沙门氏菌invH基因的序列分析与分子检测

根据沙门氏菌的invH基因序列设计1对引物,应用聚合酶链反应技术,分别对3种沙门氏菌标准菌株和5种非沙门氏菌株进行PCR扩增,结果3种标准沙门氏菌株均扩增出479 bp的特异条带,非沙门氏菌皆无特异带扩增。对3种标准株的扩增片段进行克隆及序列分析,证实沙门氏菌的invH基因序列比较保守;对19种地方分离沙门氏菌进行PCR特异性检测,结果有16株扩出特异性条带,表明本研究建立的沙门氏菌检测方法具有较高的特异性。     

海州湾生态修复效果评价

为评价海州湾生态修复工程实施的效果,在分析2014年春、夏、秋3个季节本底调查数据的基础上,以"资源—环境"作为准则层,共筛选16项具体的评价因子建立生态修复效果评价指标体系,并用德尔菲法和熵权法组合赋权,通过效用函数估算海州湾生态修复治理目标的实现程度。结果表明:通过投放人工鱼礁,海州湾生态修复率达到30.14%,其中,生物资源平均修复率为17.96%,海洋环境平均修复率为33.15%,生态修复治理目标综合值为0.400 2,综合修复等级为中等。研究表明,海州湾生态修复工程对水质环境的改善效果较为明显,但对生物资源的恢复效果还有待进一步提高。     

河池市农业资源及粮食综合生产能力评价

进入21世纪,人口与耕地、粮食的矛盾是农业资源优化配置的最大障碍,加强粮食综合生产能力建设,确保粮食安全已成为经济社会发展的重大战略目标。笔者通过综合分析评价河池市现实的农业资源和影响粮食生产能力的要素,进行了潜在的粮食综合生产能力分析。同时提出保护和提高河池市粮食综合生产能力,除国家在政策和财政上继续支持粮食生产外,应优化粮食生产的区域布局,保护好基本资源,优化耕地利用结构;要加强农田基本建设,大力改造中低产田;要实行科技兴农,推广应用粮食生产新技术,以实现农业可持续发展,促进农民增收,确保粮食安全。     

禽肉中总汞测定的不确定度评定

[目的]更科学合理地表示原子荧光法测定禽肉中总汞含量的测量结果.[方法]按照国标方法对禽肉中的总汞含量进行了测量,分析了测量过程中的不确定度来源,并对各个分量进行了评定.[结果]分析表明,试样称量、消化液定容及标准溶液引入的不确定度很小,标准系列配置、线性回归、仪器检测性能及回收率引入的不确定度较大.[结论]研究可为今后禽肉中总汞含量的准确测定提供参考依据.     

一种改良的提取草莓属叶片总RNA的方法

探索一种新的适合草莓属（Fragaria spp．）组培苗、大田苗叶片总RNA的快速高效提取方法。试验以草莓叶片为材料,用改进的CTAB法对其RNA进行提取,并对提取的RNA进行了电泳检测、含量测定和RT-PCR检测。结果表明：用该RNA提取方法提取的RNA具有28S rRNA、18S rRNA和5.8S rRNA3条清晰的条带,且无降解。OD260/OD280在1.83至2.14之间,具有较高的纯度,且含量较高。用该RNA提取方法提取的RNA逆转录成cDNA,经PCR扩增出现清晰的条带,说明该RNA提取方法提取的RNA可以满足进一步分子生物学试验的要求。     

基于APT和模糊数学的黑龙江省绿色食品全过程质量评价体系研究

黑龙江省绿色食品产业是黑龙江经济发展的重要部分,因此建立黑龙江省绿色食品全过程的质量评价体系,能为黑龙江省的经济发展带来巨大动力。从绿色食品的产地环境、种植条件及绿色食品的加工、包装和运输等环节对其质量评价进行研究。首先建立了黑龙江省绿色食品质量评价指标体系,然后应用层次分析法（AHP）测定影响因素的权重,并采用模糊综合评判法对黑龙江省绿色食品质量进行评价,最后以黑龙江省庆安县绿色食品生产为例,应用所建立的模糊综合评价模型进行评价,其综合评价所属等级是良好。     

分光光度计测定水发产品中甲醛含量的不确定度评定

用分光光度计测定水发产品(水发海参)中甲醛含量,分析和评估了影响测定结果的各种因素,建立测量不确定度数学模型,对各不确定度进行量化处理,认为影响水发产品中甲醛含量测定结果的主要因素是试验重复性操作的过程、标准工作液及蒸馏液浓度的精确度。     

半微量凯氏法测定植株中全氮及测量不确定度评定

[目的]测定植株中全氮并对测量不确定度进行评定。[方法]以浓H_2SO_4和H_2O_2为消煮液,采用优化后的升温程序,用半微量凯氏法测定植株中全氮。[结果]通过对植株样品和标准植株样的测定及不确定度评定可知,测定数据可靠,结果准确合理。[结论]测定过程中的不确定度主要来源于盐酸标准溶液和试样测定重复性,为实验室准确快速测定植株中全氮提供参考。     

鲜食糯玉米新组合及其食味品质评价研究

在鲜食糯玉米鲜果穗采收期,从鲜果穗产量、商品性和食味品质3个方面对39个鲜食糯玉米新组合进行综合评价,探讨了鲜食糯玉米新品种选育中新组合筛选及其食味品质的评价方法。     

苏州地区大花萱草新品种的筛选与评价

[目的]对引进的207个大花萱草(Hemerocallis spp.)品种进行筛选与评价,确定适合苏州地区栽培的大花萱草品种。[方法]通过对大花萱草栽培形态特征进行连续观察,将所有引进品种进行逐一筛选;根据测量性状进行分类,对其花色、抗性、植株高度和花期长短等性状进行考评。[结果]筛选出适合苏州地区生长的优良品种16个,其中常绿品种5个(sf-2、sf-3、sf-4、sf-6、p-14)、大花品种6个(n-2、n-3、n-4、n-5、p-24、nz-51)、2次开花品种1个(g-6)、长花期品种1个(j-1)、矮化品种1个(nzy-1)、复瓣品种2个(nzy-2、sf-11)。[结论]筛选出的16个优良大花萱草品种,适合长三角地区大范围推广,为园林设计提供更多的材料。     

表面活性剂辅助提取沙棘叶黄酮工艺优化及其抗氧化活性测定

通过单因素试验优化表面活性剂辅助提取沙棘(Hippophae rhamnoides L.)叶中黄酮的提取工艺,并且对粗提液的抗氧化活性进行测定。结果表明,表面活性剂辅助提取沙棘叶黄酮的最佳提取工艺为选用0.02 g/m L的蔗糖酯作表面活性剂、乙醇体积分数5%、提取温度70℃、料液比1∶70(g∶m L)、提取时间1.5 h,此条件下黄酮提取率为1.6%。黄酮粗提液对超氧阴离子自由基、羟自由基、DPPH自由基有明显的清除作用。     

消费者对食品安全评价及其影响因素分析———基于北京市朝阳区生鲜食品安全调研数据

随着近几年食品安全事故的频发,食品企业和经营商的信用遭到严重冲击,政府和相关监管部门的权威性面对前所未有的挑战。消费者是食品安全流通过程中的终端目标,消费者在食品安全上所体现的态度和消费倾向会对食品生产者、加工及经销企业的行为主体产生深刻影响。采用最优尺度回归方法,对影响北京市朝阳区消费者对食品安全评价的主要因素进行回归分析,如消费者的个人特征、是否常去街边摊贩采购、对新鲜程度和销售环境的满意度,以及对下架食品信息关注度等,并提出相关建议。     

湖南地区蔬菜中总锑含量分析及污染评价

[目的]了解湖南地区的新鲜蔬菜中总锑含量状况,评价蔬菜中锑污染程度,为重金属锑的污染防治工作提供基础数据。[方法]利用氢化物发生-原子荧光光谱法(HG-AFS)测定蔬菜中总锑含量,并采用重金属单因子污染指数法对不同种类蔬菜中总锑含量状况进行评价。[结果]703份蔬菜样品中,总锑含量总体算术平均值为0.090 mg/kg,中位数为0.018 mg/kg,最小值为未检出,最大值为3.120 mg/kg。其中叶类蔬菜中总锑含量高于根类、茎类、花类、果类蔬菜(P0.05),经重金属单因子污染指数法评价,所有蔬菜中重金属单因子污染指数均小于0.2。[结论]湖南地区所采集的蔬菜样品均检出锑,但总锑含量处于正常水平,尚未出现锑污染现象。     

河南省栽培平菇品种的种质资源评价

通过拮抗试验,将供试的61个菌株划分为13个营养亲和群,酯酶同工酶电泳显示同一营养亲和群的菌株其同工酶带型一致.而从13个营养亲和群中分别选出1个菌株,酯酶同工酶分析,具有丰富的多态性;ISSR扩增共获得106个位点,多态性位点比例(P)为95.4％;对13个菌株进行ITS扩增,扩增片段测序比对结果表明,13个菌株中1...     

Antagonistic Activities of Volatiles from Four Strains of Bacillus spp. and Paenibacillus spp. Against Soil-Borne Plant Pathogens

The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathogenic fungi with wide host plants, induced the mycelial morphological abnormalities, and decreased the sclerotoid production of Sclerotinia sclerotiorum in sealed plates. Spores of Botrytis cinerea exposed to these volatiles for 24-48 h in cavity slides cracked and the sporaceous inclusion became brown and effused to the suspension. An interesting phenomenon observed was that all the bacterial volatiles exhibited intense inhibitory activities against the pigment formation of tested pathogenic fungi, including Ascochyta citrullina, Alternaria solani, Alternaria brassicae, and so on. Interactions mediated by microbial volatiles could be widespread in soils, and volatiles may play an important role in reducing disease levels. A phylogenetic analysis based on 16S rDNA sequence placed the four bacteria in three species Paenibacillus polymyxa （BMP-11）, Bacillus subtilis （BL02）, and Bacillus pumilus （BSH-4 and ZB 13）. Through headspace sampling and GC-MS analysis, a rich profile was found from B. subtilis and overlapping volatile patterns could be found among the different species. Studies are under the way to find the possible action mechanisms and to seek the effective application of bacterial volatiles in greenhouse.     

黄石市郊蔬菜基地重金属含量及评价

对湖北省黄石市郊区蔬菜生产基地5种有害重金属Hg、As、Pb、Cd、Cr进行了检测，以国家规定的无公害蔬菜产地环境标准评价重金属污染状况，结果表明，团城山区、西塞山区和江北农场蔬菜基地的重金属综合污染指数均低于0．7，污染程度均为安全，污染水平为清洁；下陆区蔬菜基地重金属综合污染指数为1．0，污染程度为警戒线，污染水平为尚清洁。     

阿拉尔片区部分豆制品卫生学评价

本实验是以阿拉尔片区部分豆制品卫生质量进行感观和细菌学评价,为消费者的健康饮食做以指导。结果显示:阿拉尔片区所售的部分豆制品存在着卫生质量问题,菌落总数不合格的为44%;大肠菌群数不合格的为25%;九团检样豆腐中检出一例蜡样芽胞杆菌,阿拉尔片区部分豆制品总体合格率占检样的56%。     

Analysis of SSRs Information in Capsicum spp.from EST Database

SSR markers are useful in pepper linkage mapping and gene location.446 SSR markers have been reported,but they are insufficient.It is costly to develop SSR markers from DNA library,whereas it seems much easy to find in EST sequences in the GenBank of pepper through internet.In this study,attempts have been made to develop SSR markers in the EST sequences by using bioinformatics.EST sequences were trimmed by ‘est-trimmer.pl' software,while 116 915 EST sequences were obtained without poly ‘A' or poly ‘T',ranged between 100 and 700 bp.Using ‘e-PCR' and ‘del.pl' softwares,SSR sequences were identified.2 508 microsatellite loci (larger than 20 repeats) were established and 755 SSR primers were designed using SSR finder software and Primer 3 software.There were 498 (0.43％) mono-,1 026 (0.89％) di-,5 1 8 (0.45％) tri-,245 (0.21％) tetra-,114 (0.10％) penta-,and 107 (0.09％) hexa-nucleotide SSRs.The estimated frequency of SSRs was approximately 1/25.12 kb.According to the distribution of SSRs in pepper,the mean length of pepper SSRs was 22.68 bp and the adenine rich repeats such as A/T,AG,AT,AAG,AAAT,and AAAC were predominant in each type of SSRs (mono-,di-,tri-,tetra-,penta-,and hexa-),whereas the C/G,CG,CCG repeats were less abundant.210 primers were tested in 8 pepper cultivars and the PCR result revealed the existence of polymorphism among 127 (60.48％) SSR primers within 8 pepper cultivars.It is confirmed that pepper EST database could be efficiently exploited for availability of SSR markers.     

Molecular Identification and Characterization of Cryptosporidium spp. from Mainland China

Three isolates of the genus Cryptosporidium, namely, Guangdong isolate, Anhui isolate and Jiangsu isolate from Mainland China, were identified and characterized genetically utilizing nuclear DNA regions of the small subunit of ribosomal RNA (SSU rRNA) and heat shock protein 70 gene (HSP70) as genetic markers. These two regions were amplified by PCR from DNA extracted from oocysts and amplicons of approximately 290 bp and 450 bp were produced, respectively. The amplicons were purified, cloned and sequenced. Sequences of 446 bp and 290-292 bp were obtained for the SSU rRNA and HSP70 regions, respectively. The obtained SSU rRNA and HSP70 sequences representing the three Cryptosporidium isolates were compared with those retrieved from the DNA database. Genetic analyses using either DNA region revealed that members of Cryptosporidium formed two clusters, with C. parvum, C. wariri, C. felis and C. meleagridis clustered together, while C. andersoni, C. muris and C. serpentis belong to the other cluster. Based on SSU rRNA and HSP70 sequences, both Guangdong and Anhui isolates of Cryptosporidium were identified as C. muris of the calf genotype (i.e., C. andersoni), whereas the Jiangsu isolate was identified as C. parvum of the calf genotype. The findings of the present study should have important implications for the diagnosis and control of Cryptosporidium infections in both humans and animals in China.