禾谷镰刀菌致病力和致病基因的研究进展

回顾了对禾谷镰刀菌致病机理的研究,总结了禾谷镰刀菌侵染小麦各组织器官的研究进展以及禾谷镰刀菌致病基因的发现和研究。     

Host range and properties of <Emphasis Type="Italic">Tomato chlorotic dwarf viroid</Emphasis>

We characterised the host range and physical properties of Tomato chlorotic dwarf viroid. Among the 46 plant species inoculated with the viroid, two in the family Compositae and 23 in the family Solanaceae were found to be systemic hosts. The viroids in the crude sap from diseased tomato plants were thermally inactivated by heating to 100°C for at least 40 min. These viroids also lost their infectivity when diluted in phosphate buffer to at least 10⁻⁶, or after 3 days of incubation at room temperature. However, the infectivity of the viroids in dried crude sap from the plants persisted throughout the 50-day test period.     

根瘤菌对水稻的感染

将标记基因nifA-lacZ、 nifHDK-lacZ、 nifH-lacZ、 hemA-lacZ通过三亲交配法导入根瘤菌, 然后接种水稻. β-半乳糖苷酶组织化学染色和切片观察表明, 野生型根瘤菌可以感染水稻, 在水稻根的细胞间隙和细胞中有细菌存在. 回接试验证明侵染水稻根的细菌是根瘤菌.     

枣尺蠖核多角体病毒对6种幼虫感染试验

用枣尺蠖核多角体病毒 (CzNPN)天津毒株病毒悬液 ,采用浸叶法 ,浓度为 2 5× 1 0 7PIB/ml,分别感染饲喂枣尺蠖 (ChihuozaoYang)、槐尺蛾 (SemiothisacinerariaBremeretGrey)、柳毒蛾 (LeucomasalicisLinnaeus)、舞毒蛾[Lymantriadispar (Linnaeus) ]、折带黄毒蛾 [(Euproctisflava (Bremer) ]、榆叶蜂 (ArgecaptivaSmith) 6种 3～ 4龄的幼虫 ,仅枣尺蠖 1种幼虫感病死亡 ,而其它 5种幼虫未见到感病症状 ,说明CzNPV对原始寄主枣尺蠖有较强专一性 ,可作为枣尺蠖生物防治的一个重要措施     

安徽省奶牛寄生蠕虫感染情况调查

对安徽省的１０个奶牛场８１４头奶牛寄生蠕虫的感染情况进行了调查。结果发现,有５６．３％的奶牛的粪样中含有寄生蠕虫卵,经鉴定为１３种蠕虫;有４８．３％的奶牛为混合感染（２～８种）。     

关中西部麦田杂草分布及危害损失

调查结果表明,陕西省关中西部麦田杂草主要有２２种,分属１０科２２属,危害严重的有１０种。６个生态区杂草种类,优势组合分布特点有一定差异,尤以地灌区与塬区旱地存在较大差异。影响杂草分布的因素 地理条件外,还有人为传播,耕作栽培,降雨量,化学除措等。     

小麦白粉病菌对国外引入的披碱草属植物的侵染

对采自我国和由美,加,日,捷,斯,阿（阿富汗）和前苏联引入了１８人种的披碱草,用我国小麦白粉病１１个生理小种的混合菌种进行接种,有１５个接种成功,用１４份发病披碱草上产生的白粉病菌分别回接小麦,也全部回拉成功,说明国外的披碱草和我国的一株具同源性,都属于我国小麦白粉病的寄主范围,具中间寄主传播病菌的潜力,对国外披碱草在疆域接壤的邻国间传播新小种等问题进行了讨论。     

农杆菌侵染小麦的优化方案

本实验选用优质高产小麦品种洛阳8716和绵阳19幼胚愈伤作为受体材料,以pCAMBIA3301为载体,GV3101,EHA105,LBA4404农杆菌为供体材料进行侵染过程的优化研究.采用3种菌株,4个浓度梯度:OD600=0.2,0.5,0.7,1.0;3个时间参数:10 min,30 min,60 min;一共36个处理,每个处理4个重复.结果显示,农杆菌GV3101和EHA105,OD600 1.0×10 min和OD600 0.5×30 min两个侵染处理结果比较好,瞬时表达率达到50%-70%.以小麦幼胚愈伤组织为受体,预培养3～5 d,在24±1℃下,共培养3～4 d和350 mg/L羧苄青霉素除菌及5 mg/L PPT筛选处理后,转化效果较好,平均转化率为0.45%.     

Leukocyte response and phagocytic activity in Nile tilapia experimentally infected with <Emphasis Type="Italic">Enterococcus</Emphasis> sp.

This study evaluated the total and differential leukocyte counting and the phagocytic activity in Nile tilapia Oreochromis niloticus experimentally injected with Enterococcus sp. in the swim bladder. Fish were distributed in four treatments in triplicates of non-injected fish, fish injected with 1 ml of sterile saline solution 0.65%, and fish injected with 1 × 10³ and 1 × 10⁶ colony-forming units (CFU) of Enterococcus diluted in 1 ml sterile saline. Twenty-four hours after injection, the fish were anesthetized and the blood collected for white blood cell (WBC) counts, differential counting of WBC, and phagocytic activity of blood leukocytes. The increased numbers of WBC and lymphocytes were followed by decreased number of monocyte after infection. The percentages of phagocytic activities in the blood were 55.3 and 55.9%, respectively, in tilapia injected with 1 × 10³ and 1 × 10⁶ CFU/ml.     

陕西关中小麦白粉病侵染循环研究

１９９０￣１９９３年调研结果表明，小麦白粉病可在关中南北浅山和旱塬麦区越夏，越冬，完成周年侵染循环，模拟圃测定病分生孢子越夏期存活旬平均温度上限为２９．５￣３０．２℃，越夏期病菌分生孢子和子囊孢子２种方式均可侵染稆生麦苗。