一例猪繁殖与呼吸综合征的RT-PCR诊断与防制

2008年3月,新乡市某猪场发生了以一种经产母猪和初产母猪流产、死产、产木乃伊胎、死胎及弱仔为特征的疾病。采集流产胎儿和死胎的肺、肝、脾脏等病料,制悬液,取上清,进行细胞培养,观察细胞病变。另根据猪繁殖与呼吸综合征病毒美洲株VR-2332 ORF7基因序列设计一对特异引物,提取流产胎儿的肺、肝等组织中PRRSV的RNA,经RT-PCR扩增,检测猪繁殖与呼吸综合征病毒为阳性,结合病史和临床症状,诊断为猪繁殖与呼吸综合征。通过对该猪场采取紧急接种疫苗、彻底消毒等综合防制措施,控制了该病的流行与蔓延。     

Effect of incubation temperature regimes and culture medium on broccoli microspore culture embryogenesis

Conditions for reliable induction of embryogenesis from isolated microspores were studied in ten genotypes of broccoli. Embryo yields were significantly increased in almost all of the broccoli genotypes by the incubation at 32.5 ^°C for 1 day, than when the standard incubation at 30 ^°C for 2 days was used. Treatments of 48 hours at 32.5 ^°C produced less than optimal results suggesting that broccoli microspores are more sensitive to high temperatures than those of B. napus. The use of the ¹/₂ NLN-13 medium yielded greater number of embryos than the standard NLN-13. The magnitude of the response to the redution of the concentration of major salts by half in the NLN medium varied with the different genotypes. High embryogenic broccoli cultivars, such as ‘Shogun’, ‘SDB9’, and ‘Green Valiant’, presented a better response to the reduction of the concentration of major salts by half in NLN-13. Reduction never produced a detrimental effect on embryo yield and seems not to have any effect in the subsequent development of embryos in plants. This revised version was published online in July 2006 with corrections to the Cover Date.     

4个台湾青枣品种的组培技术研究

以种植于大棚内的4个台湾青枣品种2年生嫁接苗嫩梢作外植体,进行了外植体表面灭菌,在培养基中添加不同浓度6-BA、IBA、KT、NAA激素的启动、分化、生根培养的组培技术研究。结果表明:台湾青枣嫩梢外植体表灭菌,用0.1%HgC l2消毒液二次灭菌的效果为好,其组培适宜的外植体为一年生健壮枝条的茎尖和带腋芽的茎段,4月份为最佳的采集时间。台湾青枣4个品种(五千种、黄冠、高朗一号、蜜枣)最适的启动培养基均为MS 6-BA1.0 mg/L IBA0.1 mg/L。分化培养基则存在显著差异,不同品种拟选用不同的培养基;台湾青枣普遍存在组培苗生根困难的问题,其"五千种"组培的适宜生根培养基为:1/2MS IBA0.2 mg/L NAA0.4 mg/L。     

甜叶菊组织培养条件的研究Ⅱ.不同基本培养基、不同碳源对愈伤组织形成及芽诱导的影响

以MS为基本培养基进行甜叶菊组织培养 ,培养物生长速度快 ,分化频率高 ;以蔗糖作碳源的培养物 ,其愈伤组织诱导率、出芽率均比葡萄糖、麦芽糖作碳源的高。     

基于柯布-道格拉斯生产函数的中国罗非鱼池塘养殖经济效益及影响因素分析

为了分析罗非鱼养殖经济效益的影响因素,采用2014年广东、广西、海南、福建和云南等5省（自治区）12个县的300组调查数据,运用成本收益分析法对罗非鱼池塘单养、混养和综合经营模式的经济效益进行了统计分析,并通过柯布-道格拉斯生产函数模型,测算了不同的投入和产出因素对中国罗非鱼池塘养殖经济效益的影响程度。结果表明,罗非鱼综合经营模式的成本利润率最高,罗非鱼单养模式的成本利润率最低。罗非鱼养殖生产的饲料投入、罗非鱼劳动用工数和池塘养殖面积因素是影响罗非鱼养殖效益的最显著因素。提出进行健康生态养殖,提高罗非鱼产品质量、降低饲料系数,提高饲料利用率、成立产业化经营组织和发展电子商务等途径来提高中国罗非鱼池塘养殖的经济效益。     

薄荷的快速繁殖与栽培技术的研究

本文介绍了薄荷的特性、栽培技术及用途，表明它在我们日常生活中起着重要的作用。用薄荷的组织培养方法可加速其繁殖系数，以达到迅速应用的目的。     

基本培养基和蔗糖浓度在大白菜花药培养中对胚状体诱导的影响

以6个大白菜品种为试材进行花药培养,研究了不同基本培养基和蔗糖浓度对胚状体诱导的影响。结果表明,B5和Keller培养基为适适宜的基本培养基;培养基适宜的蔗糖浓度为8％-12％,最适浓度为10％。     

大姚核桃经济价值及培育技术探讨

文章分析了大姚核桃的经济价值,并从营建原则、栽植要领、土壤管理、肥料管理、水分管理和健康护理方面论述其培育技术。     

Effect of Western Architectural Culture on the Traditional Dwellings in Meizhou

Under the special social background and source of history, the western architectural culture affected the traditional dwellings in Meizhou from the 19th century till the 20th century. The framework, outline and materials of traditional dwellings were changed in certain extent while the form of plane layout and interior decoration still stood stable maintaining the native characters. This article analyzes the phenomena of incorporation of things with diverse nature.     

园林地被植物连钱草的组培繁殖试验

针对黑龙江省耐阴植物连钱草开展组培快繁试验,结果表明:连钱草在设计的几种培养基中均能繁殖、分化;筛选出增殖培养基1/2MS+BA1mg·L-1+NAA1mg·L-1和生根培养基1/2MS+NAA0.1mg·L-1+IBA0.1mg·L-1两个培养基,并在蛭石+草炭土+珍珠岩1∶1∶1的基质中移栽生长良好。