杭州地区黄瓜猝倒病菌产嗜铁素拮抗菌的筛选与评价     

梁建根  吴吉安  竺利红  李孝辉  桑金隆  姚杭丽  施跃峰 《勤云标准版测试》2006,(11)

从杭州地区各蔬菜种植地大量采集土样,采用平板稀释法从中分离纯化得到789个细菌分离物。室内平板对峙法获得对黄瓜猝倒病菌有明显拮抗作用的菌株21个,所占比例为2.67%,其抑菌圈直径为3.1￣16.4mm。再利用选择性培养基法从中筛选得到9株嗜铁素产生菌。最后对黄瓜猝倒病菌产嗜铁素拮抗菌进行评价,结果表明,各菌株产生嗜铁素的能力不同,定性与定量分析结果基本吻合;嗜铁素光吸收特性研究表明,pH直接影响嗜铁素光吸收,过酸过碱的条件光吸收峰偏向短波长,而中性条件下光吸收峰偏向长波长。pH8.3有3个吸收峰,分别在224.0nm,264.0nm和400.0nm附近,并且光吸收峰最大,说明pH8.3较适合试验菌产嗜铁素;嗜铁素产生菌对黄瓜生长的初步研究表明,其对黄瓜生长有3种作用即:促进、抑制和影响不大。  相似文献   

油葵（向日葵）栽培管理技术要点     

禹代林  边巴  桑布 《西藏农业科技》2007,29(1):37-39

本文简述了油葵的经济价值与用途,提出了油葵栽培管理技术要点。  相似文献   

农业产业化发展中存在的问题与对策   总被引：1，自引：0，他引：1  

桑卫民 《山东省农业管理干部学院学报》2001,17(4):27

农业产业化 ,是以国内外市场为导向 ,以提高经济效益为中心 ,按照市场牵龙头、龙头带基地、基地连农户的形式 ,优化组合各种生产要素 ;对农业或农村经济的主导产业或重点产品 ,实行区域化布局、专业化生产、系列化加工、一体化经营、社会化服务、企业化管理 ,逐步形成种养加、产供销、贸工农、经科教一体化的生产经营体系 ,使农业走上自我发展、自我调节的良性发展轨道 ,推进农业现代化进程。通过实践 ,我们发现农业产业化发展中存在的主要问题有 :第一 ,各地发展不平衡 ,总体水平不高。第二 ,区域间产业结构趋同现象较为严重。第三 ,运行机…  相似文献   

生物钾肥不同施用方法对冬小麦生长发育及产量效应的分析   总被引：1，自引：0，他引：1  

桑俊民  王赐芳 《河北农业大学学报》1996,19(2):116-119

本文根据硅酸盐菌剂即生物钾肥具有分解和氧化土壤硅酸盐矿物，破坏矿物晶体构造，转化土壤中无效钾的机能，于１９９２～１９９４年进行了生物钾肥对冬小麦生长发育与产量效应的试验研究。探讨出以播前拌种返青沟施是促使小麦促根、增蘖、抗寒、抗干热风、增穗、增粒、增重，提高缺钾麦田再创高产的重要途径。  相似文献   

内蒙古河套灌区碱荒地物理性质及治理效果的研究     

桑以琳  冯素珍  郭玲  贺斌 《内蒙古农业大学学报(自然科学版)》1997,(3)

本文简述了内蒙古河套灌区自然概况，盐碱化演变过程和碱荒地的改良现状。着重说明了碱荒地物理性质和经过治理后的改善情况。  相似文献   

生殖激素诱导母牛双胎效果及机理研究     

桑润滋  李建国  王凤鸣  张正姗  郑德富  贾洪生  高锐  宋宝满 《河北农业大学学报》1997,(4)

用生殖激素（PMSG和纯化的FSH）诱导母牛双胎进行了试验研究。PMSG处理组：选产后50d以上12头参试母牛，按其发情顺序随机分成3个组，每组4头牛，3组牛在发情周期的第10d分别各肌注PMSG2000IU，1650IU，1350IU，间隔48h再肌注氯前列烯醇2支（4mL），发情后按常规进行人工授精，同时再肌注与PMSG等量的抗PMSG，间隔12h再输精1次。上述3组牛每组随机选2头牛在输第一次精的同时肌注LRH－A_3200μg，以比较其对双胎率有无影响。纯化FSH处理组：选产后50d以上的6头参试母牛按发情顺序随机分成2组，一组FSH总剂量为6mg，另一组为5mg。其处理方法是在发情周期的第10，11，123d每天早、晚各1次给参试牛肌注FSH，在第一次肌注FSH48h后肌注氯前列烯醇2支（4mL），发情后正常输精，间隔12h再输精1次。上述6头参试牛中随机选3头牛于输第1次精的同时肌注LRH－A_3200μg。每头参试牛于不同生理时期，包括肌注生殖激素的当天，24h，48h；肌注氯前列烯醇后24h，48h；发情后48h，排卵时，妊娠后第5d，20d，60d。从颈静脉各采血1次，共采10次，每次10mL，离心后分离血清，用放免法测定上述各生理时期血清中P_4，LH，E_2水平，分析与单、双胎的关系。结果表明（1）适量的PMSG（1350～2000IU）和纯化FSH（5mg）均能诱导母牛  相似文献   

Mutations in U4atac snRNA, a component of the minor spliceosome, in the developmental disorder MOPD I     

He H  Liyanarachchi S  Akagi K  Nagy R  Li J  Dietrich RC  Li W  Sebastian N  Wen B  Xin B  Singh J  Yan P  Alder H  Haan E  Wieczorek D  Albrecht B  Puffenberger E  Wang H  Westman JA  Padgett RA  Symer DE  de la Chapelle A 《Science (New York, N.Y.)》2011,332(6026):238-240

Small nuclear RNAs (snRNAs) are essential factors in messenger RNA splicing. By means of homozygosity mapping and deep sequencing, we show that a gene encoding U4atac snRNA, a component of the minor U12-dependent spliceosome, is mutated in individuals with microcephalic osteodysplastic primordial dwarfism type I (MOPD I), a severe developmental disorder characterized by extreme intrauterine growth retardation and multiple organ abnormalities. Functional assays showed that mutations (30G>A, 51G>A, 55G>A, and 111G>A) associated with MOPD I cause defective U12-dependent splicing. Endogenous U12-dependent but not U2-dependent introns were found to be poorly spliced in MOPD I patient fibroblast cells. The introduction of wild-type U4atac snRNA into MOPD I cells enhanced U12-dependent splicing. These results illustrate the critical role of minor intron splicing in human development.  相似文献   

Effect of microfluidization on in vitro micellization and intestinal cell uptake of lutein from Chlorella vulgaris     

Cha KH  Lee JY  Song DG  Kim SM  Lee DU  Jeon JY  Pan CH 《Journal of agricultural and food chemistry》2011,59(16):8670-8674

Chlorella is a nutrient-rich microalga that contains protein, lipid, minerals, vitamins, and high levels of lutein. This study evaluated the bioavailability of lutein from Chlorella vulgaris using a coupled in vitro digestion and human intestinal Caco-2 cell model. Lutein bioaccessibility was low, and approximately 75% of total C. vulgaris lutein was not micellized during the digestion process but remained in the insoluble digestate. Microfluidization improved lutein micellization efficiency during C. vulgaris digestion. C. vulgaris was microfluidized at a pressure exceeding 10000 psi, and the cell surface disruption was visualized by scanning electron microscopy. The mean C. vulgaris particle size was reduced from 3.56 to 0.35 μm with the microfluidization treatment. C. vulgaris microfluidization at 20000 psi was three times more efficient for aqueous lutein micelles production as compared with untreated C. vulgaris, and the final lutein content accumulated by intestinal Caco-2 cells was also higher with microfluidization. C. vulgaris lutein stability was not affected by microfluidization. These results indicate that microfluidization may be useful for improving lutein bioaccessibility from C. vulgaris during food processing.  相似文献   

Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea     

Ji Hyung Kim  Sun Young Hwang  Jee Soo Son  Jee Eun Han  Jin Woo Jun  Sang Phil Shin  Casiano Choresca  Jr  Yun Jaie Choi  Yong Ho Park  Se Chang Park 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(1):41-48

The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser⁸³→Arg⁸³ or Ser⁸³→Asn⁸³. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida.  相似文献   

Analysis of methanogenic archaeal communities of rumen fluid and rumen particles from Korean black goats     

Min‐Jung GU  Md. Jahangir ALAM  Seon‐Ho KIM  Che‐Ok JEON  Moon‐Baek CHANG  Young‐Kyoon OH  Sang‐Cheol LEE  Sang‐Suk LEE 《Animal Science Journal》2011,82(5):663-672

Molecular diversity of methanogens in the rumen of Korean black goats was investigated with 16S rRNA gene clone libraries using methanogen‐specific primers. The libraries were composed of rumen fluid‐associated methanogens (FAM) and rumen particle‐associated methanogens (PAM) from rumen‐fistulated Korean black goats. Among the 141 clones of the FAM library, the sequences were mostly related to two phyla, the Methanobacteriaceae family (77.3%) and the Thermoplasmatales family (22.7%); and among the 68 clones of the PAM library, sequences were also mainly clustered in the two phyla, the Thermoplasmatales family (63.24%) and the Methanobacteriaceae family (35.29%). Most of the sequenced clones in the two libraries were closely related to uncultured methanogenic archaeon. Quantitative real‐time PCR revealed that PAM (8.97 log 10) had significantly higher (P < 0.01) density of methanogens by the methanogenic 16S rRNA gene copies than FAM (7.57 log 10). The two clone libraries also showed difference in Shannon index (FAM library 1.70 and PAM library 1.59) and Chao 1 estimator (FAM library 18 and PAM library 17 operational taxonomic units). Apparent differences found in the microbial community from the two 16S rRNA gene libraries could be a result of such factors as the chemical and physical nature of the target material surface, types or component of diets, the interaction between the methanogens and other microbes, and age of the experimental goats.  相似文献