Molecular phylogenetic analysis of Onchocerca lupi and its Wolbachia endosymbiont

The morphology of Onchocerca lupi, responsible for canine ocular onchocercosis, is unique within the genus. Earlier analyses of the 5S ribosomal RNA gene spacer region sequence of the parasite and the 16S ribosomal RNA gene sequence of its Wolbachia endosymbiotic bacteria (Rickettsiales) supported the morphological and biological arguments that O. lupi is a distinct species. However, the exact phylogenetic position of O. lupi and its endosymbiont could not be unambiguously determined. Herein we report analyses based on the mitochondrial cytochrome oxidase I (COI) gene of the filarial species and the Wolbachia surface protein (wsp) and the bacterial cell-cycle ftsZ genes of their wolbachiae. Our results indicate that O. lupi separated from other Onchocerca spp. early in evolution. This is in line with the previous morphological analysis demonstrating that O. lupi is an atypical Onchocerca species showing both primitive and evolved characters. The phylogenetic trees generated for the COI sequences of filariae and the wsp and ftsZ sequences of their wolbachiae were congruent with each other, which supports the hypothesis that nematodes and their Wolbachia endobacteria share a long co-evolutionary history.     

Macroanatomical Aspects of the Lumbar Plexus and its Branches in the Sparrowhawk

This study examined the plexus lumbalis and its branches in the sparrowhawk (Accipiter nisus). Fifteen sparrowhawks were used in this study. After administering an anaesthetic to the birds, the body cavities were opened. The birds were fixed with formaldehyde after draining of the blood. The nerves of the plexus lumbalis were dissected separately and photographed. The plexus lumbalis was formed by the union of the branches of the synsacral spinal nerves, which left from the ventrolaterale of os lumbosacrale. The plexus consisted of three (2nd, 3rd and 4th) synsacral spinal nerves. The cranial and caudal nerves originating from the plexus lumbalis were the nervus cutaneous femoris, nervus coxalis cranialis, nervus femoralis, nervus saphenus and nervus obturatorius. The general macroanatomical shape of the plexus lumbalis and the distribution of the nerves originating from this plexus were similar to those of other bird species.     

不同氮效率紫花苜蓿叶特征及其产量效应研究

为探讨不同氮效率紫花苜蓿(Medicago sativa)叶特征差异及其对产量的影响,本研究采用田间小区试验,设4个不同氮效率紫花苜蓿品种('LW6010'、'甘农3号'、'甘农7号'和'陇东苜蓿')和2个施氮处理(0,103.5 kg·hm-2),对比研究不同氮效率紫花苜蓿的叶特征及其生产性能,并采用通径分析法探讨叶...     

高寒牧区栽培毛苕子多次刈割生产性能研究

对毛苕子不同刈割时间与次数的生产性能进行了对对比,发现其生产能力有很大差别,试验证明,在高寒牧区栽培毛苕子,在整个生育期内刈割２次可获得最高产草量,一茬草与二葜最佳刈割期分别为初花期和结荚初期。     

PEG干旱胁迫对3种葱属植物种子萌发期渗透调节物质及酶活性的影响

为探明东北地区常见野生葱属植物耐旱能力,筛选野生葱属植物耐旱种质资源,本研究以野韭（Allium ramosum L.）、山韭（Allium senescens L.）和蒙古韭（Allium mongolicum Regel）3种葱属植物为材料,采用不同浓度的PEG-6000模拟干旱胁迫,分析其种子萌发期渗透调节物质及酶活性的影响,并结合主成分分析和隶属函数分析比较抗旱性。结果表明：干旱胁迫下,3种葱属植物种子萌发期相对电导率显著升高（P<0.05）,丙二醛、脯氨酸、可溶性糖、可溶性蛋白含量及超氧化物歧化酶、过氧化氢酶、过氧化物酶、多酚氧化酶活性均呈现先上升后下降的趋势。3种植物相比,山韭相对电导率最低,渗透调节物质积累量最高,酶活性变化明显。主成分分析表明,4种酶活性之间显示出强相关性。隶属函数分析得出3种植物种子的抗旱性由高到低依次为：山韭 > 野韭 > 蒙古韭。     

青藏高原东缘中国沙棘的克隆多样性及克隆结构

应用随机扩增多态性DNA标记(RAPD markers)对青藏高原东缘中国沙棘的克隆结构、克隆多样性进行了初步的探讨。结果表明,1) 14条RAPD引物在8个中国沙棘居群共184个样本中平均形成55.75种条带,平均有15.13种条带在居群内表现出多态性,平均多态条带百分率为27.64%;鉴别出26种基因型,平均每基株形成3.4个分株;2)与应用DNA分子标记研究的其他克隆繁殖能力较强的植物相比,中国沙棘的克隆多样性水平偏低,Simpson’s多样性指数(D)平均值为0.85;Fager’s均匀度指数(E)平均值为0.87;3)克隆结构分析表明,中国沙棘每克隆内分株间的平均距离为1.75 m,克隆繁殖的生长型主要为游击型,并且在居群内存在以某一优势基株为主的克隆分布方式;4) 居群的定居时间、生境及群落结构等对中国沙棘的克隆多样性有一定影响。     

Acute viral hepatitis in California sea lions

Acute viral hepatitis was diagnosed in five California sea lions (Zalophus californianus) stranded along the Los Angeles coast. Light microscopy revealed large nuclear inclusion bodies in hepatocytes. Electron microscopy provided evidence that these inclusion bodies were composed of adenovirus-like virions. Attempts to grow the virus in cell culture systems were unsuccessful.     

豫西地区小尾寒羊的饲养方式及农户适度饲养规模的研究

本文采用典型调查法 ,就小尾寒羊在豫西地区的饲养方式及农户适度饲养规模进行了评定。结果表明 ,在海拔 40 0 m以下的丘陵地区或牧坡陡峭的山区宜采用舍饲 ,在丘陵和浅山区宜采用半舍饲的饲养方式。根据对比分析 ,豫西地区农户小尾寒羊的最佳饲养规模为每个劳动力可平均饲养成年母羊 4～ 6只 ,其年末最佳存栏量为 2～ 3只成年母羊     

管理方式对华北驼绒藜生长及种子产量、质量的影响

研究施肥、浇水等不同管理措施对华北驼绒藜生长及种子产量、质量的影响。结果表明,适宜的田间管理可以提高华北驼绒藜的株高、枝条数、种子产量和质量。其中3次施肥+喷钾增产增质效果优于其它处理。3次施肥为最佳施肥方式。浇水及喷施钾肥对促进华北驼绒藜营养生长和提高种子产量、质量没有明显的作用。