奶牛多杀性巴氏杆菌病诊断和防治建议

临床上,呼吸道疾病对牛群的危害较为严重。为明确某牛场断奶牛群呼吸道疾病的发病原因,指导疾病的预防和治疗,采集了病死牛的病料样品,进行了病原学检查和鉴定。经细菌分离培养、涂片镜检、PCR和生化鉴定,确定分离菌株为多杀性巴氏杆菌,分别命名为PM1和PM2。致病力试验结果显示,两株细菌对接种小鼠均具有致死性。药敏试验结果显示分离株对头孢类药物、环丙沙星和左氧氟沙星等高度敏感,可为临床用药提供参考。     

农作物单倍体育种研究概况与思考

介绍了单倍体的获得途径和育种价值,分析了国内外单倍体育种成绩与进展,介绍了山东省小麦、玉米、棉花、花生、蔬菜等主要农作物单倍体育种概况,并提出了发展单倍体育种的建议。     

Understanding local agri-food systems through advice network analysis

Agri-food clusters have generated great interest in recent years and prompted a new wave of research dedicated to ‘Localized Agri-Food Systems’ (SYALs in French). However, the specific nature of relations between firms who belong to SYALs has rarely been studied. Our purpose is to show how the analysis of company directors’ advice networks helps to better understand the specificity and innovative dynamics of SYALs. Our research was based on a case study in the Biterrois wine growing region of southern France. We conducted a survey to collect information on advice relations between wine cooperative managers, who play a key role in the innovation process toward quality wine. Sociometric analysis of the advice relations, coupled with interviews, led to three main results: the first was that managers simultaneously cooperate on technical projects and compete for business ends. The second was a correlation between the innovations implemented by the cooperatives and the degree of centrality of the managers in the networks, revealing the relational and local conditions of innovations in SYALs. The third was that managers can modify their own network to improve the competitiveness of both their own cooperative and of the SYAL as a whole. In conclusion, we show that advice network analysis is an appropriate tool to describe the relational dimension of SYALs, to better understand their process of innovation, and to help managers improve the collective strategies they apply within the SYAL.     

中长绒陆地棉发展现状及品种选育的思考

中长绒棉的选育和应用已成为棉花产业发展的重要趋势,本文主要介绍了我国中长绒棉的育种发展现状、存在的问题及育种方向。