几种鲤、鲫鱼腹膜色素细胞的初步观察

通过普通鲫、普通鲤、红鲫、荷包红鲤、水晶彩鲫和锦鲤的腹膜脏层和腹膜壁层色素细胞观察,腹膜脏层分布有黑色素细胞,其中普通鲫致密完整,普通鲤和红鲫密集均匀,水晶彩鲫和锦鲤缺失,荷包红鲤完全缺失;腹膜壁层分布有鸟粪素细胞,除水晶彩鲫缺失,其它品种致密完整。     

超临界流体技术在生物资源活性成分萃取中的应用及展望

综述了超临界流体技术的萃取原理、应用范围、特点、分类和国内外研究现状,以及在生物活性成分提取中的应用情况;分析了超临界流体技术的局限性及存在的问题,并对其在虫草属真菌生物活性成分上的应用前景进行了展望.为进一步开发虫草资源提供参考.     

Identification and Expression of a β-actin Gene from Liposcelis bostrychophila Badonnel （Psocoptera： Liposcelididae）

A β-actin gene, Libβ-actinl, from the psocid, Liposcelis bostrychophila, was isolated, sequenced, and expressed in Escherichia coli. The cDNA sequence was 1 281 bp in length and contained an open reading frame of 1 131 bp encoding 376 amino acids with a predicted molecular weight of 41.82 kDa. According to a BlastN search, the coding region shared the highest identity (97%) with Pediculus humanus actin 5C, while the deduced amino acid sequence was completely identical to a mutant of Drosophila melanogaster actin 5C. Comparison of the nucleotide and deduced amino acid sequences confirmed the high similarity between Libβ-actinl and homologs in other insect species. The 3′ untranslated region (3′ UTR) of the Libβ-actinl mRNA had a high A+U content (approximately 75%) and contained three repeats of the AUUUUUA and AUUUA motifs, which may play a role in regulating mRNA decay. The expression of Libβ-actinl was further analyzed in insecticide induced and control psocids. The results indicated that there was no significant difference in expression of Libβ-actinl between the induced and control groups, suggesting that Libβ-actinl may be an appropriate internal control for the gene expression profiling in this insect. Furthermore, Libβ-actinl was also heterologously expressed in Escherichia coli, which provided a basis to investigate the physiological functions of actin genes in the psocid.     

垫江白柚贮藏生理及防止粒化方法研究

 研究了冷激处理、药剂处理对垫江白柚果实生理代谢及相关酶活性的影响。结果显示：冷激可显著抑制柚果的呼吸强度,冷激和药剂处理均可有效降低无氧呼吸产物乙醇,膜脂过氧化产物丙二醛(MDA)的累积速率,另外可增加果皮POD酶活性,改变其酶活性变化趋势,使纤维素酶在贮藏中前期维持较低的水平,推迟粒化出现的时间,减轻发生的程度。     

枣棉间作条件下棉花密度对棉花光合特性及产量影响

在枣棉间作条件下,通过设置不同的棉花种植密度(13.5万、18.0万和22.5万株·hm-2),研究了密度对棉花光合作用及产量的影响。结果表明,间作棉花形态、荧光参数和光合特性受到枣树的显著不利影响,表现出明显的边行负效应。随着枣棉间距离的增加,不利影响减小,SPAD值、光系统II的实际光化学效率(ΦPSII)和净光合速率(Pn)显著增加;随着密度增加,间作棉花LAI和干物质质量显著增加。密度为18万株·hm-2的间作棉花的光系统II的实际光化学效率(ΦPSII)、净光合速率(Pn)、蒸腾速率(Tr)和产量显著高于13.5万株·hm-2和22.5万株·hm-2。在枣棉间作复合系统中,适当增加枣棉间距可以减轻枣树对棉花的不利影响,而较高的棉花密度也有利于棉花高产。     

Rapid quantification of plant-powdery mildew interactions by qPCR and conidiospore counts

ABSTRACT: BACKGROUND: The powdery mildew disease represents a valuable patho-system to study the interaction between plant hosts and obligate biotrophic fungal pathogens. Numerous discoveries have been made on the basis of the quantitative evaluation of plant-powdery mildew interactions, especially in the context of hyper-susceptible and/or resistant plant mutants. However, the presently available methods to score the pathogenic success of powdery mildew fungi are laborious and thus not well suited for medium- to high-throughput analysis. RESULTS: Here we present two new protocols that allow the rapid quantitative assessment of powdery mildew disease development. One procedure depends on quantitative polymerase chain reaction (qPCR)-based evaluation of fungal biomass, while the other relies on the quantification of fungal conidiospores. We validated both techniques using the powdery mildew pathogen Golovinomyces orontii on a set of hyper-susceptible and resistant Arabidopsis thaliana mutants and found that both cover a wide dynamic range of one to two (qPCR) and four to five (quantification of conidia) orders of magnitude, respectively. The two approaches yield reproducible results and are easy to perform without specialized equipment. CONCLUSIONS: The qPCR and spore count assays rapidly and reproducibly quantify powdery mildew pathogenesis. Our methods are performed at later stages of infection and discern mutant phenotypes accurately. The assays therefore complement currently used procedures of powdery mildew quantification and can overcome some of their limitations. In addition, they can easily be adapted to other plant-powdery mildew patho-systems.     

菠萝老茎留苗地间种甘蔗技术研究

以摘果后的常规菠萝老茎留苗地为试验地,以菠萝老茎留苗与甘蔗种进行间种．探讨和研究不同间种规格和方法对菠萝老茎所留种苗数量、质量（种苗合格率）以及甘蔗产量的影响．并与常规技术的经济指标做了对比分析。结果表明：采用菠萝老茎留苗地间种甘蔗技术,以菠萝大行距间为种植沟,实施隔行间种甘蔗．该技术能使老茎留苗地菠萝留苗平均可达12．81万株／hm^2,种苗合格率占94．8％,平均可产甘蔗种31．95t／hm^2以菠萝大行距间为种植沟,实施连行间种甘蔗技术,菠萝种苗留苗的数量相对减少。种苗合格率占93．6％．平均每公顷可摘种苗8．30万株．平均可产甘蔗种42．00t／hm^2。菠萝种苗数减少．但甘蔗产量增加。两种不同的间种规格和方法对留苗和砍种都有各自的效果．与常规菠萝老茎留苗技术相比．菠萝老茎留苗与甘蔗种间种技术总体经济效益显著．     

基于SOR模型的高校图书馆员行为对读者参与的影响实证研究

[目的/意义] 厘清图书馆行为与读者情感、读者参与之间的影响关系,可以帮助图书馆对图书馆员行为进行有效管理,激发读者正向情感,鼓励读者积极参与,从而提高读者满意度和图书馆的竞争力。 [方法/过程]文章以广东药科大学图书馆为例,引入SOR模型,构建了“图书馆员行为—读者情感—读者参与”的影响关系模型,并运用SPSS软件的回归模型实证分析了图书馆员行为对读者参与的影响程度,及读者情感在图书馆员行为和读者参与的中介作用。[结果/结论]分析结果显示,图书馆员行为对读者参与具有显著正向影响,图书馆员行为对读者情感具有显著影响,读者情感对读者参与有显著影响,读者情感在图书馆员行为与读者参与之间具有中介作用。     

蛋种鸡场中性电解水带鸡喷雾消毒试验研究

养殖场的定期消毒是工程防疫的一项重要措施。该文针对强酸性电解水（高氧化还原电位水）的低pH值 （＜2.7）、腐蚀性大、制造成本高、不适合畜禽养殖中的应用等问题,试验研究了中性电解水（pH 6.5～8.5）与常用消毒剂（速洁和聚维酮碘等）对蛋种鸡场的带鸡喷雾消毒效果。考察了不同有效氯浓度、风机停开时间（作用时间）和喷嘴直径下中性电解水对鸡舍空气的杀菌效果。结果表明,不同作用时间下,中性电解水带鸡喷雾消毒效果均优于含过氧乙酸/双氧水的速洁消毒剂和聚维酮碘,且消毒效果随着有效氯浓度的升高而增强;较小的喷嘴直径（50 μm）带鸡喷雾消毒,可以提高有效氯利用率,对空气的杀菌率高。采用有效氯浓度为160 mg/L及以上的中性电解水带鸡消毒,喷雾结束后风机停开5 min具有较好的消毒效果。因此,中性电解水可以用于种鸡舍带鸡消毒,对发展无害化绿色健康养殖具有重要意义。