星斑川鲽MHCⅡ恒定链Ii基因的克隆和表达特性

为了研究星斑川鲽MHCⅡ类分子的作用及调控机制,实验通过SMART-RACE技术克隆得到了星斑川鲽MHCⅡ恒定链(MHCⅡIi)的全长cDNA序列,其长度为1766 bp,包含135 bp的5′非编码区、837 bp的开放阅读框和794 bp的3′非编码区。该基因共编码279个氨基酸。理论分子量为30.848 ku,等电点为6.89。与已知物种MHCⅡIi进行同源性比对,结果与狼鲈、紫红笛鲷和鳜关系较近,同源性均为79%。利用quantitative realtime PCR(qRT-PCR)技术检测了MHCⅡIi在星斑川鲽不同组织中的表达,以及爱德华氏菌感染前后对该基因在不同组织中表达水平的影响,结果显示:在脾脏、头肾、肝脏、后肠、性腺、心脏、血液、鳃和肌肉组织中,MHCⅡIi mRNA均有表达,但在表达量上有明显差异,脾脏和头肾组织相对表达水平较高,鳃、血液、肌肉、心脏和性腺中的表达水平较低。病原感染后,免疫相关组织脾脏和头肾的表达水平升高最明显,肝脏和后肠的表达水平也略有升高,但变化不明显。本研究可为星斑川鲽MHCⅡ类分子的作用机理提供理论依据,同时为海水养殖鱼类的抗病遗传育种工作提供研究基础。     

Monitoring the photosystem II behavior of wild and cultivated barley in response to progressive water stress and rehydration using OJIP chlorophyll a fluorescence transient

To study the effects of progressive drought stress on photosystem II behavior of wild type (Spantaneum) and cultivated barley (Morocco), different levels of soil water availability, including control, moderate, mild, and severe water stress (70%, 50%, 30%, and 10% water holding capacity of soil, respectively) and rehydration were used. Polyphasic OJIP fluorescence transient of Morocco plants exhibited a considerable increase in fluorescence intensity at O, J, and I steps under mild and severe stress relative to slight increase in wild barley. Values of fluorescence parameters and quantum efficiencies, including minimal fluorescence, relative variable fluorescence at phase J and I, maximal quantum yield of photosystem II (PSII), performance index, electron transport yield, and excitation transfer efficiency were influenced by water stress in both genotypes. These parameters were significantly less affected in wild type barley by progressive drought stress compared to Morocco. After re-watering, both genotypes were able to restore from severe drought in most of the traits. Based on our findings, highly correlated values of relative water content (RWC) and independent JIP-test parameters (P < 0.01) indicate that the chlorophyll a fluorescence induction technique is sensitive to plant water status and performance index represent an accurate and reliable indicator for early stress detection and also explore plant vitality under water stress.     

Cryptic species composition and genetic diversity within Bemisia tabaci complex in soybean in India revealed by mtCOI DNA sequence

Bemisia tabaci is a cryptic species complex, causing significant loss on many agriculturally important crops worldwide. Knowledge on species composition and diversity within B. tabaci complex is critical for evolving sustainable pest management strategies. Here we investigate the whitefly species complex in soybean in major soybean growing states of India. The mitochondrial cytochrome oxidase gene subunit-1(mt COI) based phylogenetic relationships established using Bayesian methods indicated the existence of three cryptic species namely AsiaⅠ, AsiaⅡ1, and AsiaⅡ7. All the haplotypes detected in the study could be assigned to these three cryptic species following the species demarcation criteria of 3.5% divergence threshold. Of these, AsiaⅡ1 was found to be predominant with wide spread distribution across the surveyed regions from cool temperate zones to hot and humid tropical plains. On the contrary, cryptic species AsiaⅡ7 showed localized distribution. The AsiaⅡ1 exhibited the highest haplotype diversity and AsiaⅠ showed high level of nucleotide diversity. There was a significantly high genetic differentiation among these three cryptic species. The MEAM 1, a dreadful invasive species was not detected in the specimens tested in the current study. The diversity and distribution of three cryptic species is discussed in the light of current knowledge on distribution of whitefly species in India and yellow mosaic disease observed during sampling survey.     

新型钴配合物为中性载体的水杨酸根电极研究

研究了基于水杨醛缩邻氨基苯酚合钴(Ⅱ)金属配合物[Co(Ⅱ)-SAAP]为中性载体的PVC膜阴离子电极。该电极对水杨酸根(Sal-)具有优良的电位响应性能和选择性并呈现出反Hofm e ister选择性行为,其选择性次序为Sal->C lO4->SCN->I->NO2->NO3->B r->C l->SO32->SO42-。在pH为5.0的磷酸盐缓冲体系中,电极电位呈现近能斯特响应,线性响应范围为9.0×10-6~1.0×10-1mol/L,斜率为-54.3 mV/dec(20℃),检出下限为5.0×10-6mol/L。采用交流阻抗技术和紫外可见光谱技术研究了电极的响应机理,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之间有非常密切的构效关系。该电极具有响应快、重现性好、检出限低、制备简单等优点。将电极用于药品分析,其结果令人满意。     

Feasibility test of HBH Ⅱ compound microorganism on the reduction of septic tank nightsoil sludge 

The paper selects septic tank nightsoil sludge as the study object, and conducts three treatments for nightsoil sludge anaerobic digestion reduction under 35 ℃ including CK treatment(without HBH II compound microorganism), T1 treatment(adding 0.005% HBH II compound microorganism in the original nightsoil sludge system) and T2 treatment(adding 0.005% HBH II compound microorganism after the nightsoil sludge was sterilized by pasteurism). It investigates the removal rate of total solid (TS), volatile solid (VS) and COD of the three treatments, and analyzes the main contents of nightsoil sludge before and after anaerobic digestion and the digestion efficiencies of them. The results indicate that the removal rates of TS, VS and COD of T1 are 46.03%, 49.96% and 47.06%, respectively, and there are 14.89%, 16.26% and 15.53% higher than CK, 6.63%, 8.02% and 11.90% higher than T2, respectively. There are significantly positive (p<0.01) relations between T1 and CK, and T1 and T2 in the removal rate of TS, VS and COD. The nightsoil sludge digestion efficiencies of CK, T1 and T2 are 34.69%, 51.09% and 43.05%, respectively and that of T1 significantly positive(p<0.01) differs from CK and T1 treatment. The results indicate that the corporate effect of the adding HBH II compound microorganism and the original microorganism of the nightsoil sludge system are helpful to the reduction of septic tank nightsoil sludge and it is feasible for directly adding HBH II compound microorganism to septic tank for the reduction of the nightsoil sludge in it.     

烟草蛋白研究进展

从烟草中提取烟草蛋白,是解决目前动物蛋白紧缺问题的有效途径之一。介绍了烟草蛋白的组成与特性,分析了烟叶作为蛋白来源的潜力,综述了国内外烟草蛋白分离纯化技术的研究进展,讨论了影响烟草蛋白制备的主要因素,并对烟草蛋白的开发利用进行了展望。     

凹凸棒土对Cd（Ⅱ）的吸附性能研究

采用凹凸棒土对废水中的Cd（II）进行吸附试验,探讨了吸附时间、凹凸棒土投加量、废水中Cd（II）的初始浓度对吸附率的影响,探索最佳工艺条件;同时考察了酸化改性后凹凸棒土对Cd（II）的吸附性能,并分析了凹凸棒土对Cd（II）的吸附等温线。结果表明Cd（II）的初始浓度越高,吸附率越低;Cd（II）在浓度为20 mg/L、吸附时间60 m in、凹凸棒土投加量60 g/L时,去除率达到94.6%;盐酸改性后,Cd（II）在浓度为20 mg/L、吸附时间60 m in、凹凸棒土投加量40 g/L时,吸附率达93.5%,当凹凸棒土投加量为60 g/L时吸附率达98.2%;从拟合吸附等温线相关性系数来看,Langmuir方程能更好地描述吸附过程中凹凸棒土对Cd（II）的吸附。     

Resistance monitoring of Heliothis virescens to pyramided cotton varieties with a hydrateable, artificial cotton leaf bioassay

Proof of concept was demonstrated for a practical, off-the-shelf bioassay to monitor for tobacco budworm resistance to pyramided Bt cotton using plant filtrates. The bioassay was based on a previously described feeding disruption test using hydrateable artificial diet containing a blue indicator dye, a diagnostic dose of insecticide and novel assay architecture. Using neonate larvae from a Bt-susceptible, laboratory reared tobacco budworm strain, a diagnostic dose for Bollgard II and WideStrike cotton was obtained that limited neonate blue fecal production to 0-2 pellets in 24 h (Bt-resistant larvae produced >2 fecal pellets). The bioassay was tested with three different field populations of tobacco budworm collected from tobacco in central North Carolina (USA) and shown to accurately diagnose susceptibility to Bt. The diagnostic doses were also successfully evaluated with two Bt-resistant, laboratory reared tobacco budworm strains. Shelf life studies showed the assay could be stored for at least 6 months at room temperature (longer storage times were not studied). The application of the bioassay as an easy to use monitoring tool is discussed.