基于层次分析法的辽河干流水环境承载力评价研究

目前,水生态文明建设提出后,水环境承载力成为衡量地区可持续发展能力的一项重要指标。为了解辽河干流沿岸城市的水环境承载状况,以辽河干流为研究区域,采用层次分析法,建立以水资源、社会、经济、生态环境为子系统的评价体系。代入各行政分区的样本值,进行辽河干流水环境综合承载能力计算。评价了各行政分区不同现状年的承载状况。     

小型猪近交系新品种的培育与开发利用

小型猪近交系是中国农业科学院北京畜牧兽医研究所以2头五指山猪(Sus scrofa)为系祖,历时15年,采用“近亲交配”、提高营养水平、同期发情以及笼架等饲养技术,逐步克服后代畸形率高、弱仔率高、成活率低等3大阶段性难题,育成国际上首个近交系猪.本文介绍小型猪近交系的培育过程、近交系研究鉴定、新遗传资源种质特性,以及开发利用.该研究成果填补了国内外近交系猪的研究空白,为大型哺乳近交系动物培育理论和应用研究提供了新的视角.     

Cloning and Bioinformatic Analysis of L1 Gene of BPV from Guizhou Province

In order to study and analyze L1 gene of bovine papillomavirus（BPV）in Guizhou province,the L1 gene of BPV-GZ01 strain was amplified,cloned and sequenced using bioinformatic softwares and methods,and the secondary structure,tertiary structure,B-cell preponderant epitope,conserved domains analysis, transmembrane domain and signal peptide of L1 gene were predicted.The results showed that the length of L1 gene was 1 494 bp,encoding 497 amino acids.The L1 gene of BPV-GZ01 strain shared an amino acid identities of 98.6%,99.4%,98.4%,94.4% and 91.3%,and a nucleotide identities of 99.1%,99.8%,99.4%,87.6% and 82.8% with those of BPV2,BPV2-SW01,BPV2-AKS01,BPV13 and BPV1 strains,respectively.The results of phylogenetic tree analysis indicated that there was a close relationship between BPV-GZ01 and BPV2-SW01 strains.The prediction of secondary structure of L1 protein indicated that the random coil,extended strand and alphahelix took a higher percentage.The L1 protein was supposed contain 6 potential antigen epitopes.And no transmembrane domains and no signal peptide were found.The tertiary structure of L1 protein was curved spiral structure.These results provided a theoretical basis for immunologic diagnosis and further research of nucleic acid vaccine of BPV.     

Isolation and Identification of Pathogenic Bacteria Causing Dairy Cow Mastitis in Liaoning and Drug Sensibility Test of Pathogenic E.coli

In order to understand the main bacterial pathogen species causing dairy cow mastitis in Liaoning, as well as the characteristics of drug sensitivity of the pathogenic E.coli,the milk samples from 75 dairy cows with clinical manifestations for mastitis in certain large-scale dairy farm in Liaoning were collected.The bacteria in milk were cultured and isolated with biochemical methods and in vitro drug sensitivity tests were processed with the isolated E.coli strains.The results showed that the main bacterial pathogen for dairy cow mastitis were E.coli（separation rate 58.7%),S.aureus（64.0%）and S.agalactiae（54.7%),and multiple infection including double and triple infection were identified.The drug sensitivity tests on the isolated E.coli indicated that the E.coli isolates were highly resistant to sulfonamides（resistance rate>85%）and chloramphenicol（resistance rate>30%),and they were relatively low resistant to ampicillin（9.5%),ciprofloxacin（9.5%),ceftiofur（7.1%）and ofloxacin（4.8%).The results was able to provide reliable theoretical basis for prevention and control of dairy cow mastitis in Liaoning area.     

东北地区奶牛乳房炎表皮葡萄球菌和腐生葡萄球菌的分子流行病学及耐药性研究

为调查表皮葡萄球菌和腐生葡萄球菌在东北地区的流行病学情况和耐药性,本研究对来自东北地区3个大型奶牛场采集的330份奶样进行葡萄球菌的分离、鉴定及其耐药表型的检测,并采用脉冲场凝胶电泳(PFGE)进行分离株的亲缘性分析,对表皮葡萄球菌进行多位点序列分型(MLST),同时应用PCR扩增分离株中携带的相关耐药基因。研究结果表明,在330份奶样中共分离到表皮葡萄球菌32株(9.7%),腐生葡萄球菌34株(10.3%);PFGE分析共获得9种不同谱型的表皮葡萄球菌和11种不同谱型的腐生葡萄球菌。药敏试验结果显示,两种菌对青霉素(70%)、苯唑西林(60%)和林克霉素(55%)的耐药率较高,主要耐药基因为lnu(B)(40%)、erm(B)(30%)和mec A(25%)。本研究结果揭示了东北地区奶牛乳房炎病原菌表皮葡萄球菌和腐生葡萄球菌的耐药谱和流行情况,为临床合理用药及奶牛乳房炎的防控提供了实验依据。     

放牧管理对西藏高寒沼泽植物群落结构和土壤碳氮的影响

对西藏当雄县3种不同放牧管理模式(冬季放牧、冬春季放牧和全年放牧)下的高寒沼泽的植物群落结构和土壤碳氮进行了调查。调查发现,3种放牧管理模式下的高寒沼泽植物群落总盖度差异不显著,而优势物种藏嵩草的高度和盖度差异显著;放牧管理对沼泽群落结构和物种多样性影响较大,随着放牧强度的增加,物种丰富度增加;放牧利用显著降低了高寒沼泽湿地群落优势物种藏嵩草的高度和盖度,其优势度也显著降低,使得高寒沼泽逐渐退化。冬季放牧、冬春季放牧和全年放牧沼泽地上生物量和地下生物量依次降低。同时,随着放牧强度的增加,高寒沼泽表层土壤有机碳氮的含量也显著降低,且高寒沼泽表层土壤碳氮与地上和地下生物量显著正相关。通过对比分析,冬季放牧是当前西藏高寒沼泽较好的放牧管理模式。     

9种牧草对青海同德牧区土壤特性的影响

通过对青海省高寒牧区常见的9种多年生牧草单播2年后耕层0~15cm土壤理化(pH、容重(BD)、有机碳(SOC)、全氮(TN)、无机碳(C)及微生物学性质(微生物生物量碳(Cmic)、氮(Nmic)和群落代谢功能)等指标的测定分析,结果表明,研究区域只有在种植披碱草2年后土壤有机碳含量有所增加,说明与其他草种相比,种植披碱草利于有机质的积累;试验在每年施肥1次的情况下,土壤氮含量仍然偏低,说明此区氮素被过度利用,处于缺乏水平,因此每年增施氮肥数量、频率以及时间上应加强管理。通过对不同牧草种植区土壤各因子的聚类分析,发现贫花鹅观草、无芒雀麦、紫野麦草和扁穗冰草之间相似度较高,表明其对土壤养分及微生物群落功能的影响较为接近,故在大面积种植的时候可根据牧草地上生物量/质量的高低进行选择性播种。从土壤质量方向考虑,种植杂花苜蓿、红豆草和西北羊茅不利于土地的改良。     

“赤霞珠”葡萄组培快繁体系研究

以"赤霞珠"葡萄为试材,对组培快繁中的取材部位、消毒方法、不同激素用量、是否带叶继代培养等关键技术措施进行了研究探讨。结果表明:以半木质化,0.1%升汞溶液消毒8min的茎段接种,成活率高,污染率低;并且继代培养和生根培养最好的培养基为1/2MS+IBA0.2mg·L~(-1)+蔗糖20g·L~(-1)+琼脂7g·L~(-1)。     

避雨栽培对“户太八号”葡萄生长及果实发育的影响

以"户太八号"葡萄为试材,比较了露地栽培与避雨栽培2种模式下葡萄的生长发育状况、外观品质及理化性质。结果表明:避雨栽培极显著削弱了叶幕层光照强度,为常规栽培的68.71%;避雨栽培下葡萄日平均净光合速率降低12.10%,叶绿素含量平均降低5.57%;在叶幕微气候方面,避雨栽培下叶幕层日平均温度提高了1.68℃,日平均湿度降低了10.98%。与常规栽培比较,避雨栽培平均果粒质量降低了1.52g,平均果穗质量降低了92g;避雨栽培下葡萄的可溶性固形物高于常规栽培,差异不显著;含酸量在果实发育时期极显著低于常规栽培下的葡萄,且差值较大。避雨栽培可显著提高果实固酸比,提高果实品质。     

水分胁迫对幼龄仁用杏叶片光合特性的影响

以2年生仁用杏为试材,采用盆栽方法,以正常供水(土壤含水量为田间最大持水量的75%)为对照,设置了轻度水分胁迫(55%)、中度水分胁迫(45%)和重度水分胁迫(30%)3个处理,开展了水分胁迫条件下仁用杏叶片光合色素、光合指标及叶绿素荧光参数等光合特性研究。结果表明:水分胁迫不同程度降低了类胡萝卜素含量、叶绿素a、b含量、净光合速率(Pn)、蒸腾速率(Tr)、水分利用效率(WUE)、最大荧光产量(Fm)、最大光化学效率(Fv/Fm)和PSⅡ潜在活性,且下降幅度随着胁迫时间延长而增大;轻度水分胁迫下降幅度很小,中度和重度水分胁迫下降幅度较大。