营养元素对木霉菌防治甜瓜枯萎病效果的影响

为明确各种营养元素在木霉菌防治甜瓜枯萎病生防体系中的作用,研究了9种营养元素铜、锌、铁、硼、钼、钙、锰、镁及钾对甜瓜枯萎病菌菌丝生长、木霉菌T23菌丝生长及产孢量、甜瓜种子萌发及根系生长的影响.结果表明:10～1000μg/mL的硫酸铜、硫酸锌、硫酸亚铁及硼酸对镰孢菌菌丝生长有较强的抑制作用,而对木霉菌的抑制作用远小于镰孢菌.适量加入钼酸铵、硫酸亚铁、硫酸钙及磷酸二氢钾有利于木霉菌菌丝生长及孢子形成,对甜瓜种子萌发及胚根生长也有较强的刺激作用.木霉菌结合钼酸铵、硫酸锰和硫酸钙处理土壤能显著降低甜瓜枯萎病的病情指数,相对防效分别为73.95%、73.77%和71.36%.     

侵染西瓜的小西葫芦花叶病毒的生物学特性鉴定

西瓜病毒病是制约西瓜产量及品质的顽疾.据报道,该病害造成的经济损失达到30%～50%.1981～1999年皖、苏、鲁、豫西瓜的病毒病曾几次大发生.危害西瓜的病毒病有西瓜花叶病毒1号(WMV-1)、西瓜花叶病毒2号(WMV-2)、黄瓜花叶病毒(CMV)、烟草花叶病毒(TMV)、烟草环斑病毒(TRSV)、南瓜花叶病毒(SqMV)等32种[1].小西葫芦花叶病毒(ZYMV)是侵染葫芦科的主要病毒之一,1973年首次在意大利北部发现此病毒,至今已成为一个全球性的植物病毒[2].笔者对ZYMV合肥分离物的生物学特性进行了研究.     

玉米叶片受新月弯孢菌侵染后的细胞病理学变化

 本文利用透射电子显微镜技术与细胞化学技术研究了玉米叶片受弯孢菌侵染后的超微结构和细胞壁的组成成份变化。透射电镜观察发现,病菌侵入后,菌丝先在寄主细胞间扩展,随着寄主细胞病变、坏死,菌丝可进入寄主细胞形成胞内菌丝。随病菌侵入和在寄主体内扩展,寄主细胞先后发生了一系列的超微结构变化,叶绿体、液泡等细胞器解体,出现质壁分离现象,并最终解体、坏死、变形。细胞化学标记定位发现,受侵寄主细胞壁中纤维素、木聚糖和果胶质的标记密度明显低于未接种的健康组织,表明细胞壁降解酶(如纤维素酶、木聚糖酶和果胶酶)的产生与病菌侵染和致病过程密切相关。     

Model establishment and biological behaviour observation of mouse blastocyst co-cultured with hepatocarcinoma cell lines with differently invasive and metastatic potential in vitro

AIM: To explore interaction and biological behaviour changes of two kinds of cells-blastocysts and hepatocarcinoma cells in the same microenvironment. METHODS:The models of mouse blastocysts co-cultured with human hepatocarcinoma cell lines were established, then biological behaviours and mutual effects of the two kinds of cells in co-culture system were observed. RESULTS: Compared with control group, hepatocarcinoma cells with differently invasive and metastatic potential significantly enhanced the rates of blastocyst hatchment , attachment and outgrowth(P＜0.05). There was no significant difference in those among hepatocarcinoma cells co-cultured groups (P＞0.05). The blastocyst hatched and attached to hepatocarcinoma cells with differently invasive and metastatic potential. Then, differential trophoblasts invaded hepatocarcinoma cells. The clear-cut interfaces were gradually formed between both sides. Hepatocarcinoma cells on interface showed changes of growth direction and cell shapes and did not invade blastocysts. CONCLUSIONS: Hepatocarcinoma cells promoted blastocyst development. Blastocysts implanted and invaded hepatocarcinoma cells with differently invasive and metastatic potential in vitro, which indicate that blastocyst implantation in vitro does not relate with the kinds and differential level of interactional cells and the low selectivity maybe relate with high adaptability of early life.     

Nitric oxide-mediated the cardioprotection of tumor necrosis factor-alpha on cultured neonatal rat cardiomyocytes during hypoxia/reoxygenation

AIM: To investigate the role of nitric oxide synthase (NOS), soluble guanylyl cyclase (sGC) and protein kinase C (PKC) signaling in tumor necrosis factor-α (TNF-α)-induced cardioprotection against hypoxia/reoxygenation (H/R) injury. METHODS: Neonatal rat ventricular myocytes were pretreated with TNF-α or sodium nitroprusside (SNP) or L-arginine (L-Arg), respectively, for 12 h and then subjected to continuous hypoxia for 12 h, followed by reoxygenation for 6 h. The manganese superoxide dismutase (Mn-SOD) activity of the cells was measured after H/R. Myocyte injury was determined by the release of lactic dehydrogenase (LDH). RESULTS: TNF-α (10⁵ U/L) significantly increased the Mn-SOD activity and decreased release of LDH from ventricular myocytes. The cardioprotection against H/R injury was induced by the pretreatment with SNP (5 μmol/L) or L-Arg (5 mmol/L), which was blocked by ODQ (10 μmol/L), the specific sGC inhibitor, and Chel (5 μmol/L), the specific PKC inhibitor. Pretreatment with L-NAME (100 μmol/L), ODQ, Chel, antoxidant 2-MPG (400 μmol/L) or tyrosine kinase inhibitor genistein (50 μmol/L) attenuated the increased Mn-SOD activity and reduced LDH level induced by TNF-α. CONCLUSION: The results suggest that NO may play a role in TNF-α-induced cardioprotection, which is mediated by sGC and PKC.     

蜱传性疾病--莱姆病螺旋体研究进展

莱姆病是一种蜱传性人兽共患病,在我国北方各省广泛流行,其病原体为伯氏疏螺旋体。莱姆病可使皮肤、心脏、关节和神经系统等多种组织器官受损。本文综述了莱姆病螺旋体的形态、种下分类、生化特征、传播媒介和贮存宿主等方面的研究进展"     

犬传染性喉气管炎病毒的分离及鉴定

用犬肾细胞 (MDCK)从疑似犬传染性喉气管炎病毒感染犬的急性期血清中分离到 1株病毒 ,经血凝试验、免疫电镜观察、中和试验、免疫荧光抗体试验、细胞培养特征观察和回归动物试验等鉴定 ,证明所分离的病毒为犬传染性喉气管炎病毒 ,命名为 BJ- JB- 3。     

2个旋毛虫新生幼虫期特异性相似cDNA的克隆及序列分析

利用旋毛虫新生幼虫期特异性 c DNA探针 ,从新生幼虫 c DNA文库中筛选出 2个相似的旋毛虫新生幼虫期特异性 c DNA克隆 ,分别命名为 N5和 N10 ,N5长度为 12 5 0 bp,N10长度为 12 33bp。 NCBI Blast检索表明 ,2个c DNA全长序列均为旋毛虫新基因序列。DNASIS分析表明 ,N5与 N10的开放阅读框架分别为 10 14、10 17bp,编码338、339个氨基酸 ,推导的成熟蛋白氨基酸序列均为 32 1个氨基酸残基 ,相对分子质量推导值分别为 35 30 0和 354 0 0。 2个氨基酸序列中 N端均包含有一信号肽序列 ,可能为分泌性蛋白。NCBI Blast及 Inter Proscan检索表明 ,以上2个氨基酸序列均含有 型核酸酶的功能结构域 ,均编码 型核酸酶 (DNase ) ,且与已报道的旋毛虫包囊形成相关蛋白 P4 3(经鉴定也为 DNase )同源性最高。目前已有的试验结果证实 ,P4 3并未直接参与包囊的形成 ,而是一种与P4 3蛋白同源性非常高的蛋白参与了旋毛虫包囊的形成。由于 N5与 N10为旋毛虫新生幼虫期特异性表达基因 ,也就是在旋毛虫包囊形成的时期表达 ,而且与 P4 3具有较高的同源性 ,并均编码 DNase 蛋白 ,因此 N5、N10具有参与旋毛虫包囊形成的潜在可能     

利用土壤筛选紫花苜蓿高效共生根瘤菌的初步研究

采用西北地区土壤试管栽培法对12株不同地区来源的根瘤茵和2个紫花苜蓿Medicago sativa品种(品系)进行接种效果的研究，旨在使筛选结果尽量接近实际生产环境，筛选出符合实际效果的高效共生菌株。结果表明，紫花苜蓿与根瘤菌之间表现出共生效果的多样性。绝大多数接种根瘤菌的紫花苜蓿在总瘤数、有效瘤数、地上部干质量方面与不接种的对照相比分别增加了7％～240％，10％～367％，7％～150％。根瘤菌与紫花苜蓿品种之间存在着互作关系，且受土壤因子尤其是土壤养分状况的影响。初步筛选出的与2个紫花苜蓿品种(品系)最佳共生匹配的根瘤菌菌株分别是：中苜一号的73317，01006，01055；金皇后的83092，01006，01055。     

夏季狗牙根草坪不同建植方法及秋季交播黑麦草对成坪效果的影响

以狗牙根Cynodon dactylon种子和营养体为材料，在武汉地区，对5种不同建植方法建成的草坪从盖度变化、成坪时间、均一性、建植成本及秋季交播多年生黑麦草Lolium perenne后翌年狗牙根的草坪质量等方面进行综合比较。结果表明：采用夏季建植狗牙根草坪并于秋季交播多年生黑麦草的方法来建植四季常绿草坪，狗牙根采用撒茎覆沙法效果最佳，其他方法依次为开沟埋茎法、闻铺草皮法、穴植草茎法；种子直播法在翌年需重新建坪。