56号家系为选择标准,超过其平均单株蓄积0.345 7 m^3和抗风等级值4.33的杂种单株有173株。本研究发现,2号、15号、21号、22号、和64号是具有较高母本一般配合力的亲本,而2号、21号、22号、29号和56号这5个父本的一般配合力较高,通过优化组合可获得具有优良性状的子代;生长结合抗风指标选择到的3个特殊配合力高的杂交家系和173株优株,是今后高世代育种重点利用对象,也可为台风区人工林建设提供更多资源产品。     

Retrospective Identification of Bacterial Isolates From Emergency Laparotomy Surgical Site Infections in Horses

Surgical site infection (SSI) with multiresistant bacteria is an important cause of postoperative morbidity after laparotomy in horses. The objective of this study was to identify bacteria isolates and their antibiotic resistance patterns associated with the development of wound infection in horses after laparotomy. This is a retrospective case series. Medical records of horses that underwent ventral midline exploratory laparotomy in a four-year period at one equine hospital were reviewed. Results of microbiologic culture and susceptibility testing are described. The study group consisted of 183 (100%) horses that recovered from anesthesia after laparotomy. The prevalence of infection was 19% (24/124) after first surgery and 83% (19/23) after relaparotomy. The most common microbial isolates were bacteria of the family Enterobacteriaceae followed by Staphylococcus ssp., Enterococcus ssp., Streptococcus ssp., and Bacteroides ssp. Bacteria from the family Enterobacteriaceae showed the lowest resistance to amphenicols, cephalosporins, and quinolones groups of antibiotics. Coagulase-positive Staphylococci were sensitive to amphenicols and only 33% were resistant to trimethoprim/sulfamethoxazole. The most commonly used perioperative and postoperative antibiotics were gentamicin and amoxicillin. Limitations include poor control over exposure factors, covariates, and potential confounders during the surgery, recovery time, or period of hospitalization; relying on others for accurate outcome assessment and recordkeeping; lack of follow-up information once animals were discharged from the hospital. Despite 5 days of antibiotic prophylaxis, the rate of incisional infection is still high. The most common isolates from SSI belong to the family Enterobacteriaceae and the genus Staphylococcus, which showed high resistance to the antibiotics used before the gastrointestinal surgery.