茶多酚对大鼠血管紧张素I转换酶(ACE)活性的影响

研究茶多酚对大鼠血管紧张素Ⅰ转换酶(angiotensinⅠconvertingenzyme,ACE)活性的影响。血管紧张素Ⅰ在ACE的作用下,通过脱去C端His-Leu二肽,转化为有生物活性的血管紧张素Ⅱ,从而产生强升压作用。通过体外试验和体内试验研究茶多酚对大鼠ACE活性的影响效应。试验结果表明,随着茶多酚摄入量的增加(45mg/kg,90mg/kg,180mg/kg),ACE活性显著降低(84.43±4.59u/μl,75.17±6.85u/μl,60.19±8.62u/μl,P<0.05)说明茶多酚对大鼠ACE有抑制作用,从而有可能起到降低血压的作用。     

家蚕超氧化物歧化酶(SOD)不同品种活性差异的研究

对西南农业大学家蚕基因库和育种室的114个家蚕品种及遗传系统进行了SOD活性调查，结果表明：SOD活性最高值达237.375U/ml，而最低值为38.372U/ml，平均值为140.08U/ml；品种间SOD活性差异较大，其品种及遗传系统的活性值分布图似正态分布，而一代杂交种的活性值居双亲活性值中间，并推测SOD活性受多基因支配，但也有主基因作用。中国二化性品种SOD活性值比日本二化性品种高20％左右。     

The potential role of PR-8 gene of apple fruit in the mode of action of the yeast antagonist,Candida oleophila,in postharvest biocontrol of Botrytis cinerea

Several pathogenesis-related (PR) genes of apple have been cloned and their response to different pathogens has been studied. Different PR genes, however, may have a variable response depending on the specific organ or tissue as well as microbe. The objective of the current study was to characterize the expression of specific apple PR genes in fruit tissues in response to the antagonistic yeast, Candida oleophila (a common postharvest biocontrol agent), and the fungal pathogen, Botrytis cinerea (a major postharvest pathogen). Apple PR-5 and PR-8 gene expression was characterized in fruit in response to C. oleophila and B. cinerea. Results indicated that PR-8 expression was significantly elevated in response to both fungi. In contrast, neither C. oleophila nor B. cinerea treatment markedly affected PR-5 expression. The PR-8 gene was then synthesized and cloned into a Pichia pastoris expression system to study the antifungal activity of the PR-8 protein against B. cinerea both in vitro and in vivo. Collectively, the PR-8 gene of apple is associated with the response to B. cinerea infection, and may play a role in the mechanism by which C. oleophila effectively inhibits B. cinerea disease in apple fruit, namely by the induction of this specific host PR gene.     

联肼·乙螨唑对蔬菜优势叶螨产卵发育的影响及其田间防效

为明确新型复配杀螨剂联肼·乙螨唑对目前蔬菜田常发生的2种优势叶螨二斑叶螨Tetranychus urticae和截形叶螨T. truncatus的杀螨活性,于室内采用离体叶碟法测定其对这2种叶螨产卵及发育的影响,于室外采用活体植株评价该药剂对2种叶螨的田间防效。结果表明,经复配杀螨剂联肼·乙螨唑及其单剂处理2种叶螨雌成螨24 h后,死亡率为20.50%～54.98%,均显著高于清水对照;联肼·乙螨唑处理较清水对照显著降低了2种叶螨卵发育至若螨期的比率,联肼·乙螨唑处理后二斑叶螨和截形叶螨的若螨率分别为4.91%和1.63%。田间试验中联肼·乙螨唑对2种叶螨具有一定的速效性,药后3 d对二斑叶螨和截形叶螨的防效分别达95.74%和89.83%,药后7 d防效分别为98.03%和99.44%,显示了优良的防控效果及持效性。表明复配杀螨剂联肼·乙螨唑可用于田间蔬菜优势叶螨种群的高效防控。     

黄瓜自根苗、嫁接苗根系活力、净光合速率和蛋白质表达差异研究

将黄瓜津优1号、津优1号与黑子南瓜的嫁接苗和黑子南瓜种在网室中的消毒泥炭钵内,用LI-6400光合系统和2D-E电泳技术分析了这3种处理的根系活力、净光合速率和蛋白质的表达差异。结果表明,黑子南瓜的根系活力强于嫁接苗黄瓜,嫁接苗黄瓜的根系活力又强于自根苗黄瓜。在光量子通量密度低于500μmol.m-2.s-1时,嫁接黄瓜和黑子南瓜的净光合速率高于自根苗黄瓜,当光通量子密度超过500μmol.m-2.s-1后,嫁接黄瓜和黑子南瓜的净光合速率则低于自根苗黄瓜。当CO2浓度低于400μmol.mol-1时,嫁接黄瓜与自根苗的光合速率相当,CO2浓度超过400μmol.mol-1后,嫁接黄瓜的光合速率超过了自根苗。黑子南瓜的光合速率在50~600μmol.mol-1的CO2浓度范围内最高,然后下降,并间于嫁接黄瓜和自根苗黄瓜之间。嫁接的津优1号黄瓜有5个蛋白质的表达量增强了,同时也产生了5个新的蛋白质。     

Effectiveness of submicron chitosan dispersions in controlling anthracnose and maintaining quality of dragon fruit

Conventional chitosan (CC) and submicron chitosan dispersions (SCD) were evaluated for the control of postharvest anthracnose and maintenance of quality of dragon fruit during storage at 10 ± 2 °C and 80 ± 5% RH for 28 days. All the chitosan treatments significantly reduced anthracnose symptoms, resulting in a reduction of disease development and thereby maintained the quality of fresh fruit for extended periods. SCD at 1.0% with 600 nm droplet size gave the best result in that it delayed the onset of disease and maintained the quality of dragon fruit for up to 28 days of storage. It can be concluded from the present investigation that SCD have potential to be used as an antifungal agent to control postharvest anthracnose and maintain quality of dragon fruit during storage.     

绵羊食管、网胃和瘤胃电活动的研究

用RM-6008型记录仪记录了绵羊在安静、进食、反刍和嗳气等状态下的食管、网胃和瘤胃的前背囊、后背盲囊、后腹盲囊、前腹囊的电活动及其先后次序。结果表明:食管电呈群集型,只在进食、嗳气和反刍时出现。在各种生理状态下,网胃电最先出现,波型随生理状态不同而有差异。瘤胃电由第一次波(P波)和第二次波(S波)组成;P波开始于网胃电活动之后,出现频率与网胃电频率相同,其活动次序为,前背囊→后背囊→后腹盲囊→前腹囊,有时电活动止于后背盲囊;S波位于P波之后,其频率低于P波,且与进食和嗳气有关;进食时,S波出现频率最高,其活动次序是,前腹囊→后腹盲囊→后背盲囊→前背盲囊;嗳气时,S波活动次序是,后腹盲囊→后背盲囊→前背囊;安静和反刍时的活动次序与嗳气时相似。     

秋季中华蜜蜂（Apis cerana cerana）工蜂有分泌活性的舌腺和无分泌活性的舌腺的超微结构比较

对秋季中华蜜蜂工蜂有分泌活性舌腺（９日龄）和无分泌活性的舌腺（采集蜂）的超微结构进行了观察和比较，发现二者的舌腺细胞的超微结构存在着差异。９日龄工蜂舌腺处在分泌活性状态。细胞核发达，多突起；粗面内质网发达，成平行状排列；胞内管、胞外管中都充满电子致密度均匀的物质，即王浆物质；有大量的分泌块；线粒体内嵴排列紧密，呈板层状。而采集蜂舌腺处在无分泌活性状态。核周边异染色质增多；粗面内质网不太发达，多呈泡状；胞内管中物质为一些不均匀的电子致密度大的粗颗粒物质；胞外管中只有少量水样物质；线粒体内嵴间隙相对变大，多发现内嵴间隙呈管泡状。     

细胞外环境中分化抑制物对动物胚胎干细胞克隆率的影响

介绍了饲养层、条件培养基、分化抑制因子对哺乳动物胚胎干细胞分离与克隆的影响，并探讨了白血病抑制因子影响胚胎干细胞克隆的机理。     

Comparative Analysis of Photosynthetic Parameters and its Evaluation in Pearl Millet Hybrid and its Parents

Fully expanded leaf occupying topmost position in a field grown pearl millet hybrid (BJ-104) and its parents (J-104 and 5141-A) were analysed at weekly intervals for chlorophylls, Hill activity and phosphoenolpyruvate carboxylase activity. Large ontogenic drifts in these parameters, made the actual comparison between hybrid and parents, difficult. However, up to 52 d the hybrid leaf possessed considerably higher chlorophyll pigments than its parents. Amongst the inbreds, the male parent was initially better than the female parent while at later stages, the trend was reversed. Hill activity and PEPcase were more in the male than in the female parent and the hybrid followed the better parent. Rate limiting steps for productivity, measured as NAR (g dry weight)⁻¹, were worked out in the female parent, using multiple regression and correlation analysis, and the significance of such an analysis is discussed in relation to plant productivity.