钙对西瓜幼苗生长、光合特性及保护性酶活性的影响

采用营养液水培方式,以‘早佳(8424)’西瓜为试材,研究了不同钙浓度水平对西瓜幼苗生长、光合特性及保护性酶活性的影响。结果表明:0和50mg/L钙处理的幼苗生长缓慢,POD、SOD活性显著高于其它处理;220mg/L处理的生长速度最快,株高最高;190mg/L处理的叶片数、植株鲜重、干重、根系长度,净光合速率Pn、气孔导度Gs、胞间CO2浓度Ci、叶绿素含量显著高于其它处理。因此,在0～220mg/L钙浓度范围内,提高营养液中钙离子浓度,可以促进植株生长,增强光合作用,增加有机物的合成与积累。     

细胞色素C氧化酶的纯化及动力学性质研究

采用硫酸铵分级沉淀和CytochromeC -Sepharose 4B亲和层析 ,从牛心线粒体中纯化了细胞色素C氧化酶 (CytochromeCOxidase ,简称CCO ) ,其比活性为 1 7 88s- 1 ·mg- 1 ,聚丙烯酰胺凝胶电泳为一条带 ,血红素A (HemeaA)含量达到 1 5 4nmol/mg。纯化后的CCO具有典型的CCO特征 ,还原态CCO峰值出现在 60 5nm和 443nm ,氧化态CCO峰值出现在 598nm和 42 4nm。CCO的稳态动力学参数Vm1、Km1、Vm2 、Km2 分别为 1 42s- 1 、 0 53μmol/L、 2 71s- 1 、 1 81 μmol/L。     

空肠弯曲菌基因分型的研究进展

空肠弯曲菌(Campylobacter jejuni,CJ)系螺旋科弯曲菌属胎儿亚种,为一类微需氧嗜热革兰阴性人畜共患病病原体,对人的感染率不亚于沙门菌和志贺菌。现已发现该菌除了引起人类发烧、急性肠炎、反应性关节炎(RA)和格林-巴利综合征(GBS)等疾病外,还可引起牛和绵羊流产,火鸡肝炎和蓝冠病,童子鸡和雏鸡坏死性肝炎,雏鸡、犊牛、仔猪腹泻等多种疾病。CJ广泛分布于温带、亚热带和热带的国家或地区,常通过感染的畜禽污染肉类、牛奶、鸡蛋等食物,多途径传播。常规的流行病学方法一般不能非常准确地确定其传染源,因此分型研究就成为追溯CJ传染源,调…     

海水泵用材料的选择比较

该文通过对铸铁，铜合金及0Cr17Ni12Mo2(日本JIS标准SUS316）不锈钢等3种材料在海水泵中的使用情况进行分析比较，并在为香港地区输送海水而生产制造海水泵的长期实践中证明，使用SUS316不锈钢且严格 控制其铸造工艺和其它热处理工艺，则SUS316具有较强的耐海水腐蚀能力及较高的性能价格比，因此，该材料应用在耐海水泵中具有广阔的发展前景。     

Mechanism of RhoA on vascular reactivity following hemorrhagic shock in rats

AIM: To observe the mechanisms of RhoA on vascular reactivity following hemorrhagic shock (HS) in rats. METHODS: The superior mesenteric artery (SMA) in rats subjected to hemorrhagic shock was adopted to assay the vascular reactivity via observing the contraction initiated by norepinephrine (NE) with isolated organ perfusion system. Meanwhile, the effects of Rho kinase, myosin light chain phosphatase (MLCP), myosin light chain kinase (MLCK) on RhoA regulating vascular reactivity were observed. The effects of RhoA agonist U-46619 and inhibitor C3 enzyme on the activities of Rho kianse, MLCP, MLCK and phosphorylation of MLC20 in the vascular smooth muscle cells (VSMC) with hypoxia were also measured. RESULTS: As compared to control group, the cumulative dose-response curves of SMA to NE at 2 h after shock shifted to the right, the maximal contractions (Emax) of NE was significantly decreased. RhoA agonist U-46619 increased the vascular reactivity in the late period of shock. C3 enzyme abolished U-46619 induced the increase in the contractile response of SMA to NE. Rho kinase inhibitor Y-27632 decreased U-46619-induced the increase in the vascular reactivity, MLCP inhibitor calyculin further promoted the increase in the vascular reactivity. However, MLCK inhibitor had no effect on the U-46619-induced change of vascular reactivity. After hypoxia, the activities of Rho kinase and MLCK, and the level of MLC20 phosphorylation were decreased, MLCP activity was increased. RhoA agonist U-46619 increased the activity of Rho kinase and phosphorylation of MLC20, decreased the activity of MLCP, but had no effects on MLCK activity. CONCLUSION: RhoA plays an important role in the regulation of vascular reactivity following shock. The mechanism is closely related to regulating the activities of Rho kinase and MLCP, and increasing the phosphorylation of MLC20 in VSMC.     

控释肥残膜对土壤性质和作物生长的影响

通过室内残膜强化试验，研究了控释肥残膜对土壤性质及作物生长（以花生为例）的影响。结果表明，土壤中残膜含量在0.008范围内，控释肥残膜可明显降低土壤的透水性，提高土壤的田间持水量和保水性，随膜含量的增加，当达到0.010时，土壤的田间持水量却明显降低，透水明显加快，土壤保水性也随之降低。另外随土壤中膜含量的增加，土壤容重降低，土壤比重变化不大，土壤孔隙度明显增加。强化试验结果进一步表明，在一定的土壤残膜含量范围内，随膜含量的增加，花生生长也呈增加趋势，其中最适宜花生生长的土壤膜含量范围为0.00426－0.00574。控释肥残膜在一定范围内对土壤和作物是有益的。     

利用SDS-PAGE鉴定转基因小麦HMW-GS的表达类型和后代遗传

采用SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)在蛋白质水平上对T2～T5代小麦转基因株系高分子量谷蛋白亚基(HMW—GS)的遗传表达及其分离进行了鉴定和分析。结果发现，外源1Dx5和1Dy10基因在T2代部分株系中表达；在有的株系中出现了原亚基(8亚基)的缺失或沉默和新亚基(暂定8^*)的产生，因而检测出2 5 10 12，2 5 7 8^* 10 12，5 7 10，2 7 10 12的多种类型。对2 5 10 12型株系进行了多代跟踪分析，发现其在T2～T5代陆续发生分离，存在于不同单株、不同单穗的子粒和同一单粒后代之间。经筛选，获得了天然不存在的亚基类型为2 5 10 12，2 10 12，2 5 12等稳定表达的种质创新株系。     

Identification of resistance gene analogue markers closely linked to wheat powdery mildew resistance gene Pm31

Specific oligonucleotide primers, designed for the sequences of known plant disease resistance genes, were used to amplify resistance gene analogues (RGAs) from wheat genomic DNA. This method was applied in a bulked segregant analysis to screen for the RGA markers linked to the powdery mildew resistance gene Pm31, introgressed into common wheat from wild emmer. Two RGA markers (RGA200 and RGA390) were found to be closely linked to Pm31 and completely co‐segregating with the marker allele of Xpsp3029 linked to Pm31, with a genetic distance of 0.6 cM. These two RGA markers were then integrated into the formerly established microsatellite map of Pm31 region. The result showed the effectiveness of the RGA approach for developing molecular markers linked to disease resistance genes and demonstrated the efficiency of denaturing polyacrylamide‐gel electrophoresis for detecting polymerase chain reaction polymorphism.     

用激光剥蚀电感耦合等离子体质谱研究小麦籽粒元素的共分布

增加粮食可食用部分微量营养元素的浓度, 需要更好地了解其在植株, 特别是籽粒内的运输和分布规律。激光剥蚀电感耦合等离子体质谱(laser ablation inductively coupled plasma mass spectrometry, LA-ICP-MS)是一种测定植物组织中元素空间分布的新技术。采用该技术对成熟小麦籽粒中锰(Mn)、铜(Cu)、锌(Zn)和磷(P)的空间分布及其关联程度定量研究。结果表明, 所测元素在籽粒不同部位的浓度分布差异很大。Cu、Zn和P浓度均以糊粉层最高, 胚乳最低, 胚居中, 浓度最大差异分别达15、42和33倍; Mn浓度则以胚最高, 胚乳最低, 糊粉层居中, 浓度最大差异达9倍。籽粒同一部位不同位置的元素浓度亦不相同, 外周胚乳(靠近糊粉层)的元素浓度大于内侧胚乳部位对应元素的浓度, 胚最外侧盾片部位的元素浓度大于胚中间位置的元素浓度, 且各元素趋势一致。比较分析发现, 麦粒不同部位元素的浓度变化存在明显的同步性, 籽粒中P浓度高的部位金属元素(Mn、Cu和Zn)浓度也高。这说明不同元素在向籽粒不同部位运输和积累过程中可能存在密切关联性。     

黑龙江省乳业发展的战略分析与选择

运用SWOT模型分析了黑龙江省乳业发展与战略选择.研究表明:黑龙江省乳业在奶源、产业基础、宏观政策和技术整合方面具有优势,农村地区乳品消费需求的增长、"禁鲜令"的废止和"三聚氰胺"事件也为黑龙江省乳业的发展提供了机遇,但是由于现有的奶源利用效率较低、技术设备水平不高、产品市场竞争力不足、产业整合缓慢和人才外流等问题,黑...