我国主要栽培木薯品种体细胞胚胎发生与芽器官发生的研究

本研究对我国10个木薯(Manihot esculenta Crantz)主要栽培品种离体培养,研究结果表明不同品种之间在体细胞胚胎发生和器官发生的能力上因基因型不同而差异显著.以组培苗茎段侧芽或顶芽为外植体,在添加Picloram和2,4-D的体细胞胚胎发生诱导培养基上暗培养2周后,可诱导胚状体的形成.生长素浓度中,2,4-D在6mg/L及Picloram在12mg/L为最佳使用浓度,并且Picloram的效果明显优于2,4-D.NZ188、SC124和SC205体细胞胚胎发生的频率可达到80%以上.诱导的胚状体经循环继代培养可形成次生胚状体.次生胚状体在成熟培养基上经2～3周的光培养可形成绿色子叶的体细胞胚,进而萌发形成再生植株.NZ188及SC8体细胞胚萌发频率最好,可达80%以上.以培养2周的子叶胚切块置于体细胞胚胎发生诱导培养基上可诱导形成次生胚状体,诱导频率都在77%以上.子叶胚切块置于器官发生培养基上可诱导芽器官发生,2周后可形成芽原基及不定芽,诱导频率在34.4%到72.2%之间,其中NZ188、NZ199和SC124诱导效果较好.再生培养附加乙烯抑制剂AgNO_3可明显抑制愈伤组织的形成,提高芽器官发生的能力,包括再生频率及芽再生的数目,浓度以4 mg/L为宜.从含AgNO_3的培养基上再生的芽有利于进一步生长和移栽成活.     

鲢即刻早期基因c-fos和c-jun的克隆及其序列分析

原癌基因c-fos和c-jun 属于即刻早期基因,在神经元兴奋传导和中枢神经系统活动过程中起着重要作用。通过ＲＡＣＥ技术首次克隆了鲢（Ｈｙｐｏｐｈｔｈａｌｍｉｃｈｔｈｙｓｍｏｌｉｔｒｉｘ）肝脏c-fos和c-jun基因,通过生物信息学方法预测分析了该基因的结构和功能。结果表明,鲢肝脏c-foscDNA 全长为1719bp,开放阅读框1059bp,编码３５２个氨基酸;ｃ-jun cDNA全长1931bp,其中开放阅读框９２７ｂｐ,编码３０８个氨基酸;二级结构预测可知,c-fos 包含２５．８５％的α-螺旋,１２．７８％的延伸链,１．４２％的β 折叠和５９．９４％的无规则卷曲;ｃ-ｊｕｎ包含３２．１４％的α-螺旋,５．５２％的延伸链,１．６２％的β-折叠和６０.７１％的无规则卷曲。分析其功能结构位点,发现在１０８～１７２aa 和２２７～２９１aa处有１个典型的亮氨酸拉链结构。通过构建氨基酸系统发育树,鲢与草鱼（Ｃｔｅｎｏｐｈａｒｙｎｇｏｄｏｎｉｄｅｌｌｕｓ）c-fos同源性高达９７％,与草鱼c-jun同源性高达９５％,而与哺乳动物同源性较低。     

鲢鱼生物学性状研究

鲢鱼又名白鲢、跳鲢、鲢子鱼等。属鲤科、鲢亚科。鲢鱼具有生长快、疾病少、不需专门人王投饵的特点。利用鲢鱼实测体全长,体重数据进行线性回归分析,得出鲢鱼的体全长和体重之间呈曲线相关关系,相关公式为W=0.011L^3.077R=0.9919。     

银黑狐优化结构模型的建立与经济效益的分析研究

毛皮动物是一个动态群体，依年龄、性别的差异，运用莱斯里、投入产出模型等，对其动态结构进行分析优化，提高了饲养场的经济效益。本文以银黑狐为例建立优化结构模型．     

Antimicrobial gelatin nanofibers containing silver nanoparticles

Gelatin is one of the most promising biomaterials due to its excellent biocompatibility and biodegradability. In order to improve the antimicrobial activity of gelatin, gelatin nanofibers containing silver nanoparticles were prepared by electrospinning gelatin/AgNO₃/formic acid system, followed by UV irradiation. They were characterized by UV-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis. It was observed that the silver nanoparticles, which presented quasi-sphere shaped and 9–20 nm average diameters, were generated on the surface of the gelatin nanofibers. The size of the silver particles can be adjusted by changing the content of AgNO₃. With increasing the amount of AgNO₃, the average diameters of fibers decreased. The gelatin-Ag nanocomposites were found effective against Staphylococcus aureus and Pseudomonas aeruginosa. From these results, it is expected that the electrospun antimicrobial gelatin nanofiber mat can be used as an excellent wound dressing.     

用超敏感银染SDS-PAGE方法绘制黄瓜、菜豆蛋白质指纹图谱

利用超敏感银染ＳＤＳ－ＰＡＧＥ方法对黄瓜胚轴和菜豆胚轴、胚根组织的全蛋白指纹图谱作了初步分析,黄瓜胚轴至少有４０条蛋白质谱带被检测到;黄豆胚轴中有５０多条、胚根６０多条蛋白质谱带被检出,谱带清晰、稳定,个体间谱型一致,且分离过程短,减少了蛋白质的部分变性和损失,结果较全面。     

高粱微卫星非变性聚丙烯酰胺凝胶电泳条件的优化

以高粱抗、感丝黑穗病3号生理小种部分品种(S95062B、7050B、2381R、LR625;622A、622B、矮4)为材料,利用微卫星标记结合非变性聚丙烯酰胺凝胶电泳技术进行抗病基因的引物筛选.通过比较各因子对电泳体系的影响,建立了一个高粱微卫星非变性聚丙烯酰胺凝胶电泳的优化体系:电泳时间为92～105 min;银染温度为27.8～29.0 ℃;显色温度为32℃左右.     

刺槐林地空气负离子水平

对北戴河联峰山公园刺槐林地内空气负离子水平进行了观测,结果表明:空气负离子密度在1d内存在2个波峰和2个波谷交替变化的规律,波峰分别出现在7:00—11:00、16:00—17:00,波谷出现在11:00—13:00、23:00—1:00。7月份空气负离子密度明显高于其它月份,峰值达到1508个/cm3,且空气负离子密度以7月份为中心呈单峰曲线分布。相关性分析表明,空气负离子密度与温度呈负相关关系,与相对湿度呈正相关关系。     

Winter Feeding and Growth of Channel Catfish Fed Diets Containing Varying Percentages of Distillers Grains with Solubles as a Total Replacement of Fish Meal

Channel catfish, Ictalurus punctatus, with an average initial weight of 515g, were fed four experimental pelleted diets (1-4) with increasing percentages (0, 35, 55, or 90%) of distillers grains with solubles (DGS) during the winter. A fifth diet was formulated identical to diet 4 except that 0.6% supplemental lysine was added to meet the published requirement. Yield, individual weight, individual length, survival, and weight gain of fish were not significantly different (P > 0.05) among treatments. Average individual fish weight at harvest was 542 g and represented a weight gain of 5.4%. Percentage moisture, protein, and fat of waste, (skin, head, and viscera) were not significantly different (P . 0.05) among treatments. Percentage protein of the dressed carcass of fish fed diet 4 (90%) DGS without lysine) was significantly lower (P < 0.05) than in fish fed diet 3 (55% DGS), and percentage fat was significantly lower (P < 0.05) than in fish fed diet 5 (90% DGS + 0.6% lysine). These data indicate that DGS is a suitable diet ingredient and can be used at levels up to 90% inclusion in winter diets for channel catfish without addition of supplemental amino acids. Use of DGS in diets may be economical, especially if prices of fish meal and soybean meal increase dramatically or if DGS is locally available.     

The use of eugenol against Aeromonas hydrophila and its effect on hematological and immunological parameters in silver catfish (Rhamdia quelen)

The aim of this study was to evaluate the activity of eugenol against the fish pathogen Aeromonas hydrophila and eugenol's effect on hematological and natural immune parameters in silver catfish (Rhamdia quelen). In vitro, eugenol showed weak activity against A. hydrophila, but in vivo, at a subinhibitory concentration (10 mg L^?1), it promoted survival in infected silver catfish. Eugenol (50 μg mL^?1) reduced the hemolytic activity of A. hydrophila supernatant in vitro in fish erythrocytes. Subjecting catfish to eugenol baths (5 and 10 mg L^?1) for five days did not alter the hematological and immunological parameters studied in this work. Based on these results, eugenol can be used to treat or prevent bacterial diseases in fish.