利用远缘杂交创造核果类果树新种质的研究

以桃、杏、李、樱桃、杏梅等果树的 1 4个品种为亲本 ,3年来共进行了 80余个组合的远缘杂交试验 ,探讨了核果类果树远缘杂交的亲和性 ,并对远缘杂种幼胚进行了胚抢救。结果表明 ,铃铛花期授粉的坐果率显著高于初花期授粉 ;同一杂交组合 ,正反交坐果率差异显著 ,母本对远缘杂交亲和性影响很大 ,选择自交亲和或自然坐果率高的种或品种做母本容易克服远缘杂交的不亲和性 ;适宜场强的静电场、He -Ne激光处理及60 Coγ射线与He -Ne激光联合处理花粉 ,均能显著提高花粉离体萌芽率 ,用上述处理的花粉进行的远缘杂交坐果率也明显高于对照 ;60 Coγ射线单独处理则降低了花粉离体萌芽率 ,远缘杂交的坐果率也低于对照 ;对远缘杂种幼胚及时地进行胚抢救 ,并诱导形成多丛芽 ,是克服核果类果树远缘杂种不育性的有效方法。研究并筛选出了李、樱桃胚萌发与生长、多丛芽诱导与增殖以及生根培养等最佳培养基配方。目前已将欧洲甜樱桃×中国樱桃、大石早生李×泰安巴旦水杏及凯特杏×总统李等一批核果类果树远缘杂种定植于露地 ,其中欧洲甜樱桃与中国樱桃的种间杂种是国内外首次获得     

三尖杉枝叶粉末防治花生根结线虫病

采用盆栽及大田小区试验,研究了三尖杉Cephalotaxus fortunei枝叶干粉末对花生根结线虫病的防治效果.盆栽试验结果表明,每盆(2kg土)施用三尖杉枝叶干粉末10、15及20 g三种处理,与对照组相比,初侵染相应推迟4、6、10天,并能减少侵染量,降低根结增长率,显著减轻花生根结线虫病病情.大田小区试验结果与盆栽试验结果相似,每小区(5m2)沟施三尖杉枝叶干粉末120、80、50 g,处理后34及53天的2次平均防治效果分别为89%、82%及50%,施药对照10%益舒宝颗粒剂25g处理(相当于45kg/hm2)为74%.综合使用剂量及花生生长情况,建议沟施150kg/hm2三尖杉枝叶干粉为宜.     

额济纳旗浅层地下水环境研究

通过 2 0 0 3年 4- 5月在黑河下游额济纳分两条路线 (a -a’和b -b’)采集水样 ,分析了额济纳现状水资源特征。远离河道区域水化学类型有HCO3·SO4-Na、Cl·SO4-Na·Ca、HCO3·Cl-Na·Ca和SO4·Cl-Na ;在河道附近或河道地区水化学类型主要是SO4·HCO3-Na ,类型单一 ;研究区矿化度和各离子含量随距离补给源的远近增减而升降 ,表明它们主要依赖于上游补给水量 ;同时 ,额济纳地处干旱区 ,降雨稀少 ,该区植被的生长发育主要依靠浅层地下水 ,地下水环境的改变直接导致了区域生态的变化。     

扫描昆虫雷达实时数据采集、分析系统

利用自行设计、制作的扫描昆虫雷达数据采集分析系统,对扫描雷达回波的VGA图像信号进行单帧采集和多幅序列采集,经过图像处理、参数自动识别和回波的自动分析、计算后可得到昆虫活动的方位、高度、距离、密度、飞行的方向和速度等一系列迁飞活动数据。对迁飞昆虫活动实时监测,实现该类害虫的准确预测和有效治理具有非常重要的作用。     

Effect of EGFP gene transfection on the cell cycle distribution of primary cultured human chondrocytes

AIM: To investigate the effect of enhanced green fluorescence protein (EGFP) gene transfection on the cell cycle distribution of primary cultured human chondrocytes in order to establish a tracking method of cultured human nasoseptal chondrocytes. METHODS: pEGFP-N1 plasmid was amplified in E.coli, and purified by high purity kit. Primary cultured human chondrocytes,which were initially obtained from the nasoseptal cartilage, were cultured in vitro and transferred with pEGFP-N1 by means of electroporation with Amaxa nucleofector device. Transfering process and transient expression were evaluated by laser scanning confocal microscope (LSCM), the transfer efficiency and the cell cycle distribution were evaluated by flow cytometry. RESULTS: There was significant expression of EGFP at 24 h after transferring. The transfection efficiency of pEGFP-N1 into primary cultured human chondrocytes reached 35.37％ at 48 h. It didn't affect the process of cell adherance and had no effect on the cell cycle distribution. CONCLUSION: Primary cultured human chondrocytes, which were transfected with pEGFP, are alive in vitro, and the transferring process doesn't affect the cell cycle distribution. These results suggest that pEGFP-N1 is an ideal transient expression vector for primary cultured human chondrocytes and it might be a well tracer in construction tissue engineered cartilage.     

The ex vivo expansion characteristic of endothelial progenitor cells

AIM: To explore the ex vivo expansion characteristics of the endothelial progenitor cells (EPCs). METHODS: CD34⁺ cells were selected from umbilical cord blood mononuclear cells (MNC) by MiniMACS system, expanded at the same conditions as that for total MNC, coincubation of CD34⁺ and CD34^- from the same donation for EPCs. In addition, we tested the effect of vessel endothelial growth factor (VEGF) and passage on cell differentiation, expansion kinetics and apoptosis. EPCs were determined and quantified by immunocytochemistry and flow cytometry. RESULTS: Coculture of CD34⁺ and CD34^-,total MNC led to a significant increase in the expansion of CD34⁺ cells compared with CD34 enrichment (P＜0.05). There was a trend toward decreased apoptosis in cultures when early passage was performed once the linear cord like structures appeared. There was no significant effect on apoptosis between with VEGF and without VEGF group (P＞0.05). These differentiated EPCs were stained positive for CD34⁺, von Willebrand factor (vWF), KDR, CD31 and incorporate acetylated low-density lipoprotein (LDL). CD34⁺ and AC133⁺cells accounted for 68.2%±6.3% (n=6) and 57.2%±9.8% (n=6) of attaching (AT) cells at day 7 of culture, respectively. CONCLUSIONS: Coculture of CD34⁺ and CD34^- or culture of MNC enhances ex vivo expansion of EPCs. Early passage decreases apoptosis rate, VEGF has no significant effect on ex vivo expansion of EPCs.     

Radioligand binding assay of insulin receptor in rabbit kidney during ischemic and reperfusion

AIM: To observe the change of insulin receptor in rabbit kidney with acute ischemic-reperfusion injury. METHODS: 15 Japanese white rabbits were allocated randomly into control group, ischemic-reperfusion group(IR group). IR group received clamping for 1 h followed by 2 h or 48 h of reperfusion. At 2 h or 48 h after reperfusion, glucose and insulin in serum were determined. Insulin receptor in renal tissue was analyzed by radioligand binging assay(BAD). RESULTS: The level of serum glucose increased after 2 h reperfusion in 2 groups, but in IR group the value increased much more higher than those in control groups(P＜0.05). Plasma insulin of IR group was significantly higher than that in control after 2 h reperfusion(P＜0.05). Scatchard analysis of data resulted in curvilinear profiles, indicating that there are two classes of receptors with different affinity or the presence of a single class of receptors with a negative cooperative hormone-receptor interaction. Data analyzed for a two-site model showed that the values of Bmax₁(high affinity site), Bmax₂(low affinity site) and Kd₁, Kd₂ were significantly lower than that of control (P＜0.05) after 2 h perfusion. 48 h after IR there was no difference of Bmax₁, Bmax₂, and Kd₁ between 2 groups,but Kd₂ of IR group was higher than that of control (P＜0.05). CONCLUSIONS: The results indicate that the effect of intrinsic insulin decreases in the progress of the renal ischemic-reperfusion. The resulting high serum glucose may aggravate renal injury in the progress of ischemic-reperfusion.     

大肠杆菌β-半乳糖苷酶基因缺陷型菌株的筛选

本研究以大肠杆菌(含有β半乳糖苷酶基因)为试验对象，用氮-甲基-氮硝基氮-亚硝基胍对其进行诱导突变，在选择培养基上对突变体菌株进行筛选。结果成功地对鸡消化道共生乳酸菌进行了诱导突变，筛选到了β-半乳糖苷酶基因缺陷型的大肠杆菌受体菌株，从而为构建以β-半乳糖苷酶基因为选择标记的载体表达系统奠定了基础。     

3周龄断奶仔猪胰酶发育规律的研究

以 3周龄断奶仔猪为试验材料 ,研究了断奶对仔猪胰酶活性的影响。试验表明 ,3周龄断奶可以显著降低仔猪胰脏中胰淀粉酶、胰蛋白酶、胰糜蛋白酶和胰脂肪酶的活性 ,且在断奶后 2周继续维持断奶时水平。断奶降低了小肠内容物中胰淀粉酶和胰脂肪酶的活性 ,但空肠和回肠胰蛋白酶、胰糜蛋白酶的活性在断奶后并未下降。     

围产期奶牛能量代谢障碍性疾病的防治进展

奶牛代谢性疾病给奶牛饲养业造成重大经济损失。因此 ,如何搞好奶牛的饲养管理 ,减少代谢病的发生 ,充分发挥其生产潜力 ,是当前奶牛代谢病防治工作中亟待解决的问题。本文主要阐述了围产期奶牛能量代谢障碍病的危害、病因及防治措施