2018-2020年中国部分省市猪流行性腹泻病毒S1基因的监测及遗传变异分析

【目的】 调查中国规模化猪场猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)的流行情况。【方法】 利用RT-PCR检测方法对2018-2020年采集于全国11个省市318个规模化猪场的2 391份样品进行PEDV核酸检测,对30份阳性样品进行S1全基因扩增与测序,并利用MegAlign、Mega 7.0等软件进行分析。【结果】 2018-2020年,猪场PEDV核酸阳性率分别为48.57%、10.96%和4.72%,样品PEDV核酸阳性率分别为28.97%、8.27%和7.50%,猪场和样品PEDV核酸阳性率呈现逐年下降的趋势。S1基因相似性分析显示,获得的30株毒株全部为GⅡ基因型,其中17株毒株为GⅡa基因亚型、5株毒株为GⅡb亚型、8株毒株为GⅡc亚型,GⅡa基因亚型毒株为2018-2020年流行的主要毒株类型;30株毒株S1基因序列之间核苷酸相似性为93.0%~99.5%, 氨基酸相似性为91.7%~100%,其中22株毒株与2017-2018年流行的GⅡ基因型毒株相比S1氨基酸序列表现出特征性插入和缺失。【结论】 本研究结果为监测和分析中国PEDV的变异和演化提供了临床数据,为猪流行性腹泻防控和疫苗研制提供了参考。     

Isolation,Identification, 16S rRNA Gene Sequencing and Genetic Evolution Analysis of Aeromonas aeruginosa from Duck

【Objective】 The experiment was aimed to study the pathogenic bacteria of acute death of ducklings in a duck farm in Henan province and its phylogenetic status.【Method】 The liver and spleen of dead ducks in the diseased duck farm were collected.The bacterial morphology, Gram-staining, biochemical characteristics, sequence analysis of 16S rRNA gene, drug sensitivity test and pathogenicity test were carried out.【Results】 The isolated bacteria grew on blood agar medium with smooth, convex, milky white and α-hemolytic Gram-positive cocci.Biochemical test results showed that the isolated bacteria were positive for maltose, sucrose, raffinose, nitrate reduction reaction, MP-VP test, urea, lysine decarboxylase, ornithine decarboxylase and aescin, and negative for xylose, lactose, glucose, sorbitol, hydrogen sulfide, citrate, peptone, mannitol, phenylalanine and methyl red.The results of 16S rRNA gene sequencing and BLAST comparison results showed that the 16S rRNA gene sequence of the isolated strain was 94.8%-99.9% similar to that of Aerococcus viridans published on NCBI, and the similarity with strains Mnlv1, Mnlv2 and W66 was the highest, up to 99.9%.The similarity with strain GXBl-1 was the lowest, which was 94.8%.Phylogenetic tree analysis showed that the isolated bacteria belonged to the same genus and group on the same branch as strains of Aerococcus viridans FL09, 15MS and Mnlv2 etc., and had the closest genetic relationship with FL09.The results of drug sensitivity showed that the isolated strain was sensitive to fosfomycin, ampicillin and amoxicillin, moderately sensitive to penicillin, neomycin and amikacin, it was resistant to rifampicin, neomycin, bacitracin, erythromycin and enrofloxacin.The results of pathogenicity test showed that the strain was lethal and increased with the increase of inoculation concentration.【Conclusion】 This study determined that the pathogen causing the acute death of ducklings in a duck farm in Henan province was Aerococcus viridans, which provided a reference basis for clinical diagnosis and treatment of the diseases caused by this bacteria.     

猪多杀性巴氏杆菌的分离鉴定及oppA基因遗传进化分析

【目的】了解福建省猪场猪多杀性巴氏杆菌（Pasteurella multocida,Pm）的流行及oppA基因遗传进化情况。【方法】本研究采用细菌分离培养、生化试验、16S rRNA PCR扩增测序、PCR荚膜分型、oppA基因克隆及相似性分析、动物回归试验等方法对分离菌株进行鉴定和分析。【结果】本研究共分离到10株菌,分离菌在血平板上形成淡灰白色、湿润光滑、奶油露珠状菌落;分离菌株能酵解蔗糖、果糖、麦芽糖和甘露醇,不能分解葡萄糖、枸橼酸盐、乳糖、硫化氢等,与多杀性巴氏杆菌生化特性基本一致;分离菌株16S rRNA序列与GenBank中登录的多杀性巴氏杆菌相似性达99.9%以上,10株分离菌均为多杀性巴氏杆菌;PCR荚膜分型显示,6株分离菌为荚膜A型,4株为荚膜D型;基于oppA基因的遗传进化树显示,10株分离菌均位于同一分支内;动物回归试验结果显示,在24 h内攻毒小鼠死亡率较高（21/30）,分离菌有较强的致病力。【结论】福建省猪场猪多杀性巴氏杆菌流行菌株的荚膜血清型主要是A和D型,且大部分菌株都来源于共同的祖先,本研究结果丰富了猪多杀性巴氏杆菌的流行病学资料,并为该病的防控奠定基础。     

Investigation of Co-infection of PPV7 and PCV2 and Genetic Variation Analysis for PPV7 Cap Gene in Fujian and Guangdong

【Objective】 To investigate the co-infection situation of Porcine parvovirus (PPV7) and Porcine circovirus type 2 (PCV2)in Fujian and Guangdong, and to understand the molecular genetic characteristics of PPV7 Cap gene.【Method】 The blood sample of 432 infected pigs from 69 pig farms in Fujian and Guangdong were collected to detect PPV7 and PCV2 by PCR.The PPV7 Cap gene of positive samples was cloned and sequenced.The DNAStar software was used to analyze the nucleotide and amino acid sequences of PPV7 Cap gene, and Mega 7.0 software was used to draw the genetic evolution tree.【Result】 The results showed that the positive rate of PPV7 was 21.99% (96/432), the positive rate of farms was 53.62%(37/69), and the positive rate of PCV2 was 54.17% (234/432), and the co-infection rate of PCV2 and PPV7 was 13.43% (58/432).The 17 PPV7 Cap gene sequences were amplified using PCR.Nucleotide homology analysis revealed that the homology of the 17 PPV7 Cap gene sequences was 85.6%-100%, and the homology with reference strains was 85.8%-99.0%.Amino acid sequence comparison analysis revealed that the amino acid homology of the 17 PPV7 Cap protein sequences was 87.6%-100%, and the amino acid homology with reference strains was 82.6%-98.7%.Phylogenetic analysis of Cap gene showed that PPV7 could be divided into five main evolutionary branches of PPV7a-PPV7e, among which 9 isolates belonged to PPV7a subtype, 3 isolates belonged to PPV7b subtype, 4 isolates belong to PPV7c subtype, and only 1 isolates isolates belonged to PPV7e subtype.【Conclusion】 This study indicated that PPV7 was widely prevalent in Fujian and Guangdong regions, and had a high co-infection rate with PCV2, which might be the pathogenic factor of Porcine circovirus associated disease(PCVAD).The genetic diversity of PPV7 isolates was abudant in both regions, and PPV7a was the dominant strain at present.The findings of this study provided theoretical basis and data reference for PPV7 prevention and control and vaccine research.     

俄罗斯联邦的森林资源及其特性

俄罗斯联邦森林资源极为丰富,在世界上占有重要地位,其森林资源本身具有地域分布的不均匀性、变动的相对稳定性、针叶树种及成过熟林蓄积的优势性十分明显。这些特点为中俄林业合作开发亚洲地区的森林资源奠定了良好的物质基础。     

武当山地区野生有毒植物资源的开发利用研究

经调查,湖北武当山地区共有野生有毒维管植物71科156属206种。本文分析和讨论了它们的经济价值、在本地区的开发利用现状及存在的问题,提出了保护与开发对策。     

云南红河州膏桐的资源分布及生长结实状况调查

为发展膏桐种植业,对云南省红河州膏桐产地的资源分布及开花结实状况进行了调查,掌握了该地区膏桐的资源量及分布特性;并从树高、地径生长、不同树冠面积以及植株的开花结实方面了解了该地区膏桐的生长及开花结果的状况。     

Research Advancement in Genetic Variation of Wood Properties

The genetic improvement of wood properties is one of the important measures of improving wood quality. To achieve that, forestry and wood scientists have done a great deal of research in expectation to produce more high-quality wood. The paper summarizes the researches on genetic variation and genetic correlation of wood properties and proposes the prospects to conduct the genetic improvement of wood properties.     

人工林改性木材研究及应用前景

概述了近10年来国内外学者在人工林木材改性方面取得的研究成果，并提出了改性木材目前存在的问题以及未来发展趋势，从资源的可行性和市场前景对人工林改性木材的应用进行深入探讨。     

滇杨遗传改良策略初论

滇杨是我国西南地区特有的一种乡土树种，也是我国乃至世界少有的分布于低纬度高海拔地区的杨属树种。针对目前国内滇杨遗传改良研究几为空白的现状，对其遗传改良的途径进行了系统探讨。从滇杨的资源特点及研究现状出发，在借鉴国内外杨树遗传改良成功经验的基础上，提出常规育种与现代生物技术育种有机结合，形成一个系统高效、合理可行的滇杨遗传改良策略。