中西结合治疗216例犬细小病毒病疗效观察

通过临床症状、流行病学特点和犬细小病毒抗原试剂盒对疑似细小病毒感染的216例病犬进行确诊,并对确诊为细小病毒感染的部分病例进行抗体水平检测,以判断其预后,采用中西结合的综合措施治疗发病犬,治愈率达到70%,提出了有效的预防措施。     

高致病性猪繁殖与呼吸综合征的诊断与防治

高致病性猪繁殖与呼吸综合征是由PRRSV变异株引起的一种急性高致病性传染病,近些年给养猪业造成巨大的损失。文章就高致病性猪繁殖与呼吸综合征的最新流行特点、诊断、防治等方面予以介绍。     

设施土壤连作障碍电处理试验研究

连作障碍是设施农业生产中的常见问题,严重影响着作物的产量和品质。目前,设施土壤连作障碍一般采用施肥或施药等化学方法对土壤进行消毒处理,但这样会造成土壤环境的二次污染,而利用电处理技术对土壤进行物理处理会避免这一问题。从土壤理化性质着手,以土壤中氮、磷、钾等营养元素含量为指标,通过试验研究及方差分析,验证电处理技术对土壤元素含量的变化有着显著的作用。     

长春花感染柑橘黄龙病菌微波热处理防控效果

为探索黄龙病防治途径,开展微波热处理对黄龙病的防控效果研究。该研究搭建了微波热处理平台,对长春花微波热处理参数（转盘转速、单个磁控管的微波功率、磁控管数量）进行优化,并用优化后的参数组合对感病长春花进行热处理,处理后90 d内跟踪检测长春花叶片中黄龙病菌的浓度、淀粉和类黄酮的含量。结果表明,长春花微波热处理的最优参数组合为单个磁控管的微波功率150 W、3个磁控管、转速15 r/min;热处理90 d后,感病长春花叶片中的黄龙病菌Ct值（阈值循环数,该值低于32时为阳性）由阳性(17.01±0.97)转至近阴性（31.91±2.35）,病菌浓度下降了99.98%,淀粉含量和类黄酮含量恢复至正常水平,植株的活性恢复较好。研究表明,微波热处理有效抑制植物体内的黄龙病菌,可为黄龙病的规模化防治提供新思路。     

老化玉米种子修复处理后的活力效应研究

以玉米自交系Mo17种子为试材,对不同老化水平的玉米种子进行氯化钙(CaCl2)、抗坏血酸(AsA)、聚乙二醇(PEG)、青霉素(Penicillin)和赤霉素(GA3)修复处理。结果表明,500 mg/L AsA对Mo17老化玉米种子的活力修复效果明显;0.015 mg/LCaCl2对不同老化程度的玉米种子修复范围较宽,修复作用较好;100 mg/L Penicillin处理只对中活力玉米种子有修复作用;500 mg/L GA3对不同老化程度玉米种子的修复作用不明显;20%PEG处理对老化玉米种子没有修复作用,且加速了高活力种子的活力衰退。500 mg/LAsA处理老化玉米种子其修复效应明显,修复作用比较温和,在生产中能提高发芽率70%以下的玉米种子活力,是较为理想的修复剂。     

甘蔗温水脱毒健康种苗田间栽培增产效果

选用ROC22、粤糖82-882、粤糖83-88和粤糖93-159四个主栽品种进行甘蔗温水脱毒健康种苗与常规种苗田间种植对比试验研究,结果表明:甘蔗温水脱毒健康种苗较常规种苗能普遍改善甘蔗农艺性状,提高甘蔗产量和糖分,增产效果明显,其二级健康种苗效果优于一级健康种苗。     

滴灌灌水器流道堵塞及防治研究进展

滴灌的堵塞问题一直是困扰滴灌技术应用与发展的限制性因素,为了探索解决或者预防该问题的技术途径,从堵塞的成因、机理以及预防措施等方面进行了论述,提出了预防灌水器堵塞的基本措施,包括改进灌水器流道结构、强化水质处理以及严格过程管理。在此基础上,对今后的重点研究方向提出了若干建议。     

Susceptibility of Caspian Roach (Rutilus rutilus caspicus) Fingerlings to Formalin

ABSTRACT

Caspian roach (Rutilus rutilus caspicus) were exposed to 0, 30, 40, 45, 50, 55, 60, 70, 100, 150 200, 250, 300, and 400 ppm formalin to determine LC₅₀. Respectively, 0.5 to 96 h LC₅₀ values were 252 to 49 ppm. The lowest observed effect concentrations (LOEC) and no observed effect concentrations (NOEC) varied between 40 to 150 and 30 to 100 ppm, respectively, across the tested time spectrum. Regression suggested that the concentrations of 88.4, 80.3, 51.2, and 40.1 ppm are maximum concentrations for 0.5, 1, 12, and 24 h bath treatment, respectively, which are not in the range suggested in the literature.     

Biochemical Properties and Stability of Antioxidative Activity of Half-Fin Anchovy (Setipinna taty) Fermented Product

The aim of this work was to investigate the biochemical properties of fermented product of half-fin anchovy (HAFP; Setipinna taty) made by Natto bacillus fermentation—including molecular weight distribution, amino acid composition, solubility, foaming, and emulsifying profiles. Furthermore, the influences of thermal processing, pH alteration, and in vitro simulated gastric and intestinal digestion on the antioxidative stability of HAFP in terms of the scavenging 1,1-diphenyl-2-picrylhydrazayl (DPPH) radical were evaluated. Results showed that HAFP contained small peptides (< 1,500 Da) and free amino acids. The amounts of essential amino acids and flavor amino acids were 155.219 and 178.636 mg/g of dry HAFP, respectively. Moreover, HAFP contained high levels of antioxidative and hydrophobic amino acids. In suitable pH values, HAFP exhibited good solubility, foaming, and emulsifying properties. The antioxidative activity of HAFP on the scavenging DPPH radical increased after thermal processing. Furthermore, the DPPH radical scavenging activity of HAFP was enhanced slightly or dramatically after being treated under pH values from 3 to 6, or in vitro simulated gastric and intestinal digestion. It can be concluded that HAFP could have potential application in foods as a natural antioxidative ingredient.     

Effects of different bronopol treatments on final survival rates in the artificial incubation of crayfish eggs (Pacifastacus leniusculus,Astacidae)

Two experiments were conducted on the effects of bronopol in the artificial incubation of crayfish eggs (Pacifastacus leniusculus) with the aim to search an alternative to formaldehyde. In the first experiment, 50, 250, 500 and 1000 ppm bronopol and 3000 ppm formaldehyde (control) in periodical administrations were tested on a density of 6.6 eggs cm^?2. After 44 days of incubation, the highest survival was obtained with 1000 ppm bronopol (81.9% to stage 2 juvenile, with no significant difference from formaldehyde), whereas lower bronopol concentrations resulted in significantly lower survival. In the second experiment, 1000, 3000 and 5000 ppm bronopol and 3000 ppm formaldehyde (control) administered for 15 min every second day were tested on eggs at a density of 20 eggs cm^?2. After 78 days of incubation, bronopol at 3000 ppm allowed for a stage 2 juvenile survival rate of 65.0% (with no significant difference from formaldehyde), whereas significantly lower survival was obtained with 1000 ppm or 5000 ppm. This study shows that bronopol may constitute an alternative to formaldehyde in the artificial incubation of crayfish eggs. A concentration of 3000 ppm administered for 15 min every second day may be adequate even on long incubations at high densities (at least 20 eggs cm^?2, one complete layer).