Molecular taxonomic relationships of Psoroptes and Chorioptes mites from China based on COI and 18S rDNA gene sequences

In this present study, the mitochondrial DNA gene cytochrome coxidase subunit I (COI) and the small subunit ribosomal RNA (18S rDNA) gene were used to determine the taxonomic relationships of Psoroptes and Chorioptes mites from China. The neighbor-joining and maximum-parasimony approach were used to evaluate the evolutionary relatedness among different hosts in the genera Psoroptes and Chorioptes. Phylogenetic analysis showed that Psoroptes cuniculi and Psoroptes natalensis may be two different species within the genus Psoroptes, and Chorioptes texanus and Chorioptes panda are different species within the genus Chorioptes.     

杂交苜蓿(Medicago varia Martyn)根系特性的研究

杂交苜蓿是野苜蓿 (M .falcata)和紫苜蓿 (M .sativaL .)的杂交后代 ,兼具亲本的许多优良性状 ,适于广泛栽培。对其在根系特性上所表现出的优势进行研究发现 :根颈处的劈裂将植株分为母株与子株 ,实现营养繁殖 ;位于茎基部的当年芽数量明显大于亲本 ,是地上生物量增长的基础 ;明显的缩根现象有利于茎基部和根颈顶部芽的产生和越冬 ;明显优于亲本的侧根与不定根 ,为根劈裂分株繁殖的植株提高地上生物量奠定了基础     

改革创新开拓蚕业现代化新局面

“十五”期间蚕业将面临从计划经济走向经济的重大改革。蚕茧流通体制改革、企业制度改革、事业单位改革都会给蚕业生产带来巨大冲击。蚕业必须深改革,加快体制创新和技术创新,从调整结构,形成专业化分工的区域区布局,探索桑地流转机制,扩大生产规模,加强生产基础,加快实用技术创新,实行产业化经营等方面入手,开拓蚕业现代化的新局面。     

Pyruvate kinase is necessary for Brucella abortus full virulence in BALB/c mouse

Brucellosis, caused by a facultative intracellular pathogen Brucella, is one of the most prevalent zoonosis worldwide. Host infection relies on several uncanonical virulence factors. A recent research hotpot is the links between carbon metabolism and bacterial virulence. In this study, we found that a carbon metabolism-related pyruvate kinase (Pyk) encoded by pyk gene (locus tag BAB_RS24320) was associated with Brucella virulence. Determination of bacterial growth curves and resistance to environmental stress factors showed that Pyk plays an important role in B. abortus growth, especially under the conditions of nutrition deprivation, and resistance to oxidative stress. Additionally, cell infection assay showed that Pyk is necessary for B. abortus survival and evading fusion with lysosomes within RAW264.7 cells. Moreover, animal experiments exhibited that the Pyk deletion significantly reduced B. abortus virulence in a mouse infection model. Our results elucidated the role of the Pyk in B. abortus virulence and provided information for further investigation of Brucella virulence associated carbon metabolism.     

Development of a disperse dye immunochromatographic test for the detection of antibodies against infectious bursal disease virus

For investigating the feasibility of using disperse dyes as an immunoassay chromogenic marker, a disperse dye, DADISPERSE NAVY BLUE SP, was selected in analyzing antibody against infectious bursal disease virus (anti-IBDV). With the color intensity revealed in the disperse dye immunochromatographic test (DICT) strip as the objective function, the optimal dyeing conditions were found as follows: dye concentration absorbance (at lambda(max)=587nm)=3, pH 7, 50 degrees C, for 10min. Under these conditions, the resultant dyed-antibody (rabbit anti-chicken) can produce an optimal color intensity reading of 55,054 on the strip. For performing qualitative immunoassay, chicken sera samples taken from different farms were used for the anti-IBDV titre assessment. The results of DICT strips showed very high sensitivity and specificity as compared to that analyzed by FlockChek enzyme linked immunosorbent assay (F-ELISA) kits. For quantitative immunoassay, it was found that the color intensity measured with DICT was linearly correlated to that of F-ELISA titre (r(2)=0.9687). Therefore, DICT was further applied to the detection of chicken anti-IBDV sera under vaccination in the farms. The average titres of the sampling groups exhibited a strong agreement to that of F-ELISA. Accordingly, the DICT method developed in this study, shown to be reliable, cheap and simple in both qualitative and quantitative immunoassays, is particularly suitable for point-of-need testing (PONT) in agricultural applications.     

青蒿素及其衍生物的作用机理及其对鸡球虫病的防治

对青蒿素及其衍生物的作用机理及近年来其在防治鸡球虫病的应用做了较详细的综述,以期为其在防治鸡球虫病中的应用提供参考。青蒿素被用于治疗疟疾已有几百年的历史,它还具有治疗血吸虫、腹泻及清热、镇静安神的作用,但其在兽医临床中的应用还是一个新领域。     

山东省沂南县动物强制免疫“先打后补”现状分析

2021年,沂南县推进动物疫病强制免疫“先打后补”工作,依托“鲁牧云”信息平台,通过强化组织领导,加强政策宣贯,强化人员培训,放开强免疫苗经营渠道,提供抗体检测无偿服务等措施,提升了养殖场户“先打后补”的积极性、自主性、灵活性,强化了养殖场户动物防疫主体责任,满足了养殖场户疫苗多样化需求。但由于 “先打后补”补助金额少、社会化服务不规范、基层动物防疫体系弱化、缺少配套工作经费等原因,部分养殖场户实施“先打后补”的积极性不高。建议通过规范社会化服务组织,强化培训水平,提高补助标准,强化三级（县乡村）基础设施建设,升级“鲁牧云”等措施,确保“先打后补”政策惠及更多养殖场户。     

陇西南塬区农业生产系统结构与效益研究

本研究通过对陇西南塬区农业生产系统的结构分析，确认该系统的特征为产业结构不合理（以种植业为主），种植业以粮食生产为主，复种指数低（１１１％）；养殖业中草食家畜比例低，饲养技术落后，良种率低；林果业效益低下；人口密度高，劳动力过剩，生产能源短缺等。通过系统分析提出了调控方针，该系统整体效益提高的关键是发展以草食家畜为核心的养殖业，种植业应及时调整结构，提高经济作物和饲料作物的比例，提高复种指数，林果     

鱼类神经坏死病毒纳米探针的制备与特征分析

为了快速检测鱼类神经坏死病毒,本研究设计了病毒特异性的发夹型探针,经硫醇修饰后与纳米银溶胶结合,制备了鱼类神经坏死病毒纳米探针（Ag-NNV）,并使用透射电镜、多功能酶标仪、表面增强拉曼光谱仪等对纳米探针Ag-NNV的表征及发夹型探针在纳米银粒子表面的覆盖率进行了测定和分析。结果表明,裸露的纳米银粒子为球形,平均直径50 nm;制备的纳米探针颗粒为球形,平均直径90 nm。纳米银粒子和纳米探针在溶液中均具有良好的分散性。平均每个纳米银粒子表面结合发夹型探针约100条,单位表面积的探针覆盖量为0.56 pmol/cm2。该纳米探针制备简便,适合用于表面增强拉曼散射法对鱼类神经坏死病毒进行快速检测。