SSR技术及其在果树上的应用

SSR(Simple sequence repeat)技术以其丰富的多态性、共显性遗传、重复性好和操作简便等优点日益受到重视,已成为植物遗传和育种研究中不可缺少的分子标记。对SSR技术的原理和特点作了简要的介绍,较详细地分析了如何获得SSR引物,特别是综述了果树上SSR引物的研究现状,同时将其与其它几种主要的分子标记进行了比较分析,认为SSR标记检测的位点多态性水平明显高于RFLP,而且重复性优于RAPD;着重介绍了SSR技术在果树种质资源和构建果树遗传图谱及基因定位等研究中的应用现状;指出SSR技术将在果树科研上起到重要的作用。     

入世后我国甜樱桃面临的机遇与挑战及发展对策

甜樱桃作为一种早熟、优质、保健果品,而且种植效益较高,在国内国际都正处于发展时期。根据世界甜樱桃生产和贸易情况,指出了我国在甜樱桃科学技术与生产上与世界先进甜樱桃生产国的差距,分析了我国加入WTO之后,我国甜樱桃面临的机遇和挑战,并且机遇大于挑战。如果有适当的科技投入,我国甜樱桃产业将可克服现在科技滞后的状态,发挥我国劳动力低廉和国土辽阔的优势,迅速扩大其生产总量,提高品质,扩大出口,增加农民的收入,2015年可望形成32.4～43.2亿元的社会总产值。     

Metallothionein inhibits homocysteine-induced proliferation of rat vascular smooth muscle cells

AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [³-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10^-6-10^-4 mmol/L) stimulated [³-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [³-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10^-6-10^-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl₂ for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.     

In vitro growth inhibition effects of rhHGF/cHGF on SMMC-7721 human HCC cell line

AIM:To examine the effects of recombinant human hepatocyte growth factor(rhHGF) and native calf HGF(cHGF) on SMMC-7721 human hepatocellular carcinoma(HCC) cell line. METHODS:Human HCC cell line culture, photometric assay, and flow cytometric assay were used in this study .RESULTS:A similar type of dose-dependent cell growth inhibition effect on SMMC-7721 human HCC cells by rhHGF(5-20 μg/L) as well as by cHGF(25-100 mg/L) had been found, with the maximal effect at the highest concentration used. Approximately over 50% of the cells treated with rhHGF(5 μg/L, 10 μg/L, 20 μg/L) accumulated in the quiescent G₀/G₁ phase of the cell cycle over incubation periods for 3 d. CONCLUSION:The growth of SMMC-7721 human HCC cells was strongly inhibited by both rhHGF and cHGF. This might be because the cells exposed to HGF became arrested in the G₀/G₁ phase.     

Establishment of chronic obstructive pulmonary disease rat models by passive cigarette smoking and intratracheal instillation of lipopolysaccharide

AIM:To establish rat chronic obstructive pulmonary disease(COPD) models by passive cigarette smoking plus intratracheal instillation of lipopolysacchride(LPS) or passive cigarette smoking only, which would be similar to the pathogenesis of human COPD. METHODS:48 Wistar rats were randomly divided into 4 groups.(1) Healthy control I group(n=12), rats were bred 4 weeks;healthy control II group(n=12), rats were bred for 3months. (2) Model group I (n=12), 200μg lipopolysaccharide(LPS) was instilled intratracheally once for every two weeks and the rats were exposured to 5% of cigarette smoke, 0.5 h/d for 4 weeks.(3) Model group II(n=12),rats were exposed to 5% of cigarette smoke, 0.5 h/d for 3 months. The pathologic changes of airways and lung tissues, pulmonary function and blood gas analysis were determined. The airway wall lymphocytes and alveolar macrophages were counted. The cross areas of epithelial layer, smooth muscle layer and lamina propria of bronchi were measured. The hydroxyproline of lung tissue homogenates was determined by biochemistry method.RESULTS:The pathologic changes of airways and lung tissue of two models were similar to but milder than those of COPD patients(biopsy data). The collagen deposition and the cross areas of epithelial layer and smooth muscle layer in airway walls of two model groups were significantly increased than those of control groups(P＜0.01,P＜0.05).FEV_0.3/FVC% of two model groups, PaO₂ and SaO₂ of model I group were significantly decreased, while R_i and R_e in model I group were significantly increased than that of control I group(P＜0.05). The PaCO₂ and the counts of lymphocytes and alveolar macrophages of both model groups were significantly increased than those of the control groups (P＜0.01). Lots of alveolar macrophages had phagocyted smoke granules. The amounts of hydroxyproline of two model groups were significantly increased than those of control group((P＜0.05) and were negatively related to the FEV_0.3/FVC%, respectively (P＜0.01,P＜0.01) and positively related to airway resistance of model I group(P＜0.01). CONCLUSIONS:COPD rat models were successfully established by passive cigarette smoking plus intratracheal instillation of LPS and cigarette smoking only. The pathologic changes were similar but milder than those of COPD patients. The airway obstruction of model I group was more severe than that of model II group, but they have no significant difference.     

Effects of carvedilol,cilazapril and their combination on left ventricular remodeling after acute myocardial infarction in rats

AIM:To compare the effects of carvedilol, cilazapril and their combination on left ventricular remodeling(LVRM) after acute myocardial infarction(AMI) in rats. METHODS: Twenty-four hours after AMI operation, 100 surviving rats were randomly assigned to: ①AMI control(n= 25), ②AMI+carvedilol(1 mg·kg^-1 ·d^-1, n= 25)(C1), ③AMI+cilazapril(1 mg·kg^-1 ·d^-1, n= 25)(Z1), and ④ AMI+combination(n= 25) groups. Sham-operated group(n= 17) were selected randomly. After 4 weeks of therapy with the drugs gastric gavage, hemodynamic and pathological studies were performed. RESULTS: There were no significant differences in MI size among the four AMI groups(all P> 0.05) Left ventricular(LV) end diastolic pressure(LVEDP), volume(LVV), weight(LVW) and septal thickness(STh) were all higher and left ventricular pressure maximal rate of rise and fall(±d p /d t) were lower(all P< 0.01) in AMI group than sham-operated group. The LVEDP, LVV, LVW and STh were all lower and ±dp /dt were higher in Z1, C1, and combination groups than those in AMI group(P< 0.05, P< 0.01), with LVEDP and STh were more lower in the combination group than in the two monotherapy group(P< 0.05, P< 0.01), but there were no significant differences in other variables among the three therapy groups. CONCLUSION: Carvedilol, cilazapril and their combination all can prevent from LVRM after AMI in rats, improve hemodynamics and LV function, with the combination superior.     

小菜蛾对溴氢菊酯抗药性的随机扩增多态性DNA分析

利用室内选育119代的抗溴氰菊酯小菜蛾Plutella xylostella品系和敏感品系，通过反复回交和自交建立近等基因系。用Operon公司合成的20个引物对近等基因系基因组DNA进行PCR扩增。3个引物在抗性品系中分别产生1条特异扩增带，4个引物在敏感品系中分别产生了1～5条特异扩增带。由于在近等基因系中，除了与抗性相关的基因区外，其它的遗传背景是相同的，因此可以认为这些特异带与小菜蛾对溴氰菊酯的抗性有关。     

对鳞翅目害虫有活性的cry1C基因的克隆和表达

在鉴定苏云金芽孢杆菌(Bacillus thuringiensis，简称Bt)Btc001菌株cry基因型的基础上，构建了Btc001菌株质粒DNA HindⅢ片段的文库，并利用聚合酶链式反应-限制性酶切片段多态性(PCIR-RFIP)方法筛选出含有crylC6全长基因的13．5kb大片段，酶切分析得到该片段的物理图谱，BamHI和EcoRI切完成了6．5kb含全长基因的亚克隆，并对这条6．5kb片段亚克隆、测序，序列在国际核酸序列数据库(GenBank)登记(AY007686)，并由Bt杀虫晶体蛋白基因国际命名委员会命名为cry1Cb2基因。根据序列设计了一对用于扩增全长基因的引物S581CB和S381CB，扩增产物插入表达载体pET-21b中，诱导后在大肠杆菌BL21(DE3)中获得高效表达。表达产物对小菜蛾(Plutella xylostella)表现出较高活性，LC50达到7．9μg/ml。     

灰葡萄孢菌nit突变体的诱导及其在营养体亲和性测定中的应用初探

 从山西运城、临汾、长治、晋中、大同等地保护地黄瓜灰霉病病株上采集、分离的分属于3个不同菌丝融合群的8个灰葡萄孢菌单孢菌株,经氯酸盐诱导处理,共获得了抗氯酸盐的硝酸盐利用缺陷突变体(nit突变体)59株,其中nit1型38株,nit3型10株,nitM型11株。所有nit突变株分别在PDA斜面转管培养3次(21 d)后,除6株恢复成野生菌株外,其余多数nit突变菌株表现稳定。来源于同一野生菌株的不同类型nit突变体间或同一菌丝融合群不同野生菌株的nit突变体间可产生互补反应而形成异核体,其中以nitM型突变株互补性最好,在利用nit突变体测定灰葡萄孢菌营养体亲和性时应作为标准菌株。来源于不同菌丝融合群的nit突变体间不能产生互补反应。     

枯草芽孢杆菌B—916防治水稻纹枯病的田间试验

１９９２～１９９４年在田间小区试验比较两个拮抗细菌（Ｂ－９１６、Ｐ－９１）和井岗霉素对水稻纹枯病的防治效果。１９９４～１９９５年在江苏省３个基点上进行了Ｂ－９１６防治纹枯病的大面积示范试验。Ｂ－９１６发酵液在田间对水稻纹枯病的为害有较强的控制能力，发酵含菌量为２．５４×１０１１～２．５４×１０１２ｃｆｕ／ｍＬ时，用量３．７５Ｌ／ｈｍ２的防治效果为５０．０％～８１．０％。