Residue Detection of Tetracyclines in Eggs by High Performance Liquid Chromatography

The study was aimed to establish the method of simultaneous detection of four kinds of tetracyclines,including oxytraoycline,tetracycline,chlortetracycline and doxyeycline in eggs by high performance liquid chromatography (HPLC).The eggs samples were detected with HPLC after through the procedure of extraction of 0.1 mol/L Na₂EDTA-Mcllvaine buffered solution,purification of Oasis MAX solid-phase extraction column,gradient elution of taking acetonitrile-0.01 mol/mL trifluoroacetic acid as mobile phase,separation with reverse liquid chromatography.The results showed that the calibration curves of four kinds of tetracyclines were linear correlated in the concentration range of 30 to 1 000 ng/g which the limits of detection was 10 ng/g and the limit of quantification was 50 ng/g.The average recoveries were 67.3% to 81.4%,relative standard deviations of intraday was 2.7% to 14.3%,relative standard deviations of inter-day was 0.9% to 5.0%.This mothod established in this study could simultaneously detect oxytetracycline,tetracycline,chlortetracycline and doxycycline drug residues in egg and it had high sensitivity,accuracy and precision.The method was rapid and simple to operate.     

Effect of Weaning Stress on Blood Physiology and Biochemistry Indexes and Immune Function in Dairy Buffalo Calves

To study the effect of weaning stress on dairy buffalo calves,5 healthy calves were chosen and weaned,and the blood samples were collected at 1 day before weaning,and 1,14 and 21 days after weaning to analysis blood physiology and biochemistry indexes and immune function.The results showed that the count of white blood cell,lymphocyte,erythrocyte,monocytes and hematocrit,aspartate aminotransferase activity,blood glucose,cortisol and immunoglobulin G contents of dairy buffalo calves were no significant difference between before and after weaning treatments (P > 0.05).The count of neutrophils at 21 d after weaning were significantly lower than that of 1 d before weaning of dairy buffalo calves (P < 0.05).However,lactate dehydrogenase and alanine aminotransferase activity in weaned treatments were significantly higher than those of animals in the treatment before weaning (P < 0.05).The serum urea nitrogen of dairy buffalo calves at 21 d after weaning was significantly higher than that of 1 d before weaning (P < 0.05) and hemoglobin content at 21 d after weaning was significantly lower than that at 1 day before weaning (P < 0.05).It indicated that the physiological and immunity function of dairy buffalo calves were challenged under weaning stress.     

Effects of Complex Nutritional Regulation Additives on Growth Performance,Slaughter Performance and Serum Biochemical Indexes of Grazing Sheep in Cold Season

This experiment was conducted to investigate the effects of complex nutritional regulation additives on growth performance, slaughter performance and serum biochemical indexes of grazing sheep in cold season.A single factor random block design was used and 48 grazing ewes with the average weight (28.01±1.70) kg and 7 months old were randomly divided into 4 groups:Group Ⅰ without supplement;Group Ⅱ with concentrate;Group Ⅲ with concentrate+complex formulation 1 (0.30% malic acid, 0.06% cysteamine, 0.08% saccharicterpenin);Group Ⅳ with concentrate+complex formulation 2 (0.60% malic acid, 0.12% cysteamine, 0.16% saccharicterpenin)with 3 replicates per group and 4 grazing ewes per replicate.The results showed that:①The final weight of group Ⅲ was the highest and higher than group Ⅱ and Ⅳ by 6.26% (P>0.05)、3.69% (P>0.05), respectively.The average daily gain of group Ⅲ was highest, and higher than group Ⅱ and Ⅳ by 26.32% (P<0.01)、5.74% (P>0.05) respectively.②Comparing with group Ⅱ, the slaughter rate of group Ⅲ was increased by 4.68% (P>0.05).Compared with groupⅠ, Ⅱ and Ⅳ, the meat percentage of group Ⅲ was increased 18.46% (P<0.05), 10.97% (P>0.05) and 4.40% (P>0.05), while the net meat weight of carcass in group Ⅲ was increased by 49.74% (P<0.01), 13.22% (P>0.05) and 18.27% (P<0.05), respectively.Compared with groupⅠ, Ⅱ and Ⅳ, the net meat rat of carcass in group Ⅲ was increased 10.42% (P<0.01)、6.00% (P>0.05) and 3.37% (P>0.05), respectively.③There was a rising trend as the order of groupⅠ, Ⅱ, Ⅳ and Ⅲ in serum glucose, Ca, P, HDL, LDL, GPT and IgG, while A/G and TG showed a decreasing trend.Based on the above results, in this trial, supplementing complex nutritional regulation additives had good effects on growth performance, slaughter performance and serum biochemical indexes of grazing sheep in cold season.And supplementing complex formulation group 1 (group Ⅲ) was the best.     

鞭毛素fliC基因的缺失对肠炎沙门氏菌生物膜形成的影响

为研究肠炎沙门氏菌鞭毛素对其生物膜形成的影响,本研究利用构建的肠炎沙门氏菌鞭毛素编码基因fliC缺失株,检测其缺失性修饰后的生长表型变化及其对生物膜形成的影响。结果显示在表型检测试验中,fliC缺失株在电镜下观察呈无鞭毛形态,在半固体培养基上缺乏运动性,并且不能与肠炎沙门氏菌鞭毛单克隆抗体发生可见的凝集反应。生物膜形成能力定性试验结果表明,肠炎沙门氏菌fliC缺失株生物膜形成大量减少,并且生物膜脆弱,而其回补株能够较好地恢复生物膜的形成;生物膜定量结果进一步证明,鞭毛素fliC基因缺失后肠炎沙门氏菌形成生物膜的能力下降50%左右,以上结果显示鞭毛在肠炎沙门氏菌体外生物膜形成中具有重要作用。     

达乌尔黄鼠线粒体Cyt b基因序列特征及其系统进化分析

在甘肃省天祝藏族自治县采集12只达乌尔黄鼠(Spermophilus dauricus),PCR产物直接测序获得Cyt b基因1140bp序列,采用Clustal X 1.84、MEGA 6.0、Dna SP 5.0等生物信息学软件进行了序列特征和系统地位分析。结果显示,达乌尔黄鼠Cyt b基因含116个多态信息位点,群体中多态位点类型有转换、颠换,Cyt b基因T,C,A,G碱基含量分别为33.7%,25.9%,27.6%,12.9%。基于Kimura双参数的遗传距离显示,属内种间大黄鼠(Spermophilus major)与新疆黄鼠(Spermophilus fulvus)间遗传距离最小(0.034),高加索黄鼠(Spermophilus musicus)与达乌尔黄鼠最大(0.172),达乌尔黄鼠群体内遗传距离为0.140,种群分化较大,基于NJ法构建的系统进化树符合传统分类标准,研究为达乌尔黄鼠Cyt b基因标记的种群遗传学应用提供了参考。     

基于逻辑回归的植物新品种权质量评估研究——以杂交水稻品种权为例

随着植物新品种权的申请授权量急剧增长,品种权的"数量多、质量差"的问题引起了全社会的普遍关注。如何评价品种权质量成为重要的理论和现实问题。为了科学合理地判断我国品种权的综合质量水平,首先从竞争力的角度界定植物新品种权质量的定义,然后从品种权的法律、技术和经济三大属性建立品种权质量评价指标体系,并利用均值差异法验证品种权质量指标的有效性,最后采用逻辑回归模型构建品种权质量综合指数,以便全面、快捷地综合评价品种权质量。植物新品种权质量评估研究不仅有利于解决品种权质量判断标准问题,对提高品种权质量水平提供了理论依据,而且为我国品种权的价值评估、许可转让、融资、抵押等交易活动提供重要参考。     

影响‘小凤兰’根状茎增殖、分化和壮苗的因素研究

以‘小凤兰’根状茎为试材,研究了影响‘小凤兰’根状茎增殖、分化、生根壮苗的因素。结果表明:MS基本培养基、蔗糖30g/L、6-BA 2.0mg/L+NAA 0.5mg/L、活性炭0.5g/L有利于根状茎增殖,而添加20%椰汁和番茄汁40g/L会抑制根状茎增殖。1/2MS基本培养基、蔗糖30g/L、6-BA 2.0mg/L+NAA 0.2mg/L、20%椰汁、1 000lx光照强度有利于根状茎分化,不加活性炭有利于芽分化,但抑制根分化,而添加活性炭则抑制芽分化,促进苗分化。添加土豆泥60g/L显著促进试管苗生长,3~4cm高的苗在培养基1/2MS+6-BA 0.1mg/L+NAA0.5mg/L+蔗糖20g/L+土豆泥60g/L+卡拉粉8g/L+活性炭0.5g/L中培养40d即可移栽。     

武汉地区梨瘿蚊生物学特性及其种群动态变化研究

以梨瘿蚊为研究对象,采用显微观察及田间统计方法,调查了梨瘿蚊的危害症状,梨瘿蚊卵、幼虫、成虫的形态特征及其产卵习性等生物学特性,系统研究了梨瘿蚊成虫种群和幼虫种群动态变化及梨园天敌昆虫的动态变化。结果表明:梨瘿蚊在湖北省梨产区1年发生3代,越冬代成虫羽化出土时间周期较长,从2月下旬出土,一直持续到3月下旬羽化达到高峰,梨瘿蚊幼虫种群在1年中出现3次危害高峰,危害高峰在梨瘿蚊成虫羽化后20~30d后出现;当环境温度高于30℃时,梨瘿蚊幼虫结茧化蛹,不再羽化;梨园中梨瘿蚊的天敌昆虫的种类主要包括草蛉、异色瓢虫、龟纹瓢虫、食蚜蝇、蜘蛛和蚂蚁等。     

濒危植物羽叶丁香组织培养

以濒危植物羽叶丁香的芽和种子为外植体,采用植物组织培养法,研究了不同消毒方法对无菌体系建立、不同浓度的蔗糖和激素组合对种子初代培养、不同基本培养基和激素组合对增殖和生根的影响,以期为羽叶丁香的组培快繁、种质资源保护和开发利用提供依据。结果表明:新枝为较适宜的外植体,适宜的消毒方式为75%酒精消毒30s,0.1%升汞消毒7min,最适增殖培养基为MS+5.0mg·L~(-1) 6-BA+0.01mg·L~(-1) IBA;最适种子初代培养基为MS+20g·L~(-1)蔗糖汁+3.0mg·L~(-1) 6-BA+0.10mg·L~(-1) IBA,最适增殖培养基为MS+7.0mg·L~(-1) 6-BA+0.05mg·L~(-1) IBA;最适生根培养基为WPM+2.0mg·L~(-1) IBA。