拟南芥Alpha-dioxygenase2(AtDOX2)在毕赤酵母中的表达、纯化及活性鉴定

为了获得具有生物活性的拟南芥(Arabidopsis thaliana)alpha-dioxygenase2(AtDOX2),将其对应基因AtDOX2编码区克隆到酵母表达载体pPIC9k中,获得重组表达载体pPIC9k-AtDOX2,将线性化的重组载体电击转化入毕赤酵母(Pichia pastoris)表达菌株GS115,经G418筛选、PCR鉴定和甲醇诱导时间优化,获得重组AtDOX2的高效表达菌株GS115/pPIC9k-AtDOX2。SDS-PAGE分析结果显示,0.5%甲醇诱导96h重组蛋白表达量最高,其表达量占胞外总蛋白的15%。重组AtDOX2的表观分子量约为70kD,经Ni-NTA柱亲和层析可获得纯度大于80%的重组蛋白。2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)法测定结果表明重组蛋白具有过氧化物酶活性,且其活性受Ca2+和Mg2+激活,受EDTA、咪唑和Mn2+抑制;2,4-二硝基苯肼(2,4-DNP)法测定结果显示,重组AtDOX2具有双加氧酶活性,Ca2+对其双加氧酶活性也有激活作用。结果说明利用酵母表达系统获得...     

烟草丛顶病毒(TBTV)ORF3和ORF4的原核表达、抗血清制备及应用

为制备烟草丛顶病毒(TBTV)ORF3和ORF4多克隆抗体,采用RT-PCR方法克隆了TBTV保山龙陵分离物(TBTV-BSLLi)的ORF3和ORF4,亚克隆至pMD18-T载体中,经测序正确后,将该基因插入原核表达载体pET28a(+)中,通过热击转化大肠杆菌(Escherichia coli)BL21(plysS),以IPTG诱导6×His融合蛋白的表达,并经Ni2+亲和柱层析纯化,成功地克隆了TBTV的ORF3和ORF4,建立了其原核表达和表达产物的纯化体系,获得了高纯度的ORF3、ORF4蛋白.用纯化的蛋白免疫大白兔,获得高效价的特异性抗血清.DAS-ELISA检测结果表明,制备的抗血清可用于田间烟草(Nicotiana tabacumL.)样品及传播介体的检测.本研究为用血清学方法检测该病毒提供了基础条件.     

铜壁关自然保护区盈江片区生物多样性评价

对铜壁关自然保护区盈江片区的生物多样性进行评价,结果认为,该保护区是我国纬度最北的热带雨林的一块宝地,生物多样性极为丰富,保护物种也非常丰富,生态保护价值和经济价值较高.目前保护区保护管理机构的层次和能力与保护对象不相协调,急待加强.藉此,对今后的自然保护工作提出了建议.     

对完善长沙市动物卫生体系建设的思考

建设和完善动物卫生体系,提高动物疫病的预防和控制能力,是实现养殖业持续稳定健康发展的前提条件,也是保障食品安全和公共卫生安全的必然要求。本文分析了当前长沙市动物卫生体系的现状和存在的薄弱环节,提出了完善长沙市动物卫生体系的对策与建议。     

大黄酚对黄瓜白粉病的生物活性及内吸传导性研究

采用喷雾法研究了大黄酚对黄瓜白粉病的生物活性及其在黄瓜组织中的内吸传导性。结果表明,大黄酚对黄瓜白粉病菌具有较高毒力,感染白粉病的叶片经200 mg/L的大黄酚处理2 d后,霉状物变褐色,病斑枯死。扫描电子显微镜观察显示,黄瓜白粉病菌经大黄酚处理后,菌丝和分生孢子梗扭曲、变形,分生孢子塌陷。盆栽试验表明,利用大黄酚防治黄瓜白粉病具有较长的持效期,黄瓜子叶上喷施100 mg/L的大黄酚,20 d后接种病原菌,其防效仍达84.83%,与有效成分500 mg/L的硫磺悬浮剂防效相近。此外,大黄酚在黄瓜组织中具有一定的跨层传导性,其横向传导性较弱,几乎无向顶及向基的传导性。     

合成条件对氧气氧化合成水钠锰矿的影响

A pot experiment was conducted to determine the dynamics of soil microbial biomass in a rainfed soil under wheat cultivation at the University of Arid Agriculture, Rawalpindi, Pakistan. The treatments applied were: 1) a control (CK), 2) NPK (0.44-0.26-0.18 g pot^-1), 3) farmyard manure (FYM, 110 g pot^-1), 4)poultry manure (PM, 110 g pot^-1), 5) FYM (110 g pot^-1) NPK (0.44-0.26-0.18 g pot^-1), 6) poultry manure (PM, 110 g pot^-1) NPK (0.44-0.26-0.18 g pot^-1), 7) FYM (110 g pot^-1) NPK(S) (0.44-0.26-0.18 g pot^-1 one half of the NPK at sowing and the other half one month after sowing), and 8) PM (110 g pot^-1) NPK(S) (0.44-0.26-0.18 g pot^-1, one half of the NPK applied at sowing and the other half one month after sowing). The experiment was laid out using a completely randomized design with three replications. Microbial biomass C, N and P contents increased continuously from the beginning of the experiment up to the three-leaf stage. A slight decline was observed at the tillering stage in all treatments except with the organic manures NPK(S) treatments. After tillering there was an increase in all treatments to the recorded maximum point at the full heading stage in all treatments except with the organic manures NPK(S) treatments. In the FYM NPK(S) and PM NPK(S) treatments; however, there was a continuous increase in microbial biomass up to the heading stage. At the harvesting stage a sharp decline was noted in all treatments. The C:N ratio of microbial biomass in tested soil ranged from 7.8 to 11.3, while C:P ratio of microbial biomass in the tested soil ranged from 22.6 to 35.1 throughout all growth stages of the wheat crop.     

菜籽饼肥不同用量对烤烟产量及质量的影响

试验研究了菜籽饼肥不同用量对烤烟产量和质量的影响。结果表明,施25%熟饼肥 75%复合肥的处理烤烟产量、产值最高,在施用饼肥纯N占25%以上时,随着饼肥用量的增加,烤烟产量、产值呈下降态势。饼肥用量相同时,腐熟饼肥产量、产值高于生饼肥。25%熟饼肥 75%复合肥处理的烟叶内在化学品质协调性较好,单施复合肥或单施菜籽饼肥(包括生饼和熟饼肥)都不利于烟叶内在化学品质的协调。     

关于中国农地整理中预测性环境影响评价问题

农地整理作为中国现阶段土地整理的主要形式，对其进行环境影响评价是必要的。在此背景下，该文对农地整理中环境影响评价进行综合分析，指出了农地整理中环境影响评价现状及存在的问题等，并从景观、土壤、生物多样性、水资源、植被、大气等几个方面，对农地整理存在的潜在环境影响进行了分析，在此基础上提出了建立农地整理环境影响评价制度、农地整理环境影响评价的内涵和方法体系，以期对农地整理中环境影响评价有所借鉴。     

Characterization of intergeneric hybrids of <Emphasis Type="Italic">Erianthus rockii</Emphasis> and <Emphasis Type="Italic">Saccharum</Emphasis> using molecular markers

Erianthus rockii, a wild relative of sugarcane, is drought and cold tolerant, and both are potentially important agronomic traits to the sugarcane industry worldwide. As such it is of interest as a source of parental germplasm to sugarcane breeders and is currently being used in sugarcane introgression programs in both China and Australia. To date morphological characters have been used to verify the putative hybrids produced. Two crosses were generated between two different Saccharum species and two E. rockii accessions. Over 400 AFLP markers were used to identify the intergeneric hybrid progeny as well as determine hybrid diversity. Both crosses generated hybrids but efficiency levels were very different and are probably related to the different Saccharum parent used in each cross. Cross 1 was between a Saccharum officinarum and E. rockii and generated 100% hybrid progeny. Cross 2, however, was between a sugarcane hybrid (S. officinarum × Saccharum spontaneum) and E. rockii and only 10% of the progeny were intergeneric hybrids. Inheritance of markers in the progeny was analysed and for both crosses there were equal numbers of markers from both parents indicating n + n transmission of chromosomes. This is the first verification of E. rockii hybrids with molecular markers. It may now be possible to exploit genes of value from E. rockii in sugarcane breeding programs.