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1.
600 g 冰冻羊垂体经过酸性溶液提取、硫酸铵的分级分离和 DEAE-纤维素柱层析得纯品(1),其得率为0.08g/kg,最后将部分纯品(1)过 Sephadex G-100分子筛,得到高纯的羊生长激素[纯品(2)]。提取的羊生长激素具有相当高的理化均一性,纯品(2):聚丙烯酰胺凝胶电泳呈现一条主带和二条酸性小带;聚丙烯酰胺等电聚焦电泳呈现二条带,其等电点分别为 pH7.35和 pH7.40,SDS—电泳呈现二条很难分开的带,其平均分子量为20 100道尔顿;用DNS-CI 法测得的 N-末端氨基酸是2个,丙氨酸和苯氨酸。纯品(1)理化均一性稍差:SDS—电泳较纯品(2)多出两条分子量低的带;等电聚焦电泳多出六条酸性小带。除此之外,其他理化性质同纯品(2)。用大白鼠胫骨实验测定生物活性,测得纯品(1)可使垂体大白鼠胫骨软骨盘的宽度相对增加79%。未对纯品(2)进行生物活性测定。用羊催乳素放射免疫药盒测定,纯品(1)和纯品(2)与羊催乳素均无交叉反应。 相似文献
2.
Detection of Colletotrichum coccodes and Helminthosporium solani in soils by bioassay 总被引:1,自引:0,他引:1
The sensitivity of a bioassay in detecting soil inoculum of Colletotrichum coccodes and Helminthosporium solani was examined using potato minitubers and microplants. Tests were conducted on soils which were collected from fields in which the interval after a previous potato crop differed, and which were also artificially infested with conidia or microsclerotia. For C. coccodes , determining plant infection based on the occurrence of infected roots after 9–12 weeks was a sensitive method for detecting and quantifying the amount of inoculum in soil. Infestations of less than 0·4 microsclerotia per g soil were detected in artificially infested soils. A semiselective medium, developed for isolating C. gloeosporioides from pepper, detected soil infestations by C. coccodes as low as nine conidia or one microsclerotium per g soil in artificially infested soil. For H. solani , infection on minitubers was a sensitive measure, with soil inoculum of fewer than 10 conidia per g soil being detected. Soil infestation could be quantified by assessing the percentage surface area of minitubers covered by sporulating lesions, which was strongly related to the amount of soil infestation. The results of these bioassay tests were compared with published results for real-time quantitative PCR assays on the same soils. The two methods were in good agreement in artificially infested soils, but the bioassay appeared to be more sensitive with naturally infested soils. 相似文献
3.
采用系统溶剂对南欧丹参Salvia sclarea L.花进行提取,以孢子萌发试验法、抑制菌丝生长速率法和盆栽试验系统测定了粗提物对植物病原真菌的生物活性。结果表明,石油醚为提取南欧丹参花活性成分的最佳溶剂。石油醚提取物在离体条件下能显著抑制多种供试真菌菌丝的生长,其对番茄灰霉病菌Botrytis cinerea的EC50值为77.20 μg/mL;对盆栽小麦白粉病Erysiphe graminis的防护效果为94.94%,治疗效果为84.21%。 相似文献
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U. Merz V. Martinez R. Schwärzel 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(1):71-77
Powdery scab of potato, once established in a field, is difficult to control because of the longevity of the resting spores (cystosori) of the causal organism, Spongospora subterranea f.sp. subterranea. Host resistance is likely to be the most efficient in a long-term control strategy for preventing build-up of field inoculum and spread of the disease. Resistance screening of potato cultivars is mostly done in laborious field trials where disease development is likely to be unpredictable. A bioassay with potato tissue cultured plantlets and cystosori as inoculum is described and was tested for its potential to screen potato cultivars at an early stage for their relative susceptibility to powdery scab by comparing the lab results with field data. With cystosori inoculum of Swiss origin, the laboratory test showed clear differences between the potato cultivars in the severity of zoosporangial root infection which correlated better with ranked tuber infection data, compared to root galling. There are apparent differences in the relative trends in susceptibility between roots and tubers of five selected cultivars when using naturally infested soil instead of prepared cystosori as inoculum in the lab bioassay. Furthermore, differences in the severity of zoosporangial root infection of two selected cultivars were found when cystosori from different countries where used as inoculum. A possible host genotype × pathogen interaction is discussed. The bioassay has the potential to screen and select for resistant material at an early breeding stage thus making field trials not unnecessary but more economical. It will allow the use of a standard set of pathogen collections and facilitate testing for inoculum virulence in infested soils. 相似文献
6.
15种杀虫剂对草地贪夜蛾卵的毒力测定 总被引:2,自引:0,他引:2
采用浸卵法测定了15种杀虫剂对草地贪夜蛾卵的毒力,并比较了不同杀虫剂的毒力水平。结果表明:100 mg/L处理后48 h,甲氨基阿维菌素苯甲酸盐(甲维盐)和灭多威对草地贪夜蛾卵孵化抑制率最高,达到100%,其LC 50分别为12.67 mg/L和16.95 mg/L;而200 mg/L的氯虫苯甲酰胺、多杀霉素、阿维菌素、高效氯氰菊酯、虱螨脲、辛硫磷和杀螟丹分别处理后72 h对草地贪夜蛾卵的孵化抑制率次之,在69.6%~87.65%之间,其LC 50分别为44.1、50.9、78.37、79.0、98.15、126.8 mg/L和137.7 mg/L。依据毒力测定的结果和高效低毒类杀虫剂优先选用的原则,推荐选择甲维盐、氯虫苯甲酰胺、多杀霉素、阿维菌素和高效氯氰菊酯作为防治草地贪夜蛾卵的主要药剂。 相似文献
7.
【目的】研究双酰胺类杀虫剂四唑虫酰胺对斜纹夜蛾的室内生测和田间药效试验。【方法】采用人工饲料混药法测定四唑虫酰胺对斜纹夜蛾3龄幼虫毒力,采用机率值分析方法对数据进行处理,用SAS统计分析系统计算毒力回归方程和LD50。用喷洒药剂悬浮液的方法进行田间试验,使用邓肯新复极差法(DMRT)对不同处理防治效果进行统计分析。【结果】四唑虫酰胺对斜纹夜蛾的LD50为0.58 μg/g,氯虫苯甲酰胺对斜纹夜蛾的LD50为1.12 μg/g,四唑虫酰胺的杀虫活性较高,但与氯虫苯甲酰胺的差异不显著。药后3 d,18%四唑虫酰胺悬浮剂7.5和10 mL/667m2处理对斜纹夜蛾的防效分别为85.00%和87.87%,显著高于5.0 mL/667m2 药剂处理,与5%氯虫苯甲酰胺悬浮剂 45 mL/667m2处理差异不显著。药后7 d,18%四唑虫酰胺悬浮剂 3个浓度处理对斜纹夜蛾的防效与5%氯虫苯甲酰胺 45 mL/667m2处理差异不显著。药后 14 d,18%四唑虫酰胺悬浮剂10 mL/667m2处理的防效显著高于5.0和7.5 mL/667m2药剂处理,但与5%氯虫苯甲酰胺 45 mL/667m2处理差异不显著。【结论】18%四唑虫酰胺悬浮剂对斜纹夜蛾具有良好的的防治效果,且随着浓度增高其防效增大。 相似文献
8.
氟磺胺草醚的生物测定方法研究 总被引:3,自引:0,他引:3
试验利用对氟磺胺草醚敏感的玉米、向日葵、高粱为指示作物,利用土培法研究了不同条件下,氟磺胺草醚不同浓度对作物的抑制作用,并建立了氟磺胺草醚玉米生物测定方法——玉米株高法.试验结果表明,最佳生物测定条件为在27℃条件下,培养120 h.研究结果对土壤中氟磺胺草醚的快速测定和轮作换茬具有重要意义. 相似文献
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