不同钠浓度对白三叶草和多年生黑麦草生长的影响

白三叶草对Na 的反应比多年生黑麦草敏感.培养液中的Na 浓度从0.1mmol/L 增至0.5mmol/L 时,其干物质生产下降37%;增至2.5mmol/L 时,干重下降49%,而多年生黑麦草的干重仅降低6%.2种牧草的Na 含量均随培养液Na 浓度的增加而提高,K 含量未受影响.白三叶草的Na 含量低于多年生黑麦草,而K 含量高于多年生黑麦草.试验结果暗示,白三叶草对K 的选择吸收能力较多年生黑麦草强,但耐盐能力较差,生态适应性不如多年生黑麦草广.     

牛流行热病毒灭活疫苗免疫后牛外周血淋巴细胞亚类分布的研究

对牛流行热病毒灭活疫苗免疫并攻每后，牛外周血淋巴细胞亚类的变化进行了研究。结果表明，灭活苗免疫后，牛的CD4^ 显著升高，可能与参与辅助B淋巴细胞合成抗体有关，攻毒后，γδT细胞均显著上升，免疫组在攻毒后3周仍保持在相当的高水平，IL－2Rα阳性细胞在攻毒后高热期也有显著升高，而CD8^ 细胞没有明显变化。     

Detection, identification and significance of phytoplasmas in grasses in northern Australia

Sugarcane yields have been severely reduced by white leaf and grassy shoot phytoplasma diseases in many parts of Asia. Australian sugarcane crops are not known to be affected by these diseases, but plant pathogenic phytoplasmas found in other introduced and native grasses in northern Australia could pose a serious threat to the Australian sugarcane industry. To further evaluate this threat, leaves from plants of 20 grass species, with and without symptoms, were collected during field surveys in northern Australia and tested to determine whether phytoplasmas were present and whether symptoms were reliable indicators of phytoplasma presence. Molecular tools were used to detect and characterize phytoplasmas. Four different phytoplasmas were found in seven grass species known to grow near healthy sugarcane crops. All the phytoplasmas were closely related to sugarcane white leaf phytoplasma (SCWL), one of the phytoplasmas that causes disease in sugarcane in Asia. Four of the host plant species and two of the phytoplasmas were new records. The relationship between symptoms and phytoplasma presence was poor. Because some plants with symptoms tested negative for phytoplasmas, a series of surveys was carried out in which flowers, leaves, roots and stems of two known host plant species, Whiteochloa cymbiformis and Sorghum stipoideum, were tested separately on nine occasions during two wet seasons. This was done to investigate the distribution of phytoplasmas within plants over time. Results showed that spatial and temporal variation of phytoplasmas occurred in these two host plant species. Hence, evaluation of disease distribution within a region requires repeated testing of all plant parts from plants without symptoms, as well as those with symptoms. To date, there is no report of a vector capable of transmitting to Australian sugarcane the phytoplasmas found in grasses in this study. If one is present, or occurs in the future, then native and introduced grasses could constitute a large reservoir of phytoplasma for vectors to draw on. This work provides an early warning for the sugarcane industry that the potential for infection exists.     

鸡白血病病毒抗原ELISA试剂盒的研制和应用

以双抗体夹心酶联免疫吸附试验（ＤＡＳ－ＥＬＩＳＡ）为基本原理，成功地研制出鸡白血病病毒抗原ＥＬＩＳＡ试剂盒，该试剂盒与国外同类试剂盒相比，具备相同的特异性和敏感性，对ＲＡＶ－１纯化样品的最小检出量可达０．７８ｕｇ／ｍｌ，且敏感性高于直接补体结合试验。经初步应用发现，我国商品种鸡群ＡＬＶ阳性率为０．７－１４％，在部分ＳＰＦ鸡群中未检出阳性鸡。     

Recent studies on the enterotropic strain of avian infectious bronchitis virus

Avian infectious bronchitis (AIB) is an economically important disease of chickens. Recent studies have revealed enterotropism by at least one strain of AIB virus with pathological lesions in parts of the gut. This review highlights the findings of the studies so far made on this enterotropic strain of AIB virus.     

马立克氏病毒单克隆抗体杂交瘤细胞株的建立与鉴定

以马立克氏病毒814株(MDV-814)作为免疫用抗原,建立了2个MDV特异性单克隆抗体(McAb)杂交瘤细胞株—4A6、3D7。鉴定结果表明;两株细胞所分泌的McAb均为IgM类免疫球蛋白,具有MDVⅠ型病毒特异性,无中和反应特性和沉淀反应特性。利用两种McAb对国内标准强毒MDV-京1株进行鉴定,肯定其为MDV-Ⅰ型毒株。     

通过病毒分离鉴定和基因检测首次发现虎流感

应用F81猫肾传代细胞，从高热、拒食和间有神经症状的死亡率病科中分离获得1株病毒，经形态学、理化学、生物学和血清学系统鉴定，证明为流感病毒。采用流感病毒核蛋白基因引物，对分离病毒及该虎病科进行RT－PCR扩增和序列分析，结果从分离病毒和虎病科中均扩增出与理论值大小相符的464bp基因片段；其序列与A、B、C3型流感病毒相比较，同源性分别为84．9％、35．0％、24．8％。由此说明，所分离病毒为A型流感病毒，命名为/蘧／哈尔滨（中国）／01／2002。用此分离病毒静脉接种于3月龄家猫3号，均出现与病虎相似的临床症状，其中1号耐过，2只死亡。死亡猫剖检变化与死虎相似，主要是呈肺炎病变，并可从病科中回收到所接种病毒。从此分离病毒为HA抗原，进行虎与猫血清的HI抗体检测，结果康复虎血清比其病初血清、康复猫血清比其接种前血清HI抗体均增高4倍以上，表明该病毒具有致病性，是引起该虎与试验猫发病甚至死亡的病原。     

禽白血病病毒J亚群(ALV-J)的攻毒试验

将禽白血病病毒 J亚群 (AL V- J)内蒙株 NM876 1和 NM9996人工接种于 1日龄爱维茵肉种鸡 ,通过眼观、病理组织学检查观察了攻毒鸡的病理学特征 ;通过 PCR和 EL ISA技术检测了病毒感染率、抗体变化规律以及病毒和抗体的相关性。结果显示 ,攻毒鸡从第 3周开始即可检出病毒 ,NM876 1株和 NM9996株病毒感染率分别为 71.4 %和6 4 .3% ;从第 5周开始 ,出现较明显的病理学变化 ,病变特征以骨髓、肝脏、心脏、脾、卵巢等组织内髓细胞增生为主 ,而法氏囊、脑、坐骨神经无变化 ;攻毒鸡抗体消长变化有一定的规律 ,一般在 7～ 8周龄和 18～ 2 0周龄时分别出现 1次高峰 ,而在 4～ 6周龄、10周龄和 2 3周龄分别出现 1次低谷 ,提示鸡场进行 EL ISA检测时要避开这一时期 ;攻毒鸡产生耐受性病毒血症 ,即病毒阳性而抗体阴性 (V A- )的比例较高 (7/14 ,9/14 )。通过以上的研究证明 ,AL V- J内蒙株疾病模型复制成功 ,NM876 1、NM9996可作为原型株进行相关研究     

关中驴对6株动物病毒抗原的免疫应答试验

以关中驴为试验动物 ,用猪瘟病毒(HCV )、犬细小病毒 (CPV )、兔瘟病毒(RHDV)、鸡新城疫病毒 (NDV)、伪狂犬病毒(PRV)等病毒进行免疫 ,检测所产生的抗体效价 ,并与猪、鸡、兔、犬、及猫等动物进行比较。试验结果表明 ,关中驴与对照动物产生的抗体效价一致 ,证明了关中驴可替代其它动物用于生物制品研究     

绵羊慢病毒自然感染绵羊的硬化性淋巴细胞性乳腺炎

７头来自新疆南部某绵羊慢病毒（ＯｖＬＶ）感染的羊场的绵羊用于本研究。用琼脂凝胶免疫扩散检查绵羊血清中对绵羊进行性肺炎（ＯＰＰ）病毒（ＯＰＰＶ）的抗体，结果表明有６例呈阳性，１例阴性，抗体效价在３年中呈下降趋势。４例血清学阳性边菜羊和１例阴性和田羊有不同程度的硬化性（纤维性）淋巴细胞性乳腺炎，小叶内有不等的淋巴细胞浸润，导管周围无淋巴滤泡形成，小叶间大量纤维组织增生。７例的肺、脑、关节、血管均无ＯｖＬＶ性特异性病变。从血清学阳性羊的外周血白细胞中未分离到ＯｖＬＶ。