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211.
212.
同许多种其它果树一样,山植属的Crataegus grayana也可应用组织培养的方法,进行快速繁殖。在加入0.25ppmBA,0.5ppmIAA以及150ppm水解干酪素的MS培养基上,可由胚得到实生苗。在加入0.5ppm和300ppm水解干酪素的MS培养基上,由茎尖与茎段可得到壮实的试管苗。由于该植物胚在第一年内成熟度甚低,因此用茎尖或茎段进行快繁殖远优于用胚来进行。从此项研究结果看,其繁殖率为2~n-3~n(n为∮月数)。 相似文献
213.
宰后检验是整个肉品卫生检验工作中的重要环节,是宰前检疫的继续和补充。“四部”制定的《肉品卫生检验试行规程》和国家国内贸易局制定的《肉品品质检验规程》都明确规定必须进行心、肝、肺检验,它是宰后检验的重要组成部分和主要着眼点之一。这些卖质器官的检验可以作为我们综合判检的主要依据。另外,我国广大人民群众比较喜食内脏器官,这更要求我们对心、肝、肺进行严格的检验,防止食肉中毒,防止畜禽疫病传播,防止人畜共患传染病。1 心脏l.1心脏检验 四部规程规定“检查心包及心肌并沿动脉管剖检心室及心内膜,同时注意血液… 相似文献
214.
本实验建立了饲料中有机氯农药(OCPs)残留的气相色谱-微池电子捕获检测器(GC-μECD)分析方法。试样经丙酮提取,硅胶层析柱净化后,用GC-μECD测定其中农药残留量。有机氯农药浓度在5.00~500.00ng/mLp,p’-DDD相关系数除为0.9960外,其余均大于0.998,线性关系良好;检测限除o,p’-DDT和p,p’-DDT为10μg/kg外,其余农药为5μg/kg;添加有机氯农药50μg/kg水平时回收率为77.1%~113.4%,添加200μg/kg时回收率为75.8%~107.3%;相对标准偏差为2.3%~11.1%。本方法对饲料中有机氯农药残留分析结果准确可靠。 相似文献
215.
从2003年10月至2004年6月,在河北、辽宁、山东等地区鸡群中大规模发生以神经症状、肠道出血为主的流行性疾病。本文对从河北省某AA肉鸡场的病死鸡中分离的病毒毒株,经过实验室的系统鉴定,证实该分离株具有血凝性,且可被ND标准阳性血清所抑制和中和,不能被AI(H5亚型与H9亚型)标准阳性血清及阴性血清抑制;该分离株的毒价为109.3ELD50/0.1ml,MDT为57.6h,ICPI为1.89,IVPI为2.62,回归试验鸡的临床表现与自然病例基本一致。试验结果证明,该毒株属于嗜神经型新城疫病毒强毒株,并命名为Q-BS株。 相似文献
216.
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Qaisar Shahzad Muhammad Waqas Liping Pu Armughan Ahmed Wadood Long Xie Asma Ul Husna Kailin Yang Jingyuan Wang Huiyan Xu Kehuan Lu Yangqing Lu 《Reproduction in domestic animals》2020,55(9):1115-1123
Buffalo is considered short-day breeder in tropical and subtropical part of the world and seasonality and photoperiodism impart major influence on its fertility. However, its impact on in vitro embryo production (IVEP) remains elusive. Therefore, this study investigated the effect of seasonal variations and photoperiodism on morphological and molecular parameters of IVEP in buffalo. For this purpose, we conducted two different experiments on the oocytes obtained by aspirating follicles from abattoir derived ovaries. In Exp. I, retrospective analysis was performed for oocyte recovery, blastocyst and hatching rate, during four consecutive seasonal periods (i.e. January–March, April–June, July–September and October–December). In Exp. II, oocytes from peak breeding and non-breeding seasons were subjected to 24 hr in vitro maturation and evaluated for polar body extrusion to assess maturation rate. Results showed that embryo development was markedly low during second quarter (April–June) and maximum during fourth quarter (October–December) of the year; referred as non-breeding and breeding seasons, respectively. Comparative data analysis demonstrated that poor oocyte quality is major reason for lesser efficiency of embryo production during non-breeding season than peak breeding season as suggested by poor oocyte recovery (2.31 ± 0.10 vs. 3.65 ± 0.27) and maturation rate (33.32 ± 2.1 vs. 63.15 ± 7.31). Subsequently, comparative gene expression analysis of blastocysts during peak breeding season significantly upregulated pluripotency gene (OCT-4) and downregulated heat shock protein 90, as compared to non-breeding season. Therefore, it could be divulged from the present study that seasonal variations and photoperiodism have profound effect on oocyte quality and subsequent embryo development. It is recommended to find suitable additives for in vitro maturation that could mitigate seasonal effects. 相似文献
218.
Comparative pharmacokinetics and tissue distribution of quinocetone in crucian carp (Carassius auratus), common carp (Cyprinus carpio L.), and grass carp (Ctenopharyngodon idella) following the same experimental conditions 下载免费PDF全文
F. Wang H. Yang N. Xu Q. Yang 《Journal of veterinary pharmacology and therapeutics》2015,38(4):383-391
The pharmacokinetics and tissue distribution of quinocetone (QCT) in crucian carp (Carassius auratus), common carp (Cyprinus carpio L.), and grass carp (Ctenopharyngodon idella) were compared after oral administration of QCT (50 mg/kg body weight) at water temperature of 24 ± 1 °C. Similar QCT plasma concentration–time profiles were found in the three species of cyprinid fish at the same dosage regimen and water temperature, which were all fitted two‐compartment open pharmacokinetic model. However, different pharmacokinetic parameters were observed in crucian carp, common carp, and grass carp. The absorption rate constants (Ka) of QCT were 1.65, 1.40 and 1.74/h, respectively and absorption half‐lives (t1/2kα) were 0.42, 0.49, and 0.40/h, respectively. The distribution half‐life (t1/2α) was 2.83, 0.67, and 0.88 h, respectively, and elimination half‐lives (t1/2β) of QCT were 133.97, 63.55, and 40.76 h, respectively. The maximum concentrations (Cmax) of QCT in plasma were 0.315, 0.182, and 0.139 μg/mL and the time to peak concentrations (Tp) were 1.45, 0.96, and 1.08 h, respectively. The area under the plasma concentration‐time curves (AUC) were 12.35, 5.99, and 4.52 μg·h/mL, respectively. The distribution volumes (Vd/F) of QCT were calculated as 117.81, 128.71, and 220.10 L/kg, respectively. The tissue analysis showed that a similar regularity was obtained in the three species of cyprinids with a single dose of 50 mg/kg body weight after oral administration at the same water temperature. The tissue concentration of QCT in each fish was in order of liver>kidney>muscle, while the residues of QCT in the three species of cyprinid fish were in order of crucian carp>common carp>grass carp. 相似文献
219.
为揭示鄱阳湖湿地苔草群落的构建机制,选择灰化苔草(Carex cinerascens)群落作为研究对象,通过设立3条样带调查不同水分梯度的群落物种多度,选用断棍模型(BSM)、生态位优先占领模型(NPM)、优势优先模型(DPM)、随机分配模型(RAM)和生态位重叠模型(ONM)5个生态位模型对群落种-多度关系进行拟合,结果表明,1)灰化苔草群落可按土壤水分划分为高湿度、中湿度和低湿度3组,分别对应从湖边、湿地中间和湿地边缘的梯度分布;2)从高到低的水分梯度上,灰化苔草群落的物种数先增加后降低,优势种多度逐渐增加,物种多度分布曲线由相对平缓变为陡峭;3)高湿度灰化苔草群落物种多度分布格局的最佳拟合模型为BSM,中、低湿度的理想模型转变为NPM。研究认为,水分条件的变化是灰化苔草群落物种多度分布格局改变的主因,随着水分梯度降低,群落构建的生态学过程由随机生态位变为生态位优先占领。研究为鄱阳湖湿地多样性保育和生态功能管理提供了理论参考。 相似文献
220.
在小麦含水量分别为9.3%、12.6%和14.4%,装满度分别为100%、70%、50%、30%和0%,气体浓度为100mL/m3和400mL/m3的条件下,测定小麦对磷化氢的吸附率,结果表明小麦对磷化氢的吸附率随着粮食水分增加,磷化氢浓度和装满度增大有不同程度增加.在药量较大的施药初期和装满度大时,检测到的磷化氢浓度高于设定浓度,磷化氢浓度、小麦水分和装满度较低时,小麦对磷化氢的吸附较容易达到平衡. 相似文献