红藤苗木施肥量的初步研究*

红藤(Daemonorops margaritae Hance)是我国主要商品藤种之一,目前已在广东、海南和福建等省推广人工栽培。红藤苗木培育周期长,从播种到成苗出圃约需一年时间,而壮苗技术是推广人工栽培的关键。为了研究红藤壮苗培育技术,在取得藤苗光照试验和矿质营养试验结果的基础上,安排了苗木施肥试验,以探求红藤苗木最适施肥量,为合理施肥提供科学依据。     

利用枣离体叶片直接再生完整植株

以冬枣组培苗叶片为材料进行离体再生培养, 通过对再生条件的系统研究, 实现了离体叶片直接再生不定芽并获得完整植株。试验结果表明: 麦芽糖为离体叶片直接再生的适宜碳源; AgNO3可显著提高叶片不定芽再生率和出芽数, 在TDZ 1.0 mg·L - 1 +AgNO3 1.0 mg·L - 1的条件下, 不定芽直接再生率高达97.3% , 出芽数达14.4个。但麦芽糖不适宜继续作为不定芽伸长培养的碳源, 再生的不定芽需在MS+ 蔗糖40 g·L - 1 + 琼脂4 g·L - 1 +BA 1.0 mg·L - 1 + IBA 0.5 mg·L - 1的培养基上进行增殖, 增殖系数为3.2。在IBA1.0 mg·L - 1条件下, 生根率达87.3%。     

侵蚀环境退耕撂荒地土壤活性有机碳与碳库管理指数演变

采用时空互代法,以典型侵蚀环境纸坊沟流域生态恢复过程中不同年限的撂荒地为研究对象,选取坡耕地和天然侧柏林为对照,分析了植被恢复过程中土壤有机碳(TOC)、活性有机碳(LOC)、非活性有机碳(NLOC)及碳库管理指数的演变特征.结果表明:侵蚀环境的坡耕地土壤碳库各组分含量较低,土壤碳库处于高速低效率运转;撂荒后可以显著增加土壤碳库各组分含量,并随恢复年限呈显著线性关系,50 a时,TOC、LOC和NLOC分别较坡耕地增加169%、144%和201%,为侧柏林的35%、39%和33%;碳库指数和碳库管理指数较坡耕地明显增加,增幅分别达到169%和117%,仅为侧柏林的35%和42%.表明坡耕地撂荒后,土壤碳库转化效率逐步提高,土壤管理经营更趋于健康科学,但相对于破坏前天然林水平还有很大的差距.有机碳、活性有机碳、非活性有机碳、碳库指数、碳库管理指数与土壤主要肥力因子密切相关,可以作为反映生态恢复过程土壤质量演变的指标.     

Pharmacokinetics of cefquinome in tilapia (Oreochromis niloticus) after a single intramuscular or intraperitoneal administration

The pharmacokinetics of cefquinome was studied in plasma after a single dose (10 mg/kg) of intramuscular (i.m.) or intraperitoneal (i.p.) administration to tilapia (Oreochromis niloticus) in freshwater at 30 °C. Ten fish per sampling point were examined after treatment. The data were fitted to two‐compartment open models following both routes of administration. The estimates of total body clearance (CL/F), volume of distribution (Vd/F), and absorption half‐life (T_1/2ka) were 0.049 and 0.037 L/h/kg, 0.41 and 0.33 L/kg, and 0.028 and 0.035 h following i.m. and i.p. administration, respectively. After i.m. injection, the elimination half‐life (T_1?2β) was calculated to be 5.81 h, the maximum plasma concentration (C_max) to be 49.40 μg/mL, the time to peak plasma cefquinome concentration (T_max) to be 0.14 h, and the area under the plasma concentration–time curve (AUC) to be 204.6 μg h/mL. Following i.p. administration, the corresponding estimates were 6.05 h, 44.39 μg/mL, 0.17 h and 267.8 μg h/mL. The minimum inhibitory concentrations of cefquinome, determined for 30 strains of Streptococcus agalactiae isolated from diseased tilapia, ranged from 0.015 to 0.12 μg/mL. Results from these studies support that 10 mg cefquinome/kg body weight daily could be expected to control tilapia bacterial pathogens inhibited in vitro by a minimal inhibitory concentration value of ≤2 μg/mL.     

SA+CaCl2对菊花花瓣生理和花期的影响

以不同浓度的水杨酸(SA+CaCl2)水溶液对菊花"兼六香菊"品种全株喷雾处理,测定整个花期花瓣中可溶性蛋白、可溶性糖含量、超氧化物歧化酶(SOD)活力、超氧阴离子(O2-)产生速率、丙二醛(MDA)含量以及相对电导率的变化.结果表明:不同浓度的SA+CaCl2均能提高花瓣中可溶性蛋白和可溶性糖含量、SOD活力和降低了O2-产生速率、MDA含量和相对电导率,花期有不同程度的延长,其中以SA 15 mg/L+CaC12160 mg/L处理效果较佳.     

基于解域的四精确点球面4R机构函数综合

提出了一种基于解域的四精确点球面4R机构函数综合方法.首先通过相对运动转换将函数综合转换为位置综合.接着给出了球面布氏曲线的方程式及布氏点的计算和分类方法.最后通过具体的示例建立了机构类型解域,将无穷多机构解表示在有限的环形区域内,从而使设计者能够直观准确地了解机构的类型及其分布区间.     

Effect of Different Plant Growth Regulators on Callus Induction and in vitro Rapid Propagation of Wild Petunia Juss.

In this study,the seeds of wild Petunia Juss.were used as explants to investigate the optimal condition for tissue culture.Several different kinds and concentrations of growth regulators were adopted to produce more multiple bud clumps,callus or roots in this study.The experiments may provide experimental foundation for the rapid propagation technology and establishment of tissue culture system for wild Petunia Juss.     

用水稻微卫星引物进行竹子分子系统学研究初探

竹子和水稻在进化上有较近的亲缘关系 ,本文利用水稻的微卫星引物对竹子的分子系统学进行了初步研究。与传统的分类结果不同 ,研究发现巴山木竹属是与青篱竹属相关属分化较大的 1个竹种 ,同时也证实了巴山木竹属作为 1个单独的属是成立的。研究也明确了茶秆竹的分类学位置。本研究从 1个不同的层面对青篱竹属相关属及属下一些竹种的关系提供了 1个新的研究结果 ,为利用现代分子生物学技术对广义青篱竹属的系统学研究提供了 1个借鉴。同时本研究对开展竹子的分子生物学研究提供了 1个崭新的思路和方法     

Antimicrobial Susceptibility and Characterization of Outer Membrane Proteins of Aeromonas hydrophila Isolated in China

Aeromonas hydrophila isolates from clinical cases （n=43） were tested against 8 antimicrobial agents and typed by outer membrane protein （OMP） pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin （MICs, ≥16 μg mL-1） and sulfamonomethoxine （MICs≥64 μg mLl）, but susceptible to norfloxacin （MICs,≤0.5 μg mL-1）. There was a high incidence of resistance to erythromycin （90.70%） and tylosin （93.02%）, while a low incidences of resistance to ciprofloxacin （2.33%）, enrofloxacin （2.33%） and florfenicol （4.65%）. Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.     

一株安徽株雏鸭肝炎病毒的分离与鉴定

从安徽省芜湖某养殖户送检的疑似鸭病毒性肝炎(DHV)的发病雏鸭肝等组织中分离到一株病毒,单称WHD。通过鸭胚接种分离到病毒。经动物试验显示,该病毒分离株的致死率达到70%。经过观察临床表现、剖检变化、血清被动保护试验,初步确诊所采集的病料均为鸭肝炎病毒。经和鸭胚中和试验证明,该病毒的血清型为Ⅰ型。