pH缓冲液诱导冬小麦苗期抗寒的生理机理

为探讨外源pH缓冲液喷施诱导冬小麦苗期抗寒的生理机理,以济麦22为材料,采用盆栽试验的方法,分析了pH缓冲液处理后经低温胁迫的冬小麦叶片相对电导率、相对含水量、气孔导度、丙二醛(MDA)含量和抗氧化酶活性的变化。结果表明,随着低温胁迫时间的延长,冬小麦叶片相对电导率和MDA含量均增加。与对照相比,喷施pH 6.5和pH 6.0的缓冲液降低了相对电导率和MDA含量,且减少了超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的下降幅度,以pH 6.0缓冲液处理效应最为显著,经该处理6d时叶片相对含水量和气孔导度也比对照明显提高。说明适宜的外源pH缓冲液处理可诱导冬小麦酶促和非酶促防御系统抗逆机能的增强,有利于植株经受更长时间低温胁迫。     

藿芪灌注液毒性研究

为了测定小鼠口服藿芪灌注液的急性毒性和长期毒性,评价其安全性,为临床安全用药提供依据,采用最大给药量法进行了急性毒性研究,选择健康小鼠20只,24 h内按40 g/kg体重灌胃给药3次,给药后连续观察10天,测定其1日最大给药量,确定藿芪灌注液的急性毒性。将80只健康大鼠随机分为高、中、低剂量组和对照组,每组雌雄各10只,高、中、低剂量组分别按20、10、3 g/kg体重灌服藿芪灌注液,对照组按20 mL/kg灌服生理盐水,每天一次,连续给药35天,通过临床观察、病理组织学检查、血液生理生化指标测定,研究其长期毒性。结果表明,小鼠口服藿芪灌注液的1日最大给药量为120 g/kg,相当于临床奶牛日用量的600倍。藿芪灌注液不影响大鼠的采食、活动、饮水、增重、脏器指数、血液生理生化指标,不会引起大鼠发病和死亡。说明藿芪灌注液实际无毒,至少在20 g/kg体重给药剂量下大鼠连续给药35天是安全的。     

拮抗链霉菌AFLP分析技术体系的研究(英文)

[Objective] The aim of this study was to investigate the preparation method and amplification system of antagonistic streptomyces DNA templates based on AFLP assays, and also provide a basis for the application of AFLP technology in the analysis of streptomyces or even actinomyces. [Method] The DNAs were extracted by the modified CTAB method and amplified by the Pst Ⅰ/Mse Ⅰ AFLP kit and its reaction system. The amplified products were analyzed by the denatured polyacrylamide gel electrophoresis. [Result] The genomic DNAs of ten antagonistic strains of Streptomyces were extracted and tested. The result of 0.8% agarose gel electrophoresis showed that the major DNA bands were clear without degradation and RNA residue, with the fragment sizes ranging from 37.64 to 40.86 Kb. By ultraviolet spectrophotometry, the OD260/OD280 values varying from 1.625 to 1.833 were obtained. Furthermore, the agarose gel electrophoresis of DNA products digested by Pst Ⅰ/Mse Ⅰ presented the dispersed fluorescent long band, which indicated that the enzymatic hydrolysis was fully carried out. The amplified bands of DNA templates by the screened three pairs of primers were clear with rich polymorphism. [Conclusion] The preparation method and amplification system of DNA template established in this study can be used in the AFLP analysis of Streptomyces.