Molecular typing of Streptococcus agalactiae isolates from fish

The genetic variability among Streptococcus agalactiae isolates recovered from fish was characterized using single-stranded conformation polymorphism (SSCP) analysis of the intergenic spacer region (ISR), and amplified fragment length polymorphism (AFLP) fingerprinting. A total of 46 S. agalactiae cultures isolated from different fish species and geographic origins as well as related reference strains were included in the study. ISR-SSCP divided the S. agalactiae isolates analysed into five distinct genotypes. Genotype 1 grouped all Kuwait isolates while genotype 4 clustered the majority of non-Kuwait isolates (USA, Brazil and Honduras). AFLP analysis offered a higher resolution level by dividing the isolates into 13 different genotypes. Two different AFLP profiles were identified within the Kuwait isolates. When data from both ISR-SSCP and AFLP were combined through a multidimensional analysis (MDS), a good correlation between geographical origin and genotypes was observed. Both AFLP and ISR-SSCP revealed genetic differences between S. agalactiae isolates from fish. While AFLP offered a higher resolution, ISR-SSCP also provided valid information being a simpler and faster method.     

白蜡杆软化和防蛀技术研究

白蜡(Fraxinus chinenesis)为木犀科(Oleaceae)白蜡树属(Fraxinus)的树种,落叶乔木或灌木。主要分布在西南、华中、华东、华北等地区。因白蜡杆木材具有材色浅、结构细、纹理直、软硬度适中、韧性好、可任意造型等优点,广泛用于农具、家具,特别适于弯曲部件、工艺品和文休用品的制作。自90年以来,以蜡杆、蜡条为主要原料生产高档工艺家俱的工作已经起步,但由于生产过程中缺乏合理实用的软化工艺及设备、防蛀工艺及设备,关键技术缺乏研究,不仅生产效率低,产品的内在质量无法改善,而且残次品率高,虫蛀率也高达80%以上。该研究提出了以蒸汽软化处理工艺、负压浸注防蛀工艺技术,既有效的软化了白蜡杆,同时达到了防蛀要求,产品的内在质量得到了改善。     

柚矮化病的品种感病性调查

以特征性症状春梢叶片扭曲畸形和枝条茎陷点为诊断依据，调查结果表明，５５个柚类品种中有２２个发病，占调查品种数的４０％；２８个沙田柚砧穗组合中有２２个发病，占调查砧穗组合数的７８．５％。以沙田柚实生苗和酸柚实生苗作指示植物，对温州蜜柑上的类似矮化病的叶片扭曲症状进行鉴定的结果，指示植物上表现出与接种沙田柚矮化病病原的指示植物相似的春梢叶片扭曲及茎陷点症状。     

知识经济与洛阳经济可持续发展

知识经济时代，洛阳经济可持续发展战略应该是：加大教育科研改革，全面实施“科教兴洛”战略，夯实知识经济的基础产业；扩大农业的知识资本投入量，促进农业产业化、企业化、资本化经营，实现农业知识化和现代化；得用新技术成果，对传统工业进行知识化改造，着力营造一批高新技术产亚，推动洛阳产业结构全面升级和优化。     

化隆县林草地鼠虫害调查及防治

就化隆县林草地带鼠虫害发生及防治情况进行了总结,指出了存在的问题,并就今后防治情况提出了建议。     

白花败酱组织培养及快速繁殖研究

选取长势较好、无病害野生白花败酱植株的茎尖及茎段作为外植体进行组织培养,以MS为基本培养基,设计不同激素浓度配比试验,筛选最佳培养基配方。结果表明:采用0.1%HgCl2对外植体进行消毒,茎尖最佳消毒时间为10 min,茎段为15 min;最佳诱导培养基配方是MS+6-BA 3.0 mg/L+NAA 0.1 mg/L,诱导率100%,增殖培养基MS+6-BA 2.0 mg/L+NAA0.2 mg/L,增殖倍数7.8;生根壮苗培养基是MS+NAA 1 mg/L+马铃薯5%。     

益生菌发酵乳无菌提取物对空肠弯曲杆菌flaA σ28启动子的抑制作用（英文）

为了研究益生菌发酵乳无菌提取物对食源性有害微生物(空肠弯曲杆菌)有毒基因表达的抑制作用,以利用空肠弯曲杆菌的有毒基因flaA σ28启动子和无启动子的质粒pRYluxCDABE联结构建的生物冷光转基因模型为试验材料,通过检测生物发光特性的方法,研究了空肠弯曲杆菌有毒基因flaA表达与益生菌(5种双岐杆菌,6种乳酸杆菌)发酵乳无菌提取物之间的关系。结果表明,益生菌发酵乳无菌提取物对空肠弯曲杆菌flaA σ28启动子的活性有显著的抑制作用(P<0.05),并可显著抑制空肠弯曲杆菌有害基因flaA的表达。     

灌溉水矿化度及盐分带入量对小麦相对产量影响的统计分析

在搜集、统计大量咸水灌溉试验资料的基础上,选取咸水充分灌溉条件下矿化度和小麦产量的完整对应数据103组,统计分析了灌溉水矿化度及单位面积盐分带入量对小麦相对产量的影响,结果表明,随着灌溉水矿化度的增加,小麦相对产量呈线性递减趋势,当矿化度大于1.0 g/L时,灌溉水矿化度每增加1 g/L,小麦减产约5.6%;与矿化度类似,随着单位面积盐分带入量的增加,小麦的相对产量也线性降低,盐分带入量每增加1000 kg/hm2,小麦的产量将减少约2%。进一步的检验结果显示,应用灌溉水矿化度及单位面积盐分带入量均可较为可靠地估算小麦的相对产量,估算相对误差基本可控制在16%以内。     

水稻机械割晒拾禾研究分析

建三江地区由于以往收获方式的单一,各种机械配置的不合理及农户对机械收获的认识不全面,收获条件差异等问题的存在,严重影响了水稻机械收获的进度。为了确保粮食保质保量的收获,通过对水稻割晒拾禾可行性、优越性、实施方案及可能存在的问题和注意事项的分析研究,在当地全面推广了水稻机械割晒和机械化直收相结合的收割方式,为实现水稻增产增收提供有利保证。     

Changes on carbohydrates and nitrogen content in the bark tissues induced by artificial chilling and its relationship with dormancy bud break in Prunus sp.

Stem cuttings of peach, nectarine, plum and apricot, obtained from 1-year-old shoots at leaf drop in autumn, were exposed at a constant 3.0 ± 0.1 °C to simulate different chilling accumulation treatments (0, 500, and 1000 chilling hours). A set of 10 excised shoots was forced to budbreak after chilling accumulation; a second set of 10 excised shoots was used to analyse sugars, starch, and ammonium-, nitric- and proteinaceous-nitrogen content in the bark tissues. Sorbitol, fructose and glucose were the main sugars in the bark tissues, whereas sucrose and rafinose showed the lowest quantities in all Prunus sp. studied. Sorbitol and starch concentration decreased whereas glucose and fructose concentration increased with chilling. Ammonium-nitrogen showed the more dramatic increase with medium chilling treatment, decreasing again at high chilling exposure. No modifications in proteinaceous- and nitric-nitrogen levels were observed due to chilling. Chilling treatments increasing flowering intensity showed high ammonium- and proteinaceous-nitrogen content in the bark tissues of the stem cuttings, whereas those reducing flowering intensity showed high starch and nitric-nitrogen content, in three of the four Prunus sp. studied. Ammonium-nitrogen content gives the highest correlation with flowering intensity.